Csharp/C Sharp/Database ADO.net/Transactions — различия между версиями

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Текущая версия на 11:42, 26 мая 2010

Commit two delete sql command

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();  
         }
      }
   }


illustrates the use of transactions

/*
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();
  }
}


Set a savepoint in a transaction

 
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();
    }
}


Transaction roll back and commit

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();
         }
      }
   }


Update Data Using Transactions

/*
 * 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();
        }
    }
}


Use of a transaction

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();
  }
}