Strgo.com 游神 {夜,流浪去....}
Leraning in
J2EE
࿇ D y l e n ࿇
{ 仅以此笔记祭奠游神这次短暂的安分,宛如这夜. }
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Strgo.com 游神 {夜,流浪去....}
Learning in J2EE
ORALCE.............................................................................................................................................................................................................................................................................................................12
一、选择行...............................................................................................................................................................................................................................................................................................12
1. 简单的 SELECT 语句.................................................................................................................................................................................................................................................................12
2. 处理 NULL .................................................................................................................................................................................................................................................................................12
3. 使用 SQL*PLUS..........................................................................................................................................................................................................................................................................12
4. SQL*PLUS 里规定字段的显示格式..........................................................................................................................................................................................................................................12
5. SQL*PLUS 里规定字段的显示格式例子..................................................................................................................................................................................................................................12
6. 判断题(T/F).................................................................................................................................................................................................................................................................................13
二、限制选择行.......................................................................................................................................................................................................................................................................................13
1. 按指定的规则排序......................................................................................................................................................................................................................................................................13
2. 用 WHERE 限制选择行(1).........................................................................................................................................................................................................................................................13
3. 用 WHERE 限制选择行(2).........................................................................................................................................................................................................................................................13
4. LIKE 操作....................................................................................................................................................................................................................................................................................13
5. 日期字段的比较..........................................................................................................................................................................................................................................................................13
6. 不能用到索引的比较操作符......................................................................................................................................................................................................................................................13
三、单行函数...........................................................................................................................................................................................................................................................................................14
1. 数字函数......................................................................................................................................................................................................................................................................................14
2. 字符函数......................................................................................................................................................................................................................................................................................14
3. 日期函数......................................................................................................................................................................................................................................................................................14
4. 转换函数(1).................................................................................................................................................................................................................................................................................14
转换函数(2)...................................................................................................................................................................................................................................................................................14
转换函数(3)...................................................................................................................................................................................................................................................................................15
转换函数(4)...................................................................................................................................................................................................................................................................................15
5. 输入字符,返回数字的函数.........................................................................................................................................................................................................................................................15
6. 有逻辑比较的函数 NVL(EXPR1, EXPR2)函数........................................................................................................................................................................................................................15
四、从多个表里选取数据记录...............................................................................................................................................................................................................................................................16
1. 数据表间的连接..........................................................................................................................................................................................................................................................................16
2. 数据表间的连接例子..................................................................................................................................................................................................................................................................16
3. 数据表间的连接技巧..................................................................................................................................................................................................................................................................16
4. 如何分析和执行 SQL 语句.........................................................................................................................................................................................................................................................16
五、集合函数 (经常和 group by 一起使用)...........................................................................................................................................................................................................................................17
1. 集合函数列表..............................................................................................................................................................................................................................................................................17
2. 使用集合函数的语法..................................................................................................................................................................................................................................................................17
3. 使用 count 时的注意事项...........................................................................................................................................................................................................................................................17
4. 用 group by 时的限制条件..........................................................................................................................................................................................................................................................17
5. 例子..............................................................................................................................................................................................................................................................................................17
6. 判断题(T/F).................................................................................................................................................................................................................................................................................17
六、子查询...............................................................................................................................................................................................................................................................................................18
1. 查询语句可以嵌套......................................................................................................................................................................................................................................................................18
2. 何处可用子查询?........................................................................................................................................................................................................................................................................18
3. 两个查询语句的结果可以做集合操作......................................................................................................................................................................................................................................18
4. 子查询的注意事项......................................................................................................................................................................................................................................................................18
5. 子查询的例子(1).........................................................................................................................................................................................................................................................................18
子查询的例子(2)...........................................................................................................................................................................................................................................................................18
6.取出结果集的 80 到 100 的 SQL 语句........................................................................................................................................................................................................................................18
七、在执行 SQL 语句时绑定变量..........................................................................................................................................................................................................................................................19
1. 接收和定义变量的 SQL*PLUS 命令.........................................................................................................................................................................................................................................19
2. 绑定变量 SQL 语句的例子(1)....................................................................................................................................................................................................................................................19
3. 绑定变量 SQL 语句的例子(2)....................................................................................................................................................................................................................................................19
4. ACCEPT 的语法和例子..............................................................................................................................................................................................................................................................19
4. DEFINE 的语法和例子...............................................................................................................................................................................................................................................................19
5. SQL*PLUS 里传递参数到保存好的*.sql 文件里.....................................................................................................................................................................................................................20
八、概述数据模型和数据库设计...........................................................................................................................................................................................................................................................20
1. 系统开发的阶段..........................................................................................................................................................................................................................................................................20
2. 数据模型......................................................................................................................................................................................................................................................................................20
3. 实体关系模型 (ERM)概念.........................................................................................................................................................................................................................................................20
4. 实体关系模型例子......................................................................................................................................................................................................................................................................20
5. 实体关系的类型..........................................................................................................................................................................................................................................................................21
