using System;
using System.Data;
using System.Configuration;
using System.Linq;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.HtmlControls;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Data;
using System.Data.SqlClient;
namespace test
{
public class Class1
{
public DataSet RunQuery(String QueryString)
{
String ConnectionString = "server=localhost;database=NorthWind;Integrated Security=SSPI";
try
{
using (SqlConnection DBConnection = new SqlConnection(ConnectionString))
{
DBConnection.Open();
DataSet ResultsDataSet = new DataSet();
SqlDataAdapter DBAdapter = new SqlDataAdapter(QueryString, DBConnection);
DBAdapter.Fill(ResultsDataSet);
}
}
catch (Exception ex)
{
ex.Message;
}
return ResultsDataSet;
}
}
}
string sql = "select * from users ";
string stringconcetion = System.Configuration.ConfigurationManager.ConnectionStrings["Conn"].ConnectionString;
using (SqlConnection conn = new SqlConnection(stringconcetion))
{
conn.Open();
SqlCommand cmd = new SqlCommand(sql,conn);
string LastTime = cmd.ExecuteScalar().Tostring();
}
String ConnectionString = "server=localhost;database=NorthWind;Integrated Security=SSPI";
string sql="select * from users";
using (SqlConnection cn = new SqlConnection(ConnectionString ))
{
SqlCommand command=new SqlCommand(sql,cn);
cn.Open()
//SqlDataReader 对象中保存查询的结果，不能new。相当于游标，先打开 再读取 最后关闭。
SqlDataReader reader=command.ExecuteReader(CommandBehavior.CloseConnection); //CloseConnection 指定在关闭DataReader的时候，自动关闭数据库连接。
while (reader.Read())
{
//int id=(int)reader[0]; 第二种写法
//int id=reader.GetInt(0); 第三种写法
int id=(int)reader["userid"];
}
reader.Close();
}
