Update then select

[isedeasy]

I need to increment a value in a row of my table, I also want to get that value.

 

mysql_query("UPDATE deals SET likes = likes + 1 WHERE id = '$deal'");

 

How would I get the value of 'likes' without doing a separate select query?

 

Cheers for any help.

[fenway]

Read the refman on LAST_INSERT_ID() with with a parameter -- very cool, mostly unknown functionality, explicitly for this purpose.

[isedeasy]

Hi

 

Cheers for the pointer, I had a look at the manual but I can't quite get my head around it, do I still need to-do select query.

 

Sorry I am very new to php and mysql and I want to make sure I use functions correctly.

[fenway]

Yes, you'll need to run "SELECT LAST_INSERT_ID()" afterwards, but not a true mysql query.

[isedeasy]

Im still having problems 

 

I feel so stupid

 

I tried the following but it does not work

 

$likes = mysql_query("SELECT LAST_INSERT_ID(likes)");

[fenway]

Show me the update statement.

[isedeasy]

mysql_query("UPDATE deals SET likes = likes + 1 WHERE id = '$deal'");

[fenway]

Well, you're not using LAST_INSERT_ID() in your UPDATE statement, so of course it doesn't work.

[isedeasy]

I would not normally ask but this is starting to-do my head in lol

 

Could you write an example of how to use the function?

 

Thanks

 

 

[Philip]

If I understand it correctly, you're wanting to basically combine your UPDATE/SELECT queries...

Currently' date=' you cannot update a table and select from the same table in a subquery.[/quote']

[fenway]

Try this:

mysql_query("UPDATE deals SET likes = LAST_INSERT_ID(likes + 1) WHERE id = '$deal'");

 

Followed by:

$likes = mysql_query("SELECT LAST_INSERT_ID()");

 

Hope that helps.

 

[isedeasy]

When I try that $like returns

 

Resource id #8

 

Cheers for your help, I appreciate it 

[premiso]

$res = mysql_query("SELECT LAST_INSERT_ID()");
$likes = mysql_fetch_row($res);
$likes = $likes[0];
echo $likes;

 

You have to fetch the data to display it as seen above.

[isedeasy]

Getting there

 

That returns the value of 'likes' twice

 

eg if likes = 10, I get

 

1010

[fenway]

That's hard to believe... the sql works.