Linq-to-SQL.zip_linq_linqexample_linqtosql

共102个文件

cs：45个

resources：14个

resx：13个

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linq_to_sql

sql

94 浏览量 2022-09-24 16:58:37 上传评论收藏 399KB ZIP 举报

LINQ（Language Integrated Query，语言集成查询）是.NET框架中的一项重要技术，它允许程序员使用类似于SQL的语法在各种数据源上执行查询。在C#编程中，LINQ-to-SQL是LINQ的一个子集，专门用于处理关系数据库。本教程将深入探讨LINQ-to-SQL的基本概念、用法以及在实际开发中的应用。 1. LINQ-to-SQL的基本概念： LINQ-to-SQL是一种对象关系映射（ORM）工具，它可以将SQL Server数据库表映射到C#类，使开发者能够使用面向对象的方式来操作数据库。通过使用LINQ-to-SQL，我们可以避免编写大量SQL语句，而是直接在C#代码中进行数据查询、更新和删除操作。 2. 创建LINQ-to-SQL数据上下文：在开始使用LINQ-to-SQL之前，需要创建一个DataContext类实例，该类代表与数据库的连接。DataContext类会自动映射数据库模式到C#类，并提供对这些类的查询支持。 3. 数据实体类的创建：每个数据库表对应一个C#类，这些类是自动生成的，包含与数据库表列相对应的属性。可以通过在设计视图中拖放数据库表到LINQ-to-SQL设计器，自动生成这些类。 4. LINQ查询语法： - LINQ查询表达式：使用`from`、`where`、`select`等关键字构建查询，如`var result = from customer in customers where customer.City == "London" select customer;` - 方法语法：使用查询操作符如`Where()`、`Select()`、`OrderBy()`等，如`var result = customers.Where(c => c.City == "London").Select(c => c);` 5. 插入、更新和删除操作： LINQ-to-SQL提供了方便的方法来执行CRUD（创建、读取、更新和删除）操作。例如，插入新记录：`db.Customers.InsertOnSubmit(newCustomer); db.SubmitChanges();` 6. 对象跟踪： DataContext会跟踪对数据库对象所做的更改，当调用`SubmitChanges()`时，它会自动处理所有必要的INSERT、UPDATE和DELETE语句。 7. 避免SQL注入：使用LINQ-to-SQL，查询是类型安全的，可以有效防止SQL注入攻击，因为它不直接处理字符串格式化的SQL语句。 8. 执行自定义SQL：虽然LINQ-to-SQL主要是为简化查询而设计的，但也可以通过`ExecuteQuery<T>`或`ExecuteMethodCall`方法执行自定义的SQL语句。 9. 分页和排序： LINQ-to-SQL支持分页查询，如`var result = (from c in customers orderby c.Name select c).Skip(10).Take(10);`，以及按指定字段排序。 10. 异步操作： .NET Framework 4.0及以上版本支持异步LINQ操作，使得在处理大量数据时能提高应用程序性能，如`await customers.OrderBy(c => c.Name).ToListAsync();` LINQ-to-SQL是C#中处理关系数据库的强大工具，它提供了直观的、类型安全的查询接口，简化了数据库操作。通过熟练掌握LINQ-to-SQL，开发者可以更高效地编写和管理数据库相关的代码。在这个例子中，你可以通过阅读提供的"Linq to SQL"文件进一步了解并实践这些概念。

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Linq-to-SQL.zip_linq _linq example_linq to sql_sql （102个子文件）