6. 校正实体关系的原则..................................................................................................................................................................................................................................................................21
7. 定义结构时的注意事项..............................................................................................................................................................................................................................................................21
8. 完整性约束的要求......................................................................................................................................................................................................................................................................21
9. 把实体关系图映射到关系数据库对象的方法..........................................................................................................................................................................................................................21
10. 实体关系图里符号的含义........................................................................................................................................................................................................................................................21
九、创建表...............................................................................................................................................................................................................................................................................................22
1. ORACLE 常用的字段类型.........................................................................................................................................................................................................................................................22
2. 创建表时给字段加默认值 和约束条件....................................................................................................................................................................................................................................22
3. 创建表的例子..............................................................................................................................................................................................................................................................................22
4. 创建表时的命名规则和注意事项..............................................................................................................................................................................................................................................23
5. 约束名的命名规则和语法..........................................................................................................................................................................................................................................................23
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6. 使用约束时的注意事项..............................................................................................................................................................................................................................................................23
7. 由实体关系图到创建表的例子 s_dept.....................................................................................................................................................................................................................................23
8. 较复杂的创建表例子..................................................................................................................................................................................................................................................................23
9. 通过子查询建表..........................................................................................................................................................................................................................................................................23
10. 用子查询建表的注意事项........................................................................................................................................................................................................................................................24
11. Foreign Key 的可选参数 ON DELETE CASCADE.................................................................................................................................................................................................................24
12. 如果数据库表里有不满足的记录存在,建立约束条件将不会成功....................................................................................................................................................................................24
13. 给表创建和删除同义词的例子................................................................................................................................................................................................................................................24
十、ORACLE 里的数据字典...................................................................................................................................................................................................................................................................24
1. 什么是数据字典?........................................................................................................................................................................................................................................................................24
2. 数据字典里存的内容:..............................................................................................................................................................................................................................................................24
3. 常用的数据字典..........................................................................................................................................................................................................................................................................24
4. 数据字典的分类..........................................................................................................................................................................................................................................................................25
5. 查询数据字典..............................................................................................................................................................................................................................................................................25
十一. 控制数据.........................................................................................................................................................................................................................................................................................25
1 、INSERT(往数据表里插入记录的语句)..................................................................................................................................................................................................................................25
2. 插入字符串类型的字段的注意事项..........................................................................................................................................................................................................................................25
3、UPDATE (修改数据表里记录的语句) ...................................................................................................................................................................................................................................26
4、DELETE (删除数据表里记录的语句) ....................................................................................................................................................................................................................................26
5、 SQL 语句的分类......................................................................................................................................................................................................................................................................26
6、ORACLE 里事务控制 .............................................................................................................................................................................................................................................................26
7. DML 操作的注意事项 ..............................................................................................................................................................................................................................................................26
十二、改变表和约束条件.......................................................................................................................................................................................................................................................................27
1. 改变表的几种情况(1) 运行时会加表级锁................................................................................................................................................................................................................................27
1. 改变表的几种情况(2) 运行时会加表级锁................................................................................................................................................................................................................................27
1. 改变表的几种情况(3) 运行时会加表级锁................................................................................................................................................................................................................................27
2. 删除表及表里的数据..................................................................................................................................................................................................................................................................28
3. 删除表后应该注意的问题..........................................................................................................................................................................................................................................................28
4. 给表加注释 ................................................................................................................................................................................................................................................................................28
十三、创建序列号...................................................................................................................................................................................................................................................................................28
1. 创建序列号里各参数的解释......................................................................................................................................................................................................................................................28
2. 插入自动增长序列号字段的方法 ............................................................................................................................................................................................................................................29
3. 查询序列号的情况......................................................................................................................................................................................................................................................................29
4. 改变序列号..................................................................................................................................................................................................................................................................................29
5. 删除序列号..................................................................................................................................................................................................................................................................................29
6. 不能用序列号的 nextval 和 currval 的地方................................................................................................................................................................................................................................29
十四、创建视图 .....................................................................................................................................................................................................................................................................................29
1. 视图的概念和优点......................................................................................................................................................................................................................................................................29
2. 创建视图的语法..........................................................................................................................................................................................................................................................................29
3. 创建修改视图的例子..................................................................................................................................................................................................................................................................30
4. 查询视图的数据字典..................................................................................................................................................................................................................................................................30
5. 简单和复杂的视图对比..............................................................................................................................................................................................................................................................30
6. 在视图上可以用 DML 命令吗? .................................................................................................................................................................................................................................................30
7. 在视图里使用 WITH CHECK OPTION 约束条件..................................................................................................................................................................................................................30
8. 删除视图......................................................................................................................................................................................................................................................................................31
十五、创建索引.......................................................................................................................................................................................................................................................................................31
1.索引的概念...................................................................................................................................................................................................................................................................................31
2. 什么时候创建索引?....................................................................................................................................................................................................................................................................31
