DALmodule and sp transaction
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This document contains information about a mentoring program from Baabtra-Mentoring Partner. It includes weekly targets achieved, jobs applied to, contact information fields, an explanation of data access layers and database transactions, and transaction states. It also includes a procedure for deleting a department from a database and contact information for Baabtra.
DALmodule and sp transaction
- 2. Disclaimer: This presentation is prepared by trainees of baabtra as a part of mentoring program. This is not official document of baabtra –Mentoring Partner Baabtra-Mentoring Partner is the mentoring division of baabte System Technologies Pvt . Ltd
- 3. Week Target Achieved 1 30 27 2 3 Typing Speed
- 4. Jobs Applied # Company Designation Applied Date Current Status 1 2 3
- 5. Database Access Layer Module & Database Transaction Name @gmail.com www.facebook.com/userna me twitter.com/username in.linkedin.com/in/profilena me Phonenumber
- 6. Data Access Layer • A data access layer follows the idea of "separation of concerns“. • DAL consist of the code used to pull data from a db. • Its isolated from business logic layer and presentation layer.
- 8. Why???? DAL • DAL allow us to change more easily the backend physical data storage technology without having large impact on business logic layer. • Data access layers allow us to access data the same way for different application in our program.
- 9. DB Transaction • A transaction is a discrete unit of work that must be completely processed or not processed at all.
- 10. Transaction states • Active, the initial state; the transaction stays in this state until while it is still executing. • A transition is terminated only if it has either been committed or aborted.
- 11. Transaction States • Partially committed, After the final statement has been executed • At this point failure is still possible since changes may have been only done in main memory, a hardware failure could still occur.
- 12. Transaction States • Committed- after successful completion. • Once committed, the transaction can no longer be undone by aborting it. • Its effect could be undone only by a compensating transaction.
- 13. Transaction States • Failed, after the discovery that normal execution can no longer proceed. • Once a transaction can not be completed, any changes that it made must be undone rolling it back.
- 14. Transaction States • Aborted, after the transaction has been rolled back the database has been restored to its state prior to the start of the transaction. • The DBMS could either kill the transaction or restart the transaction.
- 15. Create procedure DeleteDepartment ( @DepartmentID int ) AS BEGIN TRANSACTION DELETE FROM Employees WHERE DepartmentID = @DepartmentID IF @@ERROR <> 0 BEGIN ROLLBACK RAISERROR ('Error in deleting employees in DeleteDepartment.', 16, 1) RETURN END DELETE FROM Departments WHERE DepartmentID = @DepartmentID IF @@ERROR <> 0 BEGIN ROLLBACK RAISERROR ('Error in deleting department in DeleteDepartment.', 16, 1) RETURN END COMMIT
- 16. If this presentation helped you, please visit our page facebook.com/baabtra and like it. Thanks in advance. www.baabtra.com | www.massbaab.com |www.baabte.com
- 17. Contact Us Emarald Mall (Big Bazar Building) Mavoor Road, Kozhikode, Kerala, India. Ph: + 91 – 495 40 25 550 NC Complex, Near Bus Stand Mukkam, Kozhikode, Kerala, India. Ph: + 91 – 495 40 25 550 Start up Village Eranakulam, Kerala, India. Email: info@baabtra.com