Easy-to-follow video tutorials help you learn software, creative, and business skills.Become a member

Implementing logging on DELETE

From: SQL Server: Triggers, Stored Procedures, and Functions

Video: Implementing logging on DELETE

For our DELETE stored procedure, the rules we're going to implement is the stored procedure can only delete one record at a time, and we must maintain a log of who deleted and when. So in order to maintain that log I'd like to create a new table that will be used for that logging. I have some code staged for that. It's a three column table; one column for user name, the person who did the deletion, one column for the ID that they deleted, and one column for the date. I also have some codes staged for the stored procedure. So starting at the top we have with CREATE PROCEDURE Students_Delete.

Implementing logging on DELETE

For our DELETE stored procedure, the rules we're going to implement is the stored procedure can only delete one record at a time, and we must maintain a log of who deleted and when. So in order to maintain that log I'd like to create a new table that will be used for that logging. I have some code staged for that. It's a three column table; one column for user name, the person who did the deletion, one column for the ID that they deleted, and one column for the date. I also have some codes staged for the stored procedure. So starting at the top we have with CREATE PROCEDURE Students_Delete.

This time we are only taking one parameter. All I need is the ID of what you would like to delete. Line number 2 there is new to us. We're saying EXCUTE AS CALLER. There are some context in which a stored procedure might execute as the system, but in this one, one of my business requirements is to log who is running this. So I am going to specifically saying EXCUTE AS CALLER. Line 6 through 11 we check to make sure that this ID already exists and make sure it only exists in the database once. Now we did something very similar to this in the INSERT stored procedure, and the UPDATE stored procedure.

Now we're going to have it a third time in the DELETE stored procedure. This is becoming a little displeasing to me to have an essentially the exact same code running in three different places. So I'm going to use a technique we talked about earlier in this course of simplifying our lives. I am going to create a function that performs all of this and that way we'll just be able to use the function. We won't have to maintain the exact same code in three different places. So we'll take a slight detour and I'll pull up the code I had for the function. So this is a function that is going to count the number of times that a certain ID exists in our students table.

The only parameter you have to pass to it is an ID. The ID you're in fact looking for. It'll return an integer, a single integer saying how may times does this ID occur. Execute that, command(s) completed successfully. That's good news. So now I'll go back to the stored procedure and replace that code. This code that appears in three different places. I want to simplify my life and get rid all that. All I need to check on is the value of this. So that code will pass the ID in question to the function called Count IDs, and that function will return the number of times that ID occurs in our table.

Beyond that, things are fairly straightforward. Line 50 and 16 will perform the delete. Line 20 checks to see if we did in fact delete exactly 1 record, and if we did we need to meet our other business requirements of logging who did the deletion. So line 22 and 23 will insert a new record into Student_Delete log. The values we are looking for is suser_ sname which is a SQL Server variable that stores the name of who is running the stored procedure. The next thing we pass to it is the ID that was deleted, and the last thing we pass is the current date.

Let's go ahead and run that and that gives us one stored procedure for deleting a student, one stored procedure for inserting a student, and one for updating a student. We have nice a little package of all of the things we're likely to perform on a student. Go ahead and test the delete functionality. It says one row affected so that should have deleted that ID from the student table, and yes, in fact that record is gone.

We also said we we're going to log this. So let's check to make sure our log is functioning properly, and we see one record in there, User Name Martin, deleted the ID 123456. There is the date the record was deleted. So we have successfully implemented all of the business rules for a DELETE stored procedure.

Show transcript

This video is part of

Image for SQL Server: Triggers, Stored Procedures, and Functions
 
Expand all | Collapse all
  1. 2m 15s
    1. Welcome
      51s
    2. What you should know
      51s
    3. Using the exercise files
      33s
  2. 11m 1s
    1. Comparing triggers, functions, and procedures
      3m 25s
    2. Why use a stored procedure?
      4m 59s
    3. Why use functions?
      1m 27s
    4. Why use triggers?
      1m 10s
  3. 6m 2s
    1. Configuring your environment
      4m 53s
    2. Downloading and installing a sample database
      1m 9s
  4. 26m 25s
    1. Creating a stored procedure
      2m 46s
    2. Modifying a stored procedure
      2m 34s
    3. Returning data using data sets
      3m 45s
    4. Returning data using cursors
      3m 45s
    5. Using input and output parameters
      5m 24s
    6. Using security and permissions
      5m 24s
    7. Using transactions
      2m 47s
  5. 11m 56s
    1. Creating a user-defined function
      4m 59s
    2. Exploring single-value functions
      4m 18s
    3. Exploring table value functions
      2m 39s
  6. 9m 31s
    1. Using "after" triggers
      3m 47s
    2. Using "instead of" triggers
      2m 9s
    3. Using nested triggers
      1m 38s
    4. Using database-level triggers
      1m 57s
  7. 12m 43s
    1. Exploring a real-world INSERT procedure
      5m 32s
    2. Exploring a real-world UPDATE procedure
      3m 13s
    3. Implementing logging on DELETE
      3m 58s
  8. 19m 38s
    1. Understanding the Common Language Runtime (CLR) and the .NET framework
      1m 52s
    2. Using CLR with SQL Server 2012
      4m 11s
    3. Writing stored procedures with C# .NET
      5m 51s
    4. Writing functions with .NET
      5m 7s
    5. Choosing between T-SQL vs. CLR
      2m 37s
  9. 11m 34s
    1. Creating a basic web form and connecting to a database
      2m 56s
    2. Executing a stored procedure
      2m 4s
    3. Passing parameters
      3m 41s
    4. Getting return values
      2m 53s
  10. 1m 43s
    1. Next steps
      1m 43s