3. B*树索引的结构.........................................................................................................................................................................................................................................................................31
4.创建索引的语法...........................................................................................................................................................................................................................................................................31
5.创建索引的注意事项...................................................................................................................................................................................................................................................................31
6.查询索引的方法...........................................................................................................................................................................................................................................................................31
7. 不用索引的地方..........................................................................................................................................................................................................................................................................32
8. 重建索引的语法..........................................................................................................................................................................................................................................................................32
9. 删除索引......................................................................................................................................................................................................................................................................................32
十六、控制用户访问...............................................................................................................................................................................................................................................................................32
1.权限的类别...................................................................................................................................................................................................................................................................................32
2. 查看当前数据库的用户信息......................................................................................................................................................................................................................................................32
3. 创建新用户..................................................................................................................................................................................................................................................................................32
4 、常用的角色及其权限...............................................................................................................................................................................................................................................................33
5、改变老用户 ..............................................................................................................................................................................................................................................................................33
6、删除用户....................................................................................................................................................................................................................................................................................33
7、角色的概念和管理....................................................................................................................................................................................................................................................................33
8、赋于系统的权限语法和例子....................................................................................................................................................................................................................................................33
9、赋于数据对象级的权限语法和例子........................................................................................................................................................................................................................................34
补充:.......................................................................................................................................................................................................................................................................................................34
(1)在 oralce 上的分页需要用到伪列.(sql 级别的分页).................................................................................................................................................................................................................34
约束..................................................................................................................................................................................................................................................................................................36
笛卡尔积..........................................................................................................................................................................................................................................................................................36
子查询..............................................................................................................................................................................................................................................................................................36
数据库的生命周期:.........................................................................................................................................................................................................................................................................37
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数据库设计的关键因素..................................................................................................................................................................................................................................................................37
范式..................................................................................................................................................................................................................................................................................................37
JDBC ..................................................................................................................................................................................................................................................................................................41
1.引入数据库的必要性............................................................................................................................................................................................................................................................................41
2.JDBC 概念..............................................................................................................................................................................................................................................................................................41
3.odbc 概念................................................................................................................................................................................................................................................................................................41
4.jdbc API..................................................................................................................................................................................................................................................................................................41
jdbc 可以做什么?..........................................................................................................................................................................................................................................................................41
jdbc API 分类...................................................................................................................................................................................................................................................................................41
5.jdbc driver 的四种类型..........................................................................................................................................................................................................................................................................41
6.URL:uniform resource locator.............................................................................................................................................................................................................................................................42
如何使用 JDBC..................................................................................................................................................................................................................................................................................................42
7.JDBC 编程的步骤..................................................................................................................................................................................................................................................................................42
8.建立连接的步骤....................................................................................................................................................................................................................................................................................43
9. Statement 接口的比较...........................................................................................................................................................................................................................................................................44
JDBC 中的异常.........................................................................................................................................................................................................................................................................................45
事务的提交方式.......................................................................................................................................................................................................................................................................................45
五种隔离级别...........................................................................................................................................................................................................................................................................................45
JDBC2.0 新特性........................................................................................................................................................................................................................................................................................47
ResultSet 的增强:..........................................................................................................................................................................................................................................................................47
JNDI.................................................................................................................................................................................................................................................................................................47
DAO:data access Object...................................................................................................................................................................................................................................................................48
OOAD and Database Design..............................................................................................................................................................................................................................................................................49
O/R maping:........................................................................................................................................................................................................................................................................................49
OID 唯一:...............................................................................................................................................................................................................................................................................................49
获取唯一的 OID 的几种方式:...............................................................................................................................................................................................................................................................49
继承关系的映射:...................................................................................................................................................................................................................................................................................49
java 属性=======>数据库字段..................................................................................................................................................................................................................................................51
应用程序分层架构的好处:...................................................................................................................................................................................................................................................................51
常见分层:..................................................................................................................................................................................................................................................................................................51
1. Servlet 是什么?....................................................................................................................................................................................................................................................................................52
2. HTTP 和 Servlets..................................................................................................................................................................................................................................................................................52
3. HttpServlet............................................................................................................................................................................................................................................................................................52
