C#中的SqlHelper

矫情吗；* 2021-06-24 15:59 417阅读 0赞

一直都在使用的SqlHelper究竟是什么呢，其实就是将需要连接数据库的部分封装成为了一个SqlHelper

但是只会用还不行，还要将SqlHelper手敲出来，没有源码也要会敲，所以我就多敲了几遍来加深记忆，当然最重要的是你要理解之后才行！

注释回头再加，见谅

代码如下：

public  class SqlHelper
        {
            public static readonly string ConnStr = "server=.;Database=Session1;User ID=sa;Password=123456";
            private SqlCommand cmd = null;
            private SqlConnection conn = new SqlConnection(ConnStr);
            private SqlDataReader sdr = null;
    
            private SqlConnection Getconn()
            {
                if (conn.State == ConnectionState.Closed)
                {
                    conn.Open();
                }
                return conn;
            }
    
            public int ExecuteNonQuery(String cmdText, CommandType ct)
            {
                int res;
                cmd = new SqlCommand(cmdText, Getconn());
                cmd.CommandType = ct;
                res = cmd.ExecuteNonQuery();
                return res;
            }
            public int ExecuteNonQuery(string cmdText,CommandType ct,SqlParameter[] sqlparas)
            {
                int res;
                cmd = new SqlCommand(cmdText, Getconn());
                cmd.Parameters.AddRange(sqlparas);
                cmd.CommandType = ct;
                res = cmd.ExecuteNonQuery();
                conn.Close();
                return res;
            }
    
            public DataTable ExecuteQuery(string cmdText, CommandType ct)
            {
                DataTable dt = new DataTable();
                cmd = new SqlCommand(cmdText, Getconn());
                cmd.CommandType = ct;
                using (sdr = cmd.ExecuteReader(CommandBehavior.CloseConnection))
                {
                    dt.Load(sdr);
                }
                return dt;
            }
            public DataTable ExecuteQuery(string cmdText, CommandType ct,SqlParameter[] sqlparas)
            {
                DataTable dt = new DataTable();
                cmd.CommandType = ct;
                cmd = new SqlCommand(cmdText, Getconn());
                cmd.Parameters.AddRange(sqlparas);//和不带SqlParameter的方法就差这一行
                using (sdr = cmd.ExecuteReader(CommandBehavior.CloseConnection))
                {
                    dt.Load(sdr);
                }
                return dt;
            }
    
    
    
    
        }