Autocommit Transactions in VS .NET

Generator DataMatrix in VS .NET Autocommit Transactions

Autocommit Transactions
ECC200 Scanner In VS .NET
Using Barcode Control SDK for Visual Studio .NET Control to generate, create, read, scan barcode image in Visual Studio .NET applications.
Paint Data Matrix ECC200 In .NET Framework
Using Barcode generator for VS .NET Control to generate, create ECC200 image in VS .NET applications.
In fact, every Transact-SQL statement is a transaction. When it is executed, it either finishes successfully or is completely abandoned. To illustrate this, let s try to delete all records from the EqType table. Take a look at the following diagram:
Data Matrix ECC200 Reader In VS .NET
Using Barcode recognizer for VS .NET Control to read, scan read, scan image in VS .NET applications.
Barcode Drawer In VS .NET
Using Barcode creator for .NET Control to generate, create barcode image in Visual Studio .NET applications.
A foreign key relationship exists between the EqType and Equipment tables. The foreign key prevents the deletion of records in the EqType table that are referenced by records in the Equipment table. Let s try to delete them anyway. You can see the result of such an attempt in Figure 6-2. Two Select statements that will count the number of records in EqType are placed around the Delete statement. As expected, the Delete statement is aborted because of the foreign key. The count of records before and after the Delete statement is the same, which confirms that all changes made by the Delete statement were canceled. So the database remains in the state that it was in before the change was initiated. If there were no errors, SQL Server would automatically commit the transaction (that is, it would record all changes) to the database. This kind of behavior is called autocommit. In this case, SQL Server deleted records one after the other from the EqType table until it encountered a record that could not be deleted because of the foreign key relationship, at which point the operation was canceled.
Bar Code Scanner In .NET
Using Barcode decoder for .NET framework Control to read, scan read, scan image in Visual Studio .NET applications.
Make Data Matrix ECC200 In C#.NET
Using Barcode drawer for VS .NET Control to generate, create Data Matrix 2d barcode image in VS .NET applications.
SQL Server 2000 Stored Procedure & XML Programming
Draw Data Matrix ECC200 In VS .NET
Using Barcode creation for ASP.NET Control to generate, create Data Matrix 2d barcode image in ASP.NET applications.
Print DataMatrix In Visual Basic .NET
Using Barcode generation for .NET framework Control to generate, create Data Matrix image in .NET framework applications.
Figure 6-2
Bar Code Creation In .NET Framework
Using Barcode generator for .NET framework Control to generate, create bar code image in VS .NET applications.
Encode DataMatrix In Visual Studio .NET
Using Barcode encoder for Visual Studio .NET Control to generate, create Data Matrix ECC200 image in .NET applications.
Complete failure of attempt to delete records
Code 128 Creator In VS .NET
Using Barcode creation for VS .NET Control to generate, create Code 128C image in .NET applications.
Draw OneCode In .NET
Using Barcode printer for .NET framework Control to generate, create 4-State Customer Barcode image in VS .NET applications.
Explicit Transactions
Drawing EAN / UCC - 13 In None
Using Barcode maker for Microsoft Word Control to generate, create UCC.EAN - 128 image in Microsoft Word applications.
Code 39 Generator In VS .NET
Using Barcode creator for Reporting Service Control to generate, create Code-39 image in Reporting Service applications.
The most popular and obvious way to use transactions is to give explicit commands to start or finish the transaction. Transactions started in this way are called explicit transactions. You can group Transact-SQL statements into a single transaction using the following statements: Begin Transaction Rollback Transaction Commit Transaction If anything goes wrong with any of the grouped statements, all changes need to be aborted. The process of reversing changes is called rollback in SQL Server terminology. If everything is in order with all statements within a single transaction, all changes are recorded together in the database. In SQL Server terminology, these changes are committed to the database.
Scan Code 39 Full ASCII In C#
Using Barcode reader for .NET Control to read, scan read, scan image in Visual Studio .NET applications.
UCC-128 Maker In Visual C#.NET
Using Barcode printer for Visual Studio .NET Control to generate, create GTIN - 128 image in .NET framework applications.
C h a p t e r 6 : C o m p o s i t e Tr a n s a c t - S Q L C o n s t r u c t s : B a t c h e s , S c r i p t s , a n d Tr a n s a c t i o n s
Bar Code Generation In Java
Using Barcode maker for BIRT Control to generate, create barcode image in BIRT applications.
Create ANSI/AIM Code 39 In Objective-C
Using Barcode creation for iPhone Control to generate, create Code 3 of 9 image in iPhone applications.
I will demonstrate the use of these processes on the prClearLeaseSchedule stored procedure. Its main purpose is to set monthly lease amounts to zero for each asset associated with an expired lease schedule. It also sets the total of the lease amounts to zero. These two operations must be performed simultaneously to preserve the integrity of the database.
Paint UPC - 13 In Java
Using Barcode maker for Java Control to generate, create EAN-13 image in Java applications.
UPC-A Reader In None
Using Barcode decoder for Software Control to read, scan read, scan image in Software applications.
Create Procedure prClearLeaseShedule -- Set value of Lease of all equipment -- associated with expired Lease Schedule to 0. -- Set total amount of Lease Schedule to 0. @intLeaseScheduleId int As Begin Transaction -- Set value of Lease of all equipment -- associated with expired Lease Schedule to 0 Update Inventory Set Lease = 0 Where LeaseScheduleId = @intLeaseScheduleId If @@Error <> 0 goto PROBLEM -- Set total amount of Lease Schedule to 0 Update LeaseSchedule Set PeriodicTotalAmount = 0 Where ScheduleId = @intLeaseScheduleId If @@Error <> 0 goto PROBLEM Commit Transaction Return 0 PROBLEM: Print ' Unable to eliminate lease amounts from the database!' Rollback Transaction Return 1
Before the real processing starts, the Begin Transaction statement notifies SQL Server to treat all of the following actions as a single transaction. It is followed by two Update statements. If no errors occur during the updates, all changes are committed to the database when SQL Server processes the Commit Transaction statement, and finally the stored procedure finishes. If an error occurs during the
Copyright © OnBarcode.com . All rights reserved.