4. 服务方法..............................................................................................................................................................................................................................................................................................52
5. 返回响应..............................................................................................................................................................................................................................................................................................52
6. 支持 Servlet 的 Web 服务器................................................................................................................................................................................................................................................................52
Servlet 的周期.........................................................................................................................................................................................................................................................................................53
1,Servlet 的生命周期.......................................................................................................................................................................................................................................................................53
2. init 方法.......................................................................................................................................................................................................................................................................................53
3. init 方法实例...............................................................................................................................................................................................................................................................................53
3. service 方法.................................................................................................................................................................................................................................................................................53
4. Servlets 的多线程安全...............................................................................................................................................................................................................................................................53
5. SingleThreadModel 接口............................................................................................................................................................................................................................................................53
6. destroy 方法................................................................................................................................................................................................................................................................................53
7. 在 Servlet 终止时处理 Service 线程...........................................................................................................................................................................................................................................54
资源访问...................................................................................................................................................................................................................................................................................................54
1. 分布式 JAVA 技术......................................................................................................................................................................................................................................................................54
2. 转发结果至可视页面.................................................................................................................................................................................................................................................................54
3. 转发请求至新的资源..................................................................................................................................................................................................................................................................54
Servlets 中的持久状态..............................................................................................................................................................................................................................................................................55
1. HTTP 协议中无状态的优缺点...................................................................................................................................................................................................................................................55
2. Cookies.........................................................................................................................................................................................................................................................................................55
3. 设置 Cookie.................................................................................................................................................................................................................................................................................55
4. Sessions........................................................................................................................................................................................................................................................................................56
5. 设置 Sessions...............................................................................................................................................................................................................................................................................56
6. Cookies 和 Sessions 的比较.........................................................................................................................................................................................................................................................56
过滤器.......................................................................................................................................................................................................................................................................................................56
1. 什么是过滤器?...........................................................................................................................................................................................................................................................................56
2. 过滤器的用途.............................................................................................................................................................................................................................................................................56
3. 过滤器放在容器结构什么位置?.............................................................................................................................................................................................................................................57
4. 过滤器的存活周期.....................................................................................................................................................................................................................................................................57
5. 过滤器类和接口..........................................................................................................................................................................................................................................................................57
6. 配置过滤器.................................................................................................................................................................................................................................................................................57
Web 应用程序生命周期事件及监听器(Servlet V2.3 版本以后新增功能)...........................................................................................................................................................................................57
1. 什么是事件监听器?....................................................................................................................................................................................................................................................................57
2. Servlet Context 事件监听器........................................................................................................................................................................................................................................................58
3. HTTP Session 事件监听器..........................................................................................................................................................................................................................................................58
4. Servlet Requst 事件监听器..........................................................................................................................................................................................................................................................58
5. 监听器类的规定..........................................................................................................................................................................................................................................................................58
Hibernate3.0........................................................................................................................................................................................................................................................................................................59
hibernate 入门.....................................................................................................................................................................................................................................................................................................59
一.Hibernate 的简介..................................................................................................................................................................................................................................................................................59
二.Hibernate 的工作原理..........................................................................................................................................................................................................................................................................59
3.Hibernate 框架中的核心接口......................................................................................................................................................................................................................................................60
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操作持久化对象.................................................................................................................................................................................................................................................................................................63
1.Hibernte 中的对象的三种状态..............................................................................................................................................................................................................................................................63
2.Session 的 save().....................................................................................................................................................................................................................................................................................63
3.Session 的 update()方法.........................................................................................................................................................................................................................................................................64
4.Session 的 saveOrUpdate()方法.............................................................................................................................................................................................................................................................64
5.Session 的 delete()方法..........................................................................................................................................................................................................................................................................64
6.homework:级联保存删除修改..............................................................................................................................................................................................................................................................64
8.延迟加载采用属性 lazy 来表示............................................................................................................................................................................................................................................................65
9.Hibernate 中的检索方式........................................................................................................................................................................................................................................................................65
10.cascade 属性一般用于一对多<set>和一对一<one-to-one>元素中..................................................................................................................................................................................................66
事务,并发............................................................................................................................................................................................................................................................................................................66
锁模式.......................................................................................................................................................................................................................................................................................................66
高级映射概念.....................................................................................................................................................................................................................................................................................................66
Hibernate 中的排序.........................................................................................................................................................................................................................................................................67
Java Servlets .......................................................................................................................................................................................................................................................................................................71
什么是 Servlet?.........................................................................................................................................................................................................................................................................................71
