INNER JOIN query help
Hi i have tried this a few ways and no results and no errors either. Im getting really tired so thought would ask for some help here.
The original query that works perfectly was
So that will grab all the queried comments left by users and list those comments on the USERID profile (USERID is a copy of SESSIONID)
and that works fine but what i want to do is not list the comments from users who have hidden their profile.
So i need to do an INNER JOIN i think. I need to grab two other values from another table called adverts adv_paused and adv_approved
Here is my latest attempt and i will try to doc for you as we go.
This does not work by the way lol
thanks in advance. :)
You can't/shouldn't mix SELECT * with the selection of individual fields.
If you are going to select individual fields (which you SHOULD do and you are doing), then kill the * part of the SELECT.
Anyway, time to DEBUG DEBUG DEBUG. Stop trying to do everything in one statement. Break it up so it's debuggable.
If you get an error from the "or die", then what is the error?
And if you copy/paste that SQL into a query tool, what does it give you?
Thanks honestly i use the sql option in phpMyAdmin all the time and i cant tell you or myself why i didnt even think of that, maybe cause i was tired i dont know but i feel pretty much like a dunce right now lol... Thanks for the reply and the lesson in proper technique... :)
Thanks i got it fixed. Appreciate the help.
I also out of curiosity did a ransack of the script and there are 65 occurances of
so im guessing that even well known scripts from well known experienced coders have made the same mistake.
i will clean it up, thank god its not causing errors right now cause that would be a nightmare lol... peace ;0
There are two problems with using SELECT *, fields
First, doing SELECT * alone is "expensive" in terms of performance. For a couple of reasons: The DB engine has to go query the schema of the table(s) to find all the fields and you may be returning much much more data than is needed. Remember, MySQL is running in one process on the computer and PHP/web server is running in another process. So *ALL* the data has to be sent from one process to another, and inter-process communication is not free.
Second, you end up with *DUPLICATE* fields in the result. That doesn't seem to cause problems for PHP, but it does for other systems. But even when it doesn't cause problems, it again causes more data than is needed to be sent across that inter-process barrier.
Now...There are a *few* cases where using SELECT *, fields can make sense. Suppose, for example, you have joined two (or more tables) and the first table has only a handful of fields and you really do need all those fields in your PHP code. So you might well do
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