EF6 在 SQLite中使用备忘

== 菜鸟级选手试验在EF6中使用Sqlite，零EF基础，少量Sqlite基础。经过断断续续的很长时间 - _ -！

>>连接

1. 安装

使用目前最新版本EF6.1，Sqlite1.0.93.0。直接NuGet安装：

2. 配置

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<?xml version="1.0" encoding="utf-8"?> <configuration>   <configSections>     <section name="entityFramework" type="System.Data.Entity.Internal.ConfigFile.EntityFrameworkSection, EntityFramework, Version=6.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" requirePermission="false" />     <!-- For more information on Entity Framework configuration, visit http://go.microsoft.com/fwlink/?LinkID=237468 -->   </configSections>   <startup>     <supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.5" />   </startup>   <connectionStrings>     <add name="SqlliteEF6" connectionString="Data Source=Data\EF6.db" providerName="System.Data.SQLite" />  </connectionStrings>   <entityFramework>     <providers>       <provider invariantName="System.Data.SQLite" type="System.Data.SQLite.EF6.SQLiteProviderServices, System.Data.SQLite.EF6" />       <provider invariantName="System.Data.SQLite.EF6" type="System.Data.SQLite.EF6.SQLiteProviderServices, System.Data.SQLite.EF6" />     </providers>     <defaultConnectionFactory type="System.Data.Entity.Infrastructure.LocalDbConnectionFactory, EntityFramework">       <parameters>         <parameter value="v11.0" />       </parameters>     </defaultConnectionFactory>   </entityFramework>   <system.data>     <DbProviderFactories>       <remove invariant="System.Data.SQLite" />       <add name="SQLite Data Provider" invariant="System.Data.SQLite" description="Data Provider for SQLite" type="System.Data.SQLite.SQLiteFactory, System.Data.SQLite" />       <remove invariant="System.Data.SQLite.EF6" />       <add name="SQLite Data Provider (Entity Framework 6)" invariant="System.Data.SQLite.EF6" description=".Net Framework Data Provider for SQLite (Entity Framework 6)" type="System.Data.SQLite.EF6.SQLiteProviderFactory, System.Data.SQLite.EF6" />     </DbProviderFactories>   </system.data> </configuration>

3. 设置数据库

EF中数据库操作继承DBContext。需要指定数据连接，名称和config配置一致，否则默认使用Sqlserver。

SQLite可以重载创建。

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public class EF6Context : DbContext     {         public EF6Context(string databaseName = "SqlliteEF6")             : base(databaseName)         {         }           public DbSet<User> Users { set; get; }           protected override void OnModelCreating(DbModelBuilder modelBuilder)         {}      }

>>注意事项

1. Sqlite中不能自动创建数据库和新建表，需要额外的操作

>> 数据类型插入获取

1. 自增ID

Sqlite中需要设置AUTOINCREMENT，如下：

1	Id INTEGER PRIMARY KEY AUTOINCREMENT,

需要引用System.ComponentModel.DataAnnotations，System.ComponentModel.DataAnnotations.Schema，类中写明

1 2	[Key, DatabaseGenerated(DatabaseGeneratedOption.Identity)] public Int64 Id { get; set; }

2. 限定Table

默认数据库获取为DBContext中定义的名称，限定对应的Table，需要在类上指明，如下：

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[Table("User")] public class User {...

3. 枚举型

目前直接能使用，注意需要在定义表时限定不能为NULL,否则为NULL时获取会报错。定义时如下定义：

1	public enum TestENUM : long { A, B, C };

4. 其它

目前SQlite中支持浮点数、时间、二进制数据、字符串等。创建表示例：

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NorthwindContext context = new NorthwindContext();            string sql = @" CREATE TABLE User (    Id INTEGER PRIMARY KEY AUTOINCREMENT,    Name varchar (20),    Time timestamp,    Data blob,    Val REAL,    TestE INTEGER);";            context.Database.ExecuteSqlCommand(sql, new object[1]);

定义类示例：

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[Table("User")] public class User {     public enum TestENUM : long { A, B, C };       [Key, DatabaseGenerated(DatabaseGeneratedOption.Identity)]     public Int64 Id { get; set; }     [StringLength(30)]     public string Name { get; set; }       public byte[] Data { get; set; }       public double Val { get; set; }       public DateTime Time { get; set; }     public TestENUM TestE { get; set; }  }

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public class EF6Context : DbContext     {         public EF6Context(string databaseName = "SqlliteEF6")             : base(databaseName)         {         }           public DbSet<User> Users { set; get; }           protected override void OnModelCreating(DbModelBuilder modelBuilder)         {}      }

调用示例：

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NorthwindContext context = new NorthwindContext(); context.Users.Add(new User() { Data = new byte[] { 1, 2, 3, 4 }, Name = "aa22", Time = DateTime.Now, Val = 2.2, TestE  = User.TestENUM.B }); context.SaveChanges();

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NorthwindContext context = new NorthwindContext(); context.Users.OrderBy(c => c.Name).Load(); this.dataGrid.ItemsSource = context.Users.Local;

以上代码测试正常。源码下载

来自为知笔记(Wiz)