LinqSql.csproj.GenerateResource.Cache 2KB

WindowsFormsApplication1.csproj.GenerateResource.Cache 1KB

LinqSql.exe.config 410B

LinqSql.vshost.exe.config 410B

app.config 410B

University.designer.cs 28KB

frmMain.Designer.cs 17KB

frmStudent.Designer.cs 15KB

Calendar.cs 13KB

frmStudent.cs 11KB

frmActivity.Designer.cs 9KB

frmProject.Designer.cs 9KB

frmProfessor.Designer.cs 9KB

frmRegisterStudent.Designer.cs 9KB

frmRegisterActivity.Designer.cs 9KB

frmProjectCategory.Designer.cs 8KB

frmRegisterProject.Designer.cs 8KB

frmCategory.Designer.cs 7KB

frmActivity.cs 6KB

frmMain.cs 6KB

PersianNumber.cs 6KB

frmRegisterActivity.cs 5KB

frmProject.cs 5KB

frmProfessor.cs 5KB

frmRegisterStudent.cs 5KB

frmRegisterProject.cs 5KB

frmProjectCategory.cs 4KB

InputForm.Designer.cs 4KB

frmCategory.cs 4KB

SettingClass.cs 4KB

DebuggerWriter.cs 4KB

Professor.cs 3KB

Resources.Designer.cs 3KB

Student.cs 3KB

frmReports.Designer.cs 3KB

SunDate.cs 2KB

Settings.Designer.cs 2KB

Number.cs 2KB

AssemblyInfo.cs 1KB

Project.cs 1KB

MoonDate.cs 1KB

Category.cs 1005B

InputForm.cs 911B

Program.cs 901B

BStudent.cs 662B

frmReports.cs 629B

Activity.cs 477B

MStudent.cs 323B

DateType.cs 143B

University.cs 0B

LinqSql.csproj 10KB

University.dbml 4KB

DataClasses2.designer.cs.dll 28KB

University.designer.cs.dll 19KB

Entity.University.designer.cs.dll 8KB

Properties.Resources.Designer.cs.dll 5KB

DataClasses1.designer.cs.dll 4KB

LinqSql.exe 108KB

WindowsFormsApplication1.exe 31KB

LinqSql.vshost.exe 14KB

University.dbml.layout 6KB

LinqSql.vshost.exe.manifest 490B

WindowsFormsApplication1.vshost.exe.manifest 490B

LinqSql.pdb 266KB

WindowsFormsApplication1.pdb 94KB

LinqSql.Froms.frmActivity.resources 180B

LinqSql.Froms.frmProjectCategory.resources 180B

LinqSql.Froms.frmRegisterActivity.resources 180B

LinqSql.Froms.frmRegisterProject.resources 180B

WindowsFormsApplication1.Properties.Resources.resources 180B

LinqSql.Froms.frmProject.resources 180B

LinqSql.Froms.InputForm.resources 180B

LinqSql.Properties.Resources.resources 180B

LinqSql.frmMain.resources 180B

LinqSql.Froms.frmReports.resources 180B

LinqSql.Froms.frmRegisterStudent.resources 180B

LinqSql.Froms.frmProfessor.resources 180B

LinqSql.Froms.frmCategory.resources 180B

LinqSql.frmStudent.resources 180B

frmMain.resx 6KB

InputForm.resx 6KB

frmReports.resx 6KB

frmStudent.resx 6KB

frmCategory.resx 6KB

frmRegisterStudent.resx 6KB

frmRegisterActivity.resx 6KB

frmActivity.resx 6KB

frmProject.resx 6KB

frmProjectCategory.resx 6KB

frmProfessor.resx 6KB

frmRegisterProject.resx 6KB

Resources.resx 5KB

Settings.settings 2KB

LinqSql.sln 911B

LinqSql.suo 81KB

WindowsFormsApplication1.csproj.FileListAbsolute.txt 5KB

共 102 条

F:\SOHEIL\[ University ]\SP\HomeWorks\Project5\Seshanbe\WindowsFormsApplication1\WindowsFormsApplication1\bin\Debug\WindowsFormsApplication1.exe F:\SOHEIL\[ University ]\SP\HomeWorks\Project5\Seshanbe\WindowsFormsApplication1\WindowsFormsApplication1\bin\Debug\WindowsFormsApplication1.pdb F:\SOHEIL\[ University ]\SP\HomeWorks\Project5\Seshanbe\WindowsFormsApplication1\WindowsFormsApplication1\obj\Debug\ResolveAssemblyReference.cache F:\SOHEIL\[ University ]\SP\HomeWorks\Project5\Seshanbe\WindowsFormsApplication1\WindowsFormsApplication1\obj\Debug\WindowsFormsApplication1.Properties.Resources.resources F:\SOHEIL\[ University ]\SP\HomeWorks\Project5\Seshanbe\WindowsFormsApplication1\WindowsFormsApplication1\obj\Debug\WindowsFormsApplication1.csproj.GenerateResource.Cache F:\SOHEIL\[ University ]\SP\HomeWorks\Project5\Seshanbe\WindowsFormsApplication1\WindowsFormsApplication1\obj\Debug\WindowsFormsApplication1.exe F:\SOHEIL\[ University ]\SP\HomeWorks\Project5\Seshanbe\WindowsFormsApplication1\WindowsFormsApplication1\obj\Debug\WindowsFormsApplication1.pdb