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2010-05-26T15:31:19Z

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2010-05-26T11:42:21Z

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==Commit two delete sql command==

<source lang="csharp">
using System;
using System.Data;
using System.Data.SqlClient;
class SqlDemo {
static void Main(){
string connString = "server=(local)\\SQLEXPRESS;database=MyDatabase;Integrated Security=SSPI";
SqlConnection cn = new SqlConnection(connString);
cn.Open();
SqlTransaction objTrans = cn.BeginTransaction();
try{
SqlCommand cmd = cn.CreateCommand();
cmd.rumandType = CommandType.Text;
cmd.Transaction = objTrans;
cmd.rumandText = "DELETE Employee WHERE Id = 222";
cmd.ExecuteNonQuery();
cmd.rumandText="DELETE Employee WHERE Id = 333";
cmd.ExecuteNonQuery();
objTrans.rumit();
Console.WriteLine("Transaction Committed\n");
}
catch (System.Data.SqlClient.SqlException ex)
{
objTrans.Rollback();
Console.WriteLine("Error - TRANSACTION ROLLED BACK\n" + ex.Message);
}
catch (System.Exception ex)
{
Console.WriteLine("System Error\n" + ex.Message);
}
finally
{
cn.Close();
}
}
}

</source>

==illustrates the use of transactions==

<source lang="csharp">
/*
Mastering Visual C# .NET
by Jason Price, Mike Gunderloy
Publisher: Sybex;
ISBN: 0782129110
*/
/*
Example23_4.cs illustrates the use of transactions
*/
using System;
using System.Data;
using System.Data.SqlClient;
public class Example23_4
{
public static void Main()
{
// formulate a string containing the details of the
// database connection
string connectionString =
"server=localhost;database=Northwind;uid=sa;pwd=sa";
// create a SqlConnection object to connect to the
// database, passing the connection string to the constructor
SqlConnection mySqlConnection =
new SqlConnection(connectionString);
// open the database connection using the
// Open() method of the SqlConnection object
mySqlConnection.Open();
// step 1: create a SqlTransaction object and start the transaction
// by calling the BeginTransaction() method of the SqlConnection
// object
SqlTransaction mySqlTransaction =
mySqlConnection.BeginTransaction();
// step 2: create a SqlCommand object to hold a SQL statement
SqlCommand mySqlCommand = mySqlConnection.CreateCommand();
// step 3: set the Transaction property for the SqlCommand object
mySqlCommand.Transaction = mySqlTransaction;
// step 4: formulate a string containing the first INSERT statement
string insertString =
"INSERT INTO Customers (" +
" CustomerID, CompanyName, ContactName, Address" +
") VALUES (" +
" "T2COM", "T2 Company", "Jason Price", "1 Main Street"" +
")";
// step 5: set the CommandText property of the SqlCommand object to
// the INSERT string
mySqlCommand.rumandText = insertString;
// step 6: run the first INSERT statement
Console.WriteLine("Running first INSERT statement");
mySqlCommand.ExecuteNonQuery();
// step 7: formulate a second INSERT statement
insertString =
"INSERT INTO Orders (" +
" CustomerID" +
") VALUES (" +
" "T2COM"" +
")";
// step 8: set the CommandText property of the SqlCommand object to
// the second INSERT string
mySqlCommand.rumandText = insertString;
// step 9: run the second INSERT statement
Console.WriteLine("Running second INSERT statement");
mySqlCommand.ExecuteNonQuery();
// step 10: commit the transaction using the Commit() method
// of the SqlTransaction object
Console.WriteLine("Committing transaction");
mySqlTransaction.rumit();
// close the database connection using the Close() method
// of the SqlConnection object
mySqlConnection.Close();
}
}