Start learning today

Get unlimited access to all courses for just $25/month.

Become a member
Sometimes @lynda teaches me how to use a program and sometimes Lynda.com changes my life forever. @JosefShutter
@lynda lynda.com is an absolute life saver when it comes to learning todays software. Definitely recommend it! #higherlearning @Michael_Caraway
@lynda The best thing online! Your database of courses is great! To the mark and very helpful. Thanks! @ru22more
Got to create something yesterday I never thought I could do. #thanks @lynda @Ngventurella
I really do love @lynda as a learning platform. Never stop learning and developing, it’s probably our greatest gift as a species! @soundslikedavid
@lynda just subscribed to lynda.com all I can say its brilliant join now trust me @ButchSamurai
@lynda is an awesome resource. The membership is priceless if you take advantage of it. @diabetic_techie
One of the best decision I made this year. Buy a 1yr subscription to @lynda @cybercaptive
guys lynda.com (@lynda) is the best. So far I’ve learned Java, principles of OO programming, and now learning about MS project @lucasmitchell
Signed back up to @lynda dot com. I’ve missed it!! Proper geeking out right now! #timetolearn #geek @JayGodbold
Share a link to this course

What are exercise files?

Exercise files are the same files the author uses in the course. Save time by downloading the author's files instead of setting up your own files, and learn by following along with the instructor.

Can I take this course without the exercise files?

Yes! If you decide you would like the exercise files later, you can upgrade to a premium account any time.

Become a member Download sample files See plans and pricing

Please wait... please wait ...
Upgrade to get access to exercise files.

Exercise files video

How to use exercise files.

Learn by watching, listening, and doing, Exercise files are the same files the author uses in the course, so you can download them and follow along Premium memberships include access to all exercise files in the library.


Exercise files

Exercise files video

How to use exercise files.

For additional information on downloading and using exercise files, watch our instructional video or read the instructions in the FAQ.

This course includes free exercise files, so you can practice while you watch the course. To access all the exercise files in our library, become a Premium Member.

Are you sure you want to mark all the videos in this course as unwatched?

This will not affect your course history, your reports, or your certificates of completion for this course.


Mark all as unwatched Cancel

Congratulations

You have completed SQL Server: Triggers, Stored Procedures, and Functions.

Return to your organization's learning portal to continue training, or close this page.


OK
Become a member to add this course to a playlist

Join today and get unlimited access to the entire library of video courses—and create as many playlists as you like.

Get started

Already a member?

Become a member to like this course.

Join today and get unlimited access to the entire library of video courses.

Get started

Already a member?

Exercise files

Learn by watching, listening, and doing! Exercise files are the same files the author uses in the course, so you can download them and follow along. Exercise files are available with all Premium memberships. Learn more

Get started

Already a Premium member?

Exercise files video

How to use exercise files.

Ask a question

Thanks for contacting us.
You’ll hear from our Customer Service team within 24 hours.

Please enter the text shown below:

The classic layout automatically defaults to the latest Flash Player.

To choose a different player, hold the cursor over your name at the top right of any lynda.com page and choose Site preferencesfrom the dropdown menu.

Continue to classic layout Stay on new layout
Exercise files

Access exercise files from a button right under the course name.

Mark videos as unwatched

Remove icons showing you already watched videos if you want to start over.

Control your viewing experience

Make the video wide, narrow, full-screen, or pop the player out of the page into its own window.

Interactive transcripts

Click on text in the transcript to jump to that spot in the video. As the video plays, the relevant spot in the transcript will be highlighted.

Are you sure you want to delete this note?

No

Your file was successfully uploaded.

Thanks for signing up.

We’ll send you a confirmation email shortly.


Sign up and receive emails about lynda.com and our online training library:

Here’s our privacy policy with more details about how we handle your information.

Keep up with news, tips, and latest courses with emails from lynda.com.

Sign up and receive emails about lynda.com and our online training library:

Here’s our privacy policy with more details about how we handle your information.

   
submit Lightbox submit clicked
Terms and conditions of use

We've updated our terms and conditions (now called terms of service).Go
Review and accept our updated terms of service.