C#连接常用数据库的DBProviderName配置

　　　　为了适应应对各种数据库间切换，我们有时想要要自定义写一个通用的SqlHelper。常用的做法就是在 System.Data.Common.DbProviderFactories.GetFactory(dbProviderName).CreateConnection() ，来返回对应的 数据库的Connection 。

直接上测试源码：

            string dbProviderName = "System.Data.Odbc";
            dbProviderName = "System.Data.OleDb";
            dbProviderName = "System.Data.SqlClient";
            dbProviderName = "System.Data.OracleClient";

            //引用 System.Data.SQLite.dll
            dbProviderName = "System.Data.SQLite";

            //引用 MySql.Data.dll
            dbProviderName = "MySql.Data.MySqlClient";

            //引用 Oracle.ManagedDataAccess.dll
            dbProviderName = "Oracle.ManagedDataAccess.Client";

            DbProviderFactory dbfactory = DbProviderFactories.GetFactory(dbProviderName);
            DbConnection dbconn = dbfactory.CreateConnection();

            dbconn.ConnectionString = string.Empty;// 数据库连接字符串

　　　　需要注意的 config 配置：

<?xml version="1.0" encoding="utf-8"?>
<configuration>
  <startup useLegacyV2RuntimeActivationPolicy="true">
    <supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.0"/>
    <supportedRuntime version="v2.0.50727"/>
  </startup>
<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="MySql.Data.MySqlClient"/>
      <add name="MySQL Data Provider" invariant="MySql.Data.MySqlClient" description=".Net Framework Data Provider for MySQL" type="MySql.Data.MySqlClient.MySqlClientFactory, MySql.Data" />

      <remove invariant="Oracle.ManagedDataAccess.Client"/>
      <add name="Oracle Data Provider" invariant="Oracle.ManagedDataAccess.Client" description="Oracle Data Provider for .NET" type="Oracle.ManagedDataAccess.Client.OracleClientFactory, Oracle.ManagedDataAccess" />    

    </DbProviderFactories>

  </system.data>
</configuration>

　　　　最后附上 代码。