从数据库中删除数据
// 从数据库中删除数据
// DelCmd.cs
using System;
using System.Data;
using System.Data.SqlClient;
namespace Ch13
{
class DelCmd
{
static void Main( string[] args)
{
string strConn = "server=.\\MSSQL2012;integrated security=true;database=Northwind";
string qry = "select * from employees where employeeid>8" ;
string del = "delete from employees where employeeid=@empid";
SqlConnection conn = new SqlConnection(strConn);
try
{
SqlDataAdapter da = new SqlDataAdapter();
da.SelectCommand = new SqlCommand(qry, conn);
DataSet ds = new DataSet();
da.Fill(ds, "emp");
DataTable dt = ds.Tables[ "emp"];
Console.WriteLine( "删除前");
foreach (DataRow row in dt.Rows)
{
Console.WriteLine( "{0} {1} {2} {3}"
, row[ "employeeid"].ToString().PadRight(5)
, row[ "firstname"].ToString().PadRight(15)
, row[ "lastname"].ToString().PadRight(15)
, row[ "city"]);
}
SqlCommand cmd = new SqlCommand(del, conn);
cmd.Parameters.Add( "@empid", SqlDbType.Int, 4, "employeeid");
string filter = "firstname='张' and lastname='三'" ;
foreach (DataRow row in dt.Select(filter))
{
row.Delete();
}
da.DeleteCommand = cmd;
da.Update(ds, "emp");
Console.WriteLine( "删除后");
foreach (DataRow row in dt.Rows)
{
Console.WriteLine( "{0} {1} {2} {3}"
, row[ "employeeid"].ToString().PadRight(5)
, row[ "firstname"].ToString().PadRight(15)
, row[ "lastname"].ToString().PadRight(15)
, row[ "city"]);
}
}
catch( Exception ex)
{
Console.WriteLine( "出错了:" + ex);
}
finally
{
conn.Close();
Console.ReadLine();
}
}
}
}
-------------
删除前
9 Anne Dodsworth London
15 张 三 深圳
删除后
9 Anne Dodsworth London
