如何用ADO调用SQL数据库；

首先工程然后添加引用public void ConnSQLServer(string ServerName, string DBName){    mCnnDB.ConnectionString = "uid=;pwd= ;driver={SQL Server};" +    "server=" +ServerName+    ";database=" + DBName;    mCnnDB.Open(mCnnDB.ConnectionString,"sa","",-1);}      public void ConnSQLServer(string ServerName, string DBName,string UserID,string UserPwd){   mCnnDB.ConnectionString = "uid='" + UserID + "';pwd='" + UserPwd + "' ;driver={SQL Server};" +    "server=" + ServerName +    ";database=" + DBName;    mCnnDB.Open(mCnnDB.ConnectionString,UserID,UserPwd,-1);;} 
详细参考:http://www.zdnet.com.cn/developer/code/story/0,2000081534,39053250,00.htm