</source>

==Set a savepoint in a transaction==

<source lang="csharp">
using System;
using System.Data;
using System.Data.SqlClient;
class Savepoint {
public static void Main() {
SqlConnection mySqlConnection =
new SqlConnection(
"server=localhost;database=Northwind;uid=sa;pwd=sa"
);
mySqlConnection.Open();
SqlTransaction mySqlTransaction = mySqlConnection.BeginTransaction();
SqlCommand mySqlCommand = mySqlConnection.CreateCommand();
mySqlCommand.Transaction = mySqlTransaction;
mySqlCommand.rumandText =
"INSERT INTO Customers ( " +
" CustomerID, CompanyName " +
") VALUES ( " +
" "J8COM", "J8 Company" " +
")";
int numberOfRows = mySqlCommand.ExecuteNonQuery();
Console.WriteLine("Number of rows inserted = " + numberOfRows);
mySqlTransaction.Save("SaveCustomer");
mySqlCommand.rumandText = "INSERT INTO Orders (CustomerID ) VALUES ( "J8COM" )";
numberOfRows = mySqlCommand.ExecuteNonQuery();
Console.WriteLine("Number of rows inserted = " + numberOfRows);
mySqlTransaction.Rollback("SaveCustomer");
mySqlCommand.rumandText =
"SELECT CustomerID, CompanyName " +
"FROM Customers " +
"WHERE CustomerID = "J8COM"";
SqlDataReader mySqlDataReader = mySqlCommand.ExecuteReader();
while (mySqlDataReader.Read()) {
Console.WriteLine("mySqlDataReader[\" CustomerID\"] = " +
mySqlDataReader["CustomerID"]);
Console.WriteLine("mySqlDataReader[\" CompanyName\"] = " +
mySqlDataReader["CompanyName"]);
}
mySqlDataReader.Close();
mySqlCommand.rumandText = "DELETE FROM Customers WHERE CustomerID = "J8COM"";
numberOfRows = mySqlCommand.ExecuteNonQuery();
Console.WriteLine("Number of rows deleted = " + numberOfRows);
mySqlTransaction.rumit();
mySqlConnection.Close();
}
}
</source>

==Transaction roll back and commit==

<source lang="csharp">
using System;
using System.Data;
using System.Data.SqlClient;
class SqlDemo {
static void Main(){
string connString = "server=(local)\\SQLEXPRESS;database=MyDatabase;Integrated Security=SSPI";
SqlConnection cn = new SqlConnection(connString);
cn.Open();
SqlTransaction objTrans = cn.BeginTransaction();
try
{
SqlCommand cmd = cn.CreateCommand();
cmd.rumandType = CommandType.Text;
cmd.Transaction = objTrans;
cmd.rumandText = "DELETE Employee WHERE Id = 222";
cmd.ExecuteNonQuery();
objTrans.rumit();

Console.WriteLine("Transaction Committed\n" );
}
catch (System.Data.SqlClient.SqlException ex)
{
objTrans.Rollback();
Console.WriteLine("Error - TRANSACTION ROLLED BACK\n" + ex.Message);
}
catch (System.Exception ex)
{
Console.WriteLine("System Error\n" + ex.Message);
}
finally
{
cn.Close();
}
}
}

</source>

==Update Data Using Transactions==

<source lang="csharp">
/*
* C# Programmers Pocket Consultant
* Author: Gregory S. MacBeth
* Email: gmacbeth@comporium.net
* Create Date: June 27, 2003
* Last Modified Date:
* Version: 1
*/
using System;
using System.Data;
using System.Data.SqlClient;
namespace Client.Chapter_13___ADO.NET
{
public class UpdatingDataUsingTransactions
{
static void Main(string[] args)
{
SqlConnection MyConnection = new SqlConnection(@"Data Source=(local); Initial Catalog = CaseManager; Integrated Security=true");
MyConnection.Open();
String MyString = "INSERT INTO Test(ID, Contact, Email)VALUES(1, "Greg", "Mac")";
SqlTransaction MyTransaction = MyConnection.BeginTransaction();
SqlCommand MyCmd = new SqlCommand(MyString, MyConnection, MyTransaction);
MyCmd.ExecuteScalar();
MyTransaction.rumit();
MyConnection.Close();
}
}
}

</source>

==Use of a transaction==

<source lang="csharp">
using System;
using System.Data;
using System.Data.SqlClient;
class ExecuteTransaction
{
public static void Main()
{
SqlConnection mySqlConnection =new SqlConnection("server=(local)\\SQLEXPRESS;database=MyDatabase;Integrated Security=SSPI;");
mySqlConnection.Open();
SqlTransaction mySqlTransaction = mySqlConnection.BeginTransaction();
SqlCommand mySqlCommand = mySqlConnection.CreateCommand();
mySqlCommand.Transaction = mySqlTransaction;
mySqlCommand.rumandText =
"INSERT INTO Employee (" +
" ID, FirstName" +
") VALUES (" +
" 10, "Jason"" +
")";
Console.WriteLine("Running first INSERT statement");
mySqlCommand.ExecuteNonQuery();
mySqlCommand.rumandText =
"INSERT INTO Employee (" +
" ID, FirstName" +
") VALUES (" +
" 11, "Jason"" +
")";
Console.WriteLine("Running second INSERT statement");
mySqlCommand.ExecuteNonQuery();
Console.WriteLine("Committing transaction");
mySqlTransaction.rumit();
mySqlConnection.Close();
}
}

</source>

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в 15:31, 26 мая 2010

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