CGI 和 Servlet 的优缺点...........................................................................................................................................................................................................................................................................71
Tomcat 的目录结构..................................................................................................................................................................................................................................................................................71
配置 JAVA_HOME 环境变量..................................................................................................................................................................................................................................................................72
WEB 应用的目录结构..............................................................................................................................................................................................................................................................................72
使用 servlet 的步骤...................................................................................................................................................................................................................................................................................73
应用服务器...............................................................................................................................................................................................................................................................................................74
Tomcat 的设置..........................................................................................................................................................................................................................................................................................75
配置 tomcat-users.xml.....................................................................................................................................................................................................................................................................75
配置 web.xml...................................................................................................................................................................................................................................................................................75
表单的处理......................................................................................................................................................................................................................................................................................76
获取客户端提交的信息..................................................................................................................................................................................................................................................................76
客户端向服务器端提交信息..........................................................................................................................................................................................................................................................76
获取 HTTP 请求的头部信息..........................................................................................................................................................................................................................................................76
Servlet 的生命周期...................................................................................................................................................................................................................................................................................77
资源访问...................................................................................................................................................................................................................................................................................................78
1. 分布式 JAVA 技术......................................................................................................................................................................................................................................................................78
2. 转发结果至可视页面.................................................................................................................................................................................................................................................................78
3. 跳转( 转发)请求至新的资源......................................................................................................................................................................................................................................................79
设置属性的四个范围............................................................................................................................................................................................................................................................79
JDBC 编程的步骤.....................................................................................................................................................................................................................................................................................80
容器实例化 servlet 的顺序.......................................................................................................................................................................................................................................................................80
GenericServlet........................................................................................................................................................................................................................................................................80
内部跳转的两种方式......................................................................................................................................................................................................................................................................80
对比 forward 和 include...................................................................................................................................................................................................................................................................81
外部跳转..........................................................................................................................................................................................................................................................................................81
总结...........................................................................................................................................................................................................................................................................................................82
过滤器(Filter)............................................................................................................................................................................................................................................................................................85
什么是过滤器?................................................................................................................................................................................................................................................................................85
过滤器适用于那些地方?................................................................................................................................................................................................................................................................85
过滤器放在容器结构什么位置?..................................................................................................................................................................................................................................................85
Filter 的使用步骤............................................................................................................................................................................................................................................................................85
监听器.......................................................................................................................................................................................................................................................................................................86
JSP:Java Server Page..........................................................................................................................................................................................................................................................................................87
第一章.......................................................................................................................................................................................................................................................................................................88
1.jsp 的工作原理:<比 serlvet 多了翻译阶段>................................................................................................................................................................................................................................88
2.MVC..............................................................................................................................................................................................................................................................................................88
第二章.......................................................................................................................................................................................................................................................................................................88
1.jsp 中的元素.................................................................................................................................................................................................................................................................................88
1)脚本元素...........................................................................................................................................................................................................................................................................88
2)指令元素...........................................................................................................................................................................................................................................................................89
3)动作元素(jsp 中自带的标准标签 ).................................................................................................................................................................................................................................90
3.jsp 注释.........................................................................................................................................................................................................................................................................................90
三种注释的区别....................................................................................................................................................................................................................................................................91
4.page 属性:<%@ page attribute="value"....%>.............................................................................................................................................................................................................................91
第四章 可重用的组件...........................................................................................................................................................................................................................................................................92
1.组件...............................................................................................................................................................................................................................................................................................92
2.POJO(Plain Old Java Object)........................................................................................................................................................................................................................................................92
3.JavaBean........................................................................................................................................................................................................................................................................................92
4.JavaBean 按所处的位置分类.......................................................................................................................................................................................................................................................93
5.根据功能分类...............................................................................................................................................................................................................................................................................93
6.JavaBean 中属性的分类...............................................................................................................................................................................................................................................................93
7.使用 JavaBean 的目的..................................................................................................................................................................................................................................................................93
jsp 中使用 JavaBean:<总>........................................................................................................................................................................................................................................................................94
1、jsp 中获得或者创建 JavaBean 对象.........................................................................................................................................................................................................................................94
2、设置 JavaBean 对象中的属性值...............................................................................................................................................................................................................................................94
3、输出 JavaBean 对象中的属性值...............................................................................................................................................................................................................................................95
4、使用标签<jsp:useBean>的四种方式........................................................................................................................................................................................................................................96
5