public abstract class SQLHelper 
   { 
     ///  <summary> 
     /// 连接字符串 
     ///  </summary> 
  
    public static readonly string ConnectionString = "数据库连接字符串"; 
  
     
     
        
     private static Hashtable parmCache = Hashtable.Synchronized(new Hashtable()); 
  
     ///  <summary> 
     /// 数据库增,删,改方法 
     ///  </summary> 
     ///  <param name="connectionString">连接字符串 </param> 
     ///  <param name="cmdType">Command类型 </param> 
     ///  <param name="cmdText">执行文本 </param> 
     ///  <param name="commandParameters">参数 </param> 
     ///  <returns> </returns> 
     public static int ExecuteNonQuery(string connectionString, CommandType cmdType, string cmdText, params SqlParameter[] commandParameters) 
     { 
  
       SqlCommand cmd = new SqlCommand(); 
        
       using (SqlConnection conn = new SqlConnection(connectionString)) 
       { 
         PrepareCommand(cmd, conn, null, cmdType, cmdText, commandParameters); 
         int val = cmd.ExecuteNonQuery(); 
         cmd.Parameters.Clear(); 
         return val; 
       } 
     } 
  
     ///  <summary>a 
     /// 数据库增,删,改方法 
  
     ///  </summary> 
     ///  <param name="connection">连接对象 </param> 
     ///  <param name="cmdType">Command类型 </param> 
     ///  <param name="cmdText">执行文本 </param> 
     ///  <param name="commandParameters">参数 </param> 
     ///  <returns> </returns> 
     public static int ExecuteNonQuery(SqlConnection connection, CommandType cmdType, string cmdText, params SqlParameter[] commandParameters) 
     { 
  
       SqlCommand cmd = new SqlCommand(); 
  
       PrepareCommand(cmd, connection, null, cmdType, cmdText, commandParameters); 
       int val = cmd.ExecuteNonQuery(); 
       cmd.Parameters.Clear(); 
       return val; 
     } 
  
     ///  <summary> 
     /// 数据库增,删,改方法 
  
     ///  </summary> 
     ///  <param name="trans">事务 </param> 
     ///  <param name="cmdType">Command类型 </param> 
     ///  <param name="cmdText">执行文本 </param> 
     ///  <param name="commandParameters">参数 </param> 
     ///  <returns> </returns> 
     public static int ExecuteNonQuery(SqlTransaction trans, CommandType cmdType, string cmdText, params SqlParameter[] commandParameters) 
     { 
       SqlCommand cmd = new SqlCommand(); 
       PrepareCommand(cmd, trans.Connection, trans, cmdType, cmdText, commandParameters); 
       int val = cmd.ExecuteNonQuery();