в 15:31, 26 мая 2010

2010-05-26T15:31:53Z

Admin: 1 версия

2010-05-26T12:19:09Z

1 версия

Новая страница

==Delete data using sql statements==

<source lang="csharp">using System;
using System.Data;
using System.Data.SqlClient;
class MainClass
{
static void Main(string[] args)
{
SqlConnection MyConnection = new SqlConnection("server=(local)\\SQLEXPRESS;database=MyDatabase;Integrated Security=SSPI;");
MyConnection.Open();
String MyString = "DELETE Employee";
SqlCommand MyCmd = new SqlCommand(MyString, MyConnection);
MyCmd.ExecuteScalar();
MyConnection.Close();
}
}</source>

==Deleting Data==

<source lang="csharp">using System;
using System.Data;
using System.Data.SqlClient;
using System.Collections.Generic;
using System.Text;
class Program
{
static void Main(string[] args)
{
SqlConnection thisConnection = new SqlConnection(
@"Data Source=.\SQLEXPRESS;" +
@"AttachDbFilename="NORTHWND.MDF";" +
@"Integrated Security=True;Connect Timeout=30;User Instance=true");
SqlDataAdapter thisAdapter = new SqlDataAdapter("SELECT CustomerID, CompanyName FROM Customers", thisConnection);
SqlCommandBuilder thisBuilder = new SqlCommandBuilder(thisAdapter);
DataSet thisDataSet = new DataSet();
thisAdapter.Fill(thisDataSet, "Customers");
Console.WriteLine("# rows before change: {0}",thisDataSet.Tables["Customers"].Rows.Count);
DataColumn[] keys = new DataColumn[1];
keys[0] = thisDataSet.Tables["Customers"].Columns["CustomerID"];
thisDataSet.Tables["Customers"].PrimaryKey = keys;
DataRow findRow = thisDataSet.Tables["Customers"].Rows.Find("1");
findRow.Delete();
int rowsAffected = thisAdapter.Update(thisDataSet, "Customers");
Console.WriteLine("Deleted {0} rows.", rowsAffected);
Console.WriteLine(thisDataSet.Tables["Customers"].Rows.Count);
thisConnection.Close();
}
}</source>

==Execute nonquery to delete a record (row)==

<source lang="csharp">using System;
using System.Data;
using System.Data.SqlClient;
class MainClass
{
static void Main()
{
SqlConnection conn = new SqlConnection("server=(local)\\SQLEXPRESS;database=MyDatabase;Integrated Security=SSPI;");
string sqlqry = @"select count(*) from employee ";
string sqlins = @"insert into employee (firstname,lastname)values("Z", "Z")";
string sqldel = @"delete from employee where firstname = "Z" and lastname = "Z"";
SqlCommand cmdqry = new SqlCommand(sqlqry, conn);
SqlCommand cmdnon = new SqlCommand(sqlins, conn);
try
{
conn.Open();
Console.WriteLine("Before INSERT: Number of employees {0}\n", cmdqry.ExecuteScalar());
Console.WriteLine("Executing statement {0}", cmdnon.rumandText);
cmdnon.ExecuteNonQuery();
Console.WriteLine("After INSERT: Number of employees {0}\n", cmdqry.ExecuteScalar());
cmdnon.rumandText = sqldel;
Console.WriteLine("Executing statement {0}", cmdnon.rumandText);
cmdnon.ExecuteNonQuery();
Console.WriteLine("After DELETE: Number of employees {0}\n", cmdqry.ExecuteScalar());
}
catch (SqlException ex)
{
Console.WriteLine(ex.ToString());
}
finally
{
conn.Close();
Console.WriteLine("Connection Closed.");
}
}
}</source>

← Предыдущая	Версия 15:31, 26 мая 2010
(нет различий)

Csharp/CSharp Tutorial/ADO.Net/SqlCommand Delete - История изменений

в 15:31, 26 мая 2010

Admin: 1 версия