Entity Framework 6连接Postgresql、SQLite、LocalDB的注意事项和配置文件

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Postgresql

Postgresql支持Code First的方式自动生成表，不过默认的模式是dbo而不是public，而且还可以自动生成自增主键。




<?xml version="1.0" encoding="utf-8"?>
<configuration>
<configSections>
<!-- For more information on Entity Framework configuration, visit http://go.microsoft.com/fwlink/?LinkID=237468 -->
<section name="entityFramework" type="System.Data.Entity.Internal.ConfigFile.EntityFrameworkSection, EntityFramework, Version=6.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" requirePermission="false" />
</configSections>
<entityFramework>
<defaultConnectionFactory type="System.Data.Entity.Infrastructure.LocalDbConnectionFactory, EntityFramework">
<parameters>
<parameter value="v11.0" />
</parameters>
</defaultConnectionFactory>
<providers>
<provider invariantName="System.Data.SqlClient" type="System.Data.Entity.SqlServer.SqlProviderServices, EntityFramework.SqlServer" />
<provider invariantName="Npgsql" type="Npgsql.NpgsqlServices, Npgsql.EntityFramework" />
</providers>
</entityFramework>
<system.data>
<DbProviderFactories>
<remove invariant="Npgsql"></remove>
<add name="Npgsql Data Provider"
invariant="Npgsql"
description=".Net Framework Data Provider for Postgresql Server"
type="Npgsql.NpgsqlFactory, Npgsql" />
</DbProviderFactories>
</system.data>
<connectionStrings>
<add name ="BrKxxContext" connectionString ="server=127.0.0.1;User Id=postgres;password=energy;database=eftest" providerName="Npgsql"/>
</connectionStrings>
</configuration>



SQLite

SQLite不支持Code First的方式自动生成表，所以可能会报找不到相应的table的错误，没办法只能自己手动建表了，另外，SQLite虽然支持INTEGER类型的自增主键，但是INTEGER在C#中对应的是long或者Int64的类型，这个是要注意的，给Model设置主键时一定要设对类型，不然会出问题。




<?xml version="1.0" encoding="utf-8"?>
<configuration>
<configSections>
<!-- For more information on Entity Framework configuration, visit http://go.microsoft.com/fwlink/?LinkID=237468 -->
<section name="entityFramework" type="System.Data.Entity.Internal.ConfigFile.EntityFrameworkSection, EntityFramework, Version=6.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" requirePermission="false" />
</configSections>
<connectionStrings>
<add name="BrKxxContext" providerName="System.Data.SQLite.EF6" connectionString="Data Source=|DataDirectory|BrKxx.db;Pooling=True" />
</connectionStrings>
<system.data>
<DbProviderFactories>
<remove invariant="System.Data.SQLite" />
<add name="SQLite Data Provider" invariant="System.Data.SQLite" description=".Net Framework 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>
<entityFramework>
<defaultConnectionFactory type="System.Data.Entity.Infrastructure.LocalDbConnectionFactory, EntityFramework">
<parameters>
<parameter value="v11.0" />
</parameters>
</defaultConnectionFactory>
<providers>
<provider invariantName="System.Data.SqlClient" type="System.Data.Entity.SqlServer.SqlProviderServices, EntityFramework.SqlServer" />
<!--<provider invariantName="System.Data.SQLite.EF6" type="System.Data.SQLite.EF6.SQLiteProviderServices, System.Data.SQLite.EF6" />-->
<provider invariantName="System.Data.SQLite" type="System.Data.SQLite.EF6.SQLiteProviderServices, System.Data.SQLite.EF6" />
</providers>
</entityFramework>
</configuration>



LocalDB

1、如果是单独只安装LocalDB的情况下，LocalDB不会自动开启默认的进程，需要通过提供的SqlLocalDB.exe来创建或者开启相应的进程

2、如果部署的机器上只安装了.NET 4.0的运行环境，那么你的应用程序将无法访问LocalDB，你需要安装.NET 4.0.2以上的版本才能正常的访问LocalDB




<?xml version="1.0" encoding="utf-8"?>
<configuration>
<configSections>
<!-- For more information on Entity Framework configuration, visit http://go.microsoft.com/fwlink/?LinkID=237468 -->
<section name="entityFramework" type="System.Data.Entity.Internal.ConfigFile.EntityFrameworkSection, EntityFramework, Version=6.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" requirePermission="false"/>
</configSections>
<entityFramework>
<defaultConnectionFactory type="System.Data.Entity.Infrastructure.LocalDbConnectionFactory, EntityFramework">
<parameters>
<parameter value="v11.0"/>
</parameters>
</defaultConnectionFactory>
<providers>
<provider invariantName="System.Data.SqlClient" type="System.Data.Entity.SqlServer.SqlProviderServices, EntityFramework.SqlServer"/>
</providers>
</entityFramework>
<connectionStrings>
<add name="BrKxxContext" providerName="System.Data.SqlClient" connectionString="Data Source=(LocalDb)\v11.0;Initial Catalog=BrKxx;AttachDbFilename=|DataDirectory|BrKxx.mdf;Integrated Security=True;"/>
</connectionStrings>
</configuration>



最后

DataDirectory一般是指App_Data，如果使用默认值得情况下，提示找不到数据库文件，或者你想把数据库文件放在指定的路径下，就需要在程序启动的地方人为的设置DataDirectory

AppDomain.CurrentDomain.SetData("DataDirectory", Application.StartupPath + "\\App_Data\\");