目 录
1 前言...........................................................................................................................................1
1.1 边界定义........................................................................................................................................1
1.2 原则定义........................................................................................................................................1
2 格式编排约定...........................................................................................................................2
2.1 基本要求........................................................................................................................................2
2.2 编写规范........................................................................................................................................2
2.2.1 字段排列要求.......................................................................................................................2
2.2.2 字段分割符’,’点书写位置要求 ...........................................................................................2
2.2.3 字段别名 ‘AS’ 语句编写要求 ...........................................................................................2
2.2.4 SELECT 子句排列要求.......................................................................................................3
2.2.5 运算符前后间隔要求...........................................................................................................3
2.2.6 CASE 语句的编写 ...............................................................................................................3
2.2.7 子查询嵌套编写规范...........................................................................................................4
2.2.8 表别名定义约定...................................................................................................................5
3 语法及数据操作约定...............................................................................................................5
3.1 JOIN 操作语法要求 .....................................................................................................................5
3.2 INSERT 语句编写规范................................................................................................................6
3.3 DELETE 语句编写规范...............................................................................................................7
3.4 NULL 值处理约定........................................................................................................................7
3.4.1 数字型字段 NULL 值的处理 ..............................................................................................7
3.4.2 字符型字段 NULL 值的处理 ..............................................................................................7
3.4.3 提取日期型字段的处理.......................................................................................................7
3.5 除法运算被 0 除的处理................................................................................................................7
3.6 比较逻辑运算处理约定................................................................................................................8
3.6.1 字符型比较的处理...............................................................................................................8
3.6.2 日期型比较的处理...............................................................................................................8
3.7 注释约定........................................................................................................................................8
4 小技巧.......................................................................................................................................9
4.1 历史表的数据访问........................................................................................................................9
4.2 横转竖表开发..............................................................................................................................10
