版权声明:本文为Banana原创文章,未经Banana允许不得转载。评论请留下你认真观看后的想法或者意见,非常感谢! https://blog.csdn.net/qq1515312832/article/details/79781669
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;
}
}