Comments on: How To Use Triggers to Track Changes in MySQL

By: Denis Pujdak

Denis Pujdak — Sat, 25 Jun 2011 16:54:04 +0000

It is possible to use Checksum MySQL http://adm-it.net/checksum-mys...

By: Rick

Rick — Fri, 01 Apr 2011 14:56:22 +0000

As a bit of a follow up…. I guess the way that it is currently set up it would insert two times into the history_clients table if your UPDATE contained a change to the first AND last name. Maybe there is a reason for doing this, but I would think that reflecting BOTH changes in one row in the history_clients table would be the way to go. That is why I am wondering if we could somehow combine them.

By: Rick

Rick — Fri, 01 Apr 2011 14:40:06 +0000

Hello,

I am wondering if there is a way to combine the 2 if statements in the MySQL trigger. Instead of having one to check and see if there has been a change to the first name and a SEPARATE check to see if there has been a change to the last name would it be possible to combine them?

I guess what I am asking is if MySQL can support a structure such as IF( A != B || C != D){... If "a" or "b" is the following... or even an IF (A != B && C != D){... If "a" and "b" do the following.

Thanks in advance,
Rick

By: how to get pregnant fast

how to get pregnant fast — Thu, 03 Feb 2011 05:40:29 +0000

Thanks for sharing your mind with us.

By: Ana30soberano

Ana30soberano — Sat, 23 Oct 2010 03:29:01 +0000

-using phpmyadmin actuly im using xampplite wuold u help me?

By: Ana30soberano

Ana30soberano — Sat, 23 Oct 2010 03:27:57 +0000

-hai would u,,,create simple log in,,that if the username is wrong…then,,,the echo wuold be wrong pass and username?

By: Ali

Ali — Sat, 01 May 2010 16:37:18 +0000

great to have found this site. I have used all search engines to find someone trying to update a table based on input changes. My issue was:
1- keep loading a table everyday.
2- data rows that is to load the table are repetitive. Not all of them change in value
3- once i use insert .... on duplicate key update . The table updates with the new information irrespective whether the values are equal or not. I am not sure why, but I have a timestamp field among the fields. And, i am passing a current_timestamp() function in the insert statement. This is needed to timestamp new records, and timestamp the duplicate key records if any of their values differ.
What I ended up getting, an updated timestamp that is always current. I lose track whether a real change exist in the values themselves. I think timestamp fields update with a timestamp irrespective whether other values change, that's because the timestamp field by itself changed. Enough to execute the update. This is the first caveat. What I really want is to leave the row unchanged based on the values i am checking and reset the timestamp to the old one.
so, the trigger helped me achieve that by putting an if then else statement. Similar to the above, yet introduced the else and SET new.timestamp = old.timestamp, new.counter=old.counter. My if checks all the values that might have changes with
IF NEW.VALUE<>OLD.VALUE OR NEW.VALUE_1 <> OLD.VALUE_1 for all values ...,
THEN INSERT INTO history_table SELECT * FROM table WHERE identifiers are =..
(The OLD.* didn't work.)
ELSE SET NEW.TIMESTAMP=OLD.TIMESTAMP, NEW.COUNTER=OLD.COUNTER

That did the magic, because it neutralized the new buffer to the old buffer and the update needn't to execute.

Hope that helps those who have the same issue.

By: Anthony

Anthony — Fri, 22 Jan 2010 10:58:24 +0000

perfect… exactly what I was looking for.

By: Phani Kumar Varanasi

Phani Kumar Varanasi — Thu, 12 Nov 2009 04:24:16 +0000

Yeah Dear, the concept you entered is so helpful, well good work.

By: abhinavzone

abhinavzone — Wed, 29 Jul 2009 16:57:23 +0000

Thank you very much!!! it saved my day