F:\SOHEIL\[ University ]\SP\HomeWorks\Project5\Seshanbe\WindowsFormsApplication1\WindowsFormsApplication1\obj\Debug\WindowsFormsApplication1.Form1.resources F:\SOHEIL\[ University ]\SP\HomeWorks\Project5\Seshanbe\WindowsFormsApplication2\WindowsFormsApplication1\obj\Debug\ResolveAssemblyReference.cache F:\SOHEIL\[ University ]\SP\HomeWorks\Project5\Seshanbe\WindowsFormsApplication2\WindowsFormsApplication1\obj\Debug\WindowsFormsApplication1.frmMain.resources F:\SOHEIL\[ University ]\SP\HomeWorks\Project5\Seshanbe\WindowsFormsApplication2\WindowsFormsApplication1\obj\Debug\WindowsFormsApplication1.Froms.frmRegister.resources F:\SOHEIL\[ University ]\SP\HomeWorks\Project5\Seshanbe\WindowsFormsApplication2\WindowsFormsApplication1\obj\Debug\WindowsFormsApplication1.Properties.Resources.resources F:\SOHEIL\[ University ]\SP\HomeWorks\Project5\Seshanbe\WindowsFormsApplication2\WindowsFormsApplication1\obj\Debug\WindowsFormsApplication1.csproj.GenerateResource.Cache F:\SOHEIL\[ University ]\SP\HomeWorks\Project5\Seshanbe\WindowsFormsApplication2\WindowsFormsApplication1\bin\Debug\WindowsFormsApplication1.exe F:\SOHEIL\[ University ]\SP\HomeWorks\Project5\Seshanbe\WindowsFormsApplication2\WindowsFormsApplication1\bin\Debug\WindowsFormsApplication1.pdb F:\SOHEIL\[ University ]\SP\HomeWorks\Project5\Seshanbe\WindowsFormsApplication2\WindowsFormsApplication1\obj\Debug\WindowsFormsApplication1.exe F:\SOHEIL\[ University ]\SP\HomeWorks\Project5\Seshanbe\WindowsFormsApplication2\WindowsFormsApplication1\obj\Debug\WindowsFormsApplication1.pdb F:\SOHEIL\[ University ]\SP\HomeWorks\Project5\Seshanbe\WindowsFormsApplication2\WindowsFormsApplication1\obj\Debug\WindowsFormsApplication1.frmStudent.resources F:\SOHEIL\[ University ]\SP\HomeWorks\Project5\Seshanbe\WindowsFormsApplication2\WindowsFormsApplication1\obj\Debug\WindowsFormsApplication1.Froms.frmProfessor.resources C:\Users\Mohammad\Desktop\SPProject05\WindowsFormsApplication2\WindowsFormsApplication1\obj\Debug\WindowsFormsApplication1.pdb C:\Users\Mohammad\Desktop\SPProject05\WindowsFormsApplication2\WindowsFormsApplication1\bin\Debug\WindowsFormsApplication1.exe C:\Users\Mohammad\Desktop\SPProject05\WindowsFormsApplication2\WindowsFormsApplication1\bin\Debug\WindowsFormsApplication1.pdb C:\Users\Mohammad\Desktop\SPProject05\WindowsFormsApplication2\WindowsFormsApplication1\obj\Debug\ResolveAssemblyReference.cache C:\Users\Mohammad\Desktop\SPProject05\WindowsFormsApplication2\WindowsFormsApplication1\obj\Debug\WindowsFormsApplication1.frmMain.resources C:\Users\Mohammad\Desktop\SPProject05\WindowsFormsApplication2\WindowsFormsApplication1\obj\Debug\WindowsFormsApplication1.Froms.frmProfessor.resources C:\Users\Mohammad\Desktop\SPProject05\WindowsFormsApplication2\WindowsFormsApplication1\obj\Debug\WindowsFormsApplication1.Froms.frmRegister.resources C:\Users\Mohammad\Desktop\SPProject05\WindowsFormsApplication2\WindowsFormsApplication1\obj\Debug\WindowsFormsApplication1.frmStudent.resources C:\Users\Mohammad\Desktop\SPProject05\WindowsFormsApplication2\WindowsFormsApplication1\obj\Debug\WindowsFormsApplication1.Properties.Resources.resources C:\Users\Mohammad\Desktop\SPProject05\WindowsFormsApplication2\WindowsFormsApplication1\obj\Debug\WindowsFormsApplication1.csproj.GenerateResource.Cache C:\Users\Mohammad\Desktop\SPProject05\WindowsFormsApplication2\WindowsFormsApplication1\obj\Debug\WindowsFormsApplication1.exe F:\Other Projects\SP LING\LINQ to SQL\Linq to SQL\WindowsFormsApplication1\obj\Debug\WindowsFormsApplication1.exe F:\Other Projects\SP LING\LINQ to SQL\Linq to SQL\WindowsFormsApplication1\obj\Debug\WindowsFormsApplication1.pdb

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