如何基于提供程序名称构造一个DbConnection?
示例提供程序名称
- System.Data.SqlClient
- System.Data.OleDb
- System.Data.Odbc
- FirebirdSql.Data.FirebirdClient
我在IIS服务器的web.config文件中存储了连接字符串:
<connectionStrings>
<add name="development"
connectionString="Provider = IBMDA400; Data Source = MY_SYSTEM_NAME; User Id = myUsername; Password = myPassword;"
providerName="System.Data.OleDb" />
<add name="live"
connectionString="usd=sa;pwd=password;server=deathstar;"
providerName="System.Data.Odbc" />
<add name="testing"
connectionString="usd=sa;pwd=password;server=deathstar;"
providerName="System.Data.SqlClient" />
<add name="offline"
connectionString="Server=localhost;User=SYSDBA;Password=masterkey;Charser=NONE;Database=c:\data\mydb.fdb"
providerName="FirebirdSql.Data.FirebirdClient"/>
你可以看到它们都使用不同的提供程序。当我创建连接时,我必须知道要创建哪种 DbConnection
,例如:
SqlConnection
OleDbConnection
OdbcConnection
FbConnection
connectionStrings
条目包含一个 providerName,但这些不是 DbConnection
子类的名称,而似乎是一个命名空间。
如何基于 providerName 字符串构造一个 DbConnection
?
public DbConnection GetConnection(String connectionName)
{
//Get the connectionString infomation
ConnectionStringSettings cs =
ConfigurationManager.ConnectionStrings[connectionName];
if (cs == null)
throw new ConfigurationException("Invalid connection name \""+connectionName+"\");
//Create a connection based on the provider
DbConnection conn = new DbConnection();
}