sqlcommand对象的使用方法总结

来源：互联网发布：c#数组添加数据编辑：程序博客网时间：2024/05/07 06:15

总结了一下,在任何时候都可以使用sqlcommand对象来完成您想要的操作.
使用sqlcommand对象来返回数据集合的方法
string strconn="data source=billgates;initial catalog=test;integrated security=SSPI;";
SqlConnection conn=new SqlConnection(strconn);
conn.Open();SqlCommand sqlcmd=new SqlCommand();
sqlcmd.CommandText ="select * from student";
sqlcmd.Connection=conn;SqlDataAdapter adp=new SqlDataAdapter(sqlcmd);
DataTable dt=new DataTable();
adp.Fill(dt);
dataGrid1.DataSource=dt;使用sqlcommand对象来返回SQL执行正确与否string strconn="data source=billgates;initial catalog=test;integrated security=SSPI;";
SqlConnection conn=new SqlConnection(strconn);
conn.Open();SqlCommand sqlcmd=new SqlCommand();
sqlcmd.CommandText ="select * from student";
sqlcmd.Connection=conn;
try
{
sqlcmd.ExecuteNonQuery();
MessageBox.Show("success");
}
catch
{
MessageBox.Show("false");
}使用sqlcommand对象来操作存储过程string strconn="data source=billgates;initial catalog=test;integrated security=SSPI;";
SqlConnection conn=new SqlConnection(strconn);
conn.Open();SqlCommand sqlcmd=new SqlCommand();
sqlcmd.CommandText ="a";
sqlcmd.CommandType=CommandType.StoredProcedure ;
sqlcmd.Connection=conn;
sqlcmd.Parameters.Add("@param1",textBox1.Text.Trim());
sqlcmd.Parameters.Add("@param2",textBox2.Text.Trim());
sqlcmd.Parameters.Add("@param3",textBox3.Text.Trim());

SqlDataAdapter adp=new SqlDataAdapter(sqlcmd);
DataTable dt=new DataTable();
adp.Fill(dt);
dataGrid1.DataSource=dt;

ExecuteReader

using System;
using System.Data.SqlClient;
public class Lvcha
{
public static void Main(string[] args)
{
   string source="Server =192.168.1.100; User ID=ac_sy_guest; Password=guest1314; Initial CataLog=Account";
   string select="select * from dbUser";
   SqlConnection conn=new SqlConnection(source);
   conn.Open();
   SqlCommand cmd=new SqlCommand(select,conn);
   SqlDataReader reader=cmd.ExecuteReader();//返回只能读取,不能写入的SqlDataReader对象
   while(reader.Read())
   {
    Console.WriteLine("{0}",reader["user_name"]);
   }
   Console.ReadLine();
}
}

ExecuteNonQuery

一般修改删除都插入都用它

返回受影响的行数。

using System;
using System.Data.SqlClient;
public class Lvcha
{
public static void Main(string[] args)
{
   string source="Server =192.168.1.100; User ID=ac_sy_guest; Password=guest1314; Initial CataLog=Account";
   string select="updata .....";
   SqlConnection conn=new SqlConnection(source);
   conn.Open();
   SqlCommand cmd=new SqlCommand(select,conn);
   object o=cmd.ExecuteNonQuery();

   while(reader.Read())
   {
   Console.WriteLine("{0}",reader["user_name"]);
   }
   Console.ReadLine();
}
}
SqlCommand类的ExecuteScalar方法

执行查询，并返回查询所返回的结果集中第一行的第一列。所有其他的列和行将被忽略。

using System;
using System.Data.SqlClient;
public class Lvcha
{
public static void Main(string[] args)
{
   string source="Server =192.168.1.100; User ID=ac_sy_guest; Password=guest1314; Initial CataLog=Account";
   string select="select count(*) from dbUser";
   SqlConnection conn=new SqlConnection(source);
   conn.Open();
   SqlCommand cmd=new SqlCommand(select,conn);
   object o=cmd.ExecuteScalar();
   Console.WriteLine(o);
   Console.ReadLine();
}