check for NULL in query

[gammaman]

Can I test for NULL in a query, something like this, but this does not work.

 

$result=mysql_query("select CourseID,StudentID, Grade FROM Rcourse
             WHERE CourseID ='$CourseID'  AND StudentID = '{$_SESSION['student']['user']}'
          AND Grade = NULL");

[dptr1988]

Use 'Grade IS NULL' rather then 'Grade = null'

 

[dptr1988]

Some more info from the mysql manual:

 

http://dev.mysql.com/doc/refman/5.0/en/working-with-null.html

[gammaman]

No, that did not work.  Maybe I am not explaining myself correctly.  I want the query to select the row where the Grade field has no value yet.

[dptr1988]

What is the default value for the grade column? If the column definition contains a default value, then use that value.

 

 

[DarkWater]

$result=mysql_query("select CourseID,StudentID, Grade FROM Rcourse

            WHERE CourseID ='$CourseID'  AND StudentID = '{$_SESSION['student']['user']}'

          AND Grade IS NULL");

 

That SHOULD work. O_O Works for me.

[gammaman]

The default value is NULL, meaning there is no defalut value.  Still cannot get it working.

[DarkWater]

Do you get any mysql errors, or just no rows returned?

[gammaman]

Funny, but your code seems to be working now, I think I may have forgotten to reload the page after uploading the new version onto the server.  I will let you know if I run into any more problems.

 

P.S. : I don't have the code available right now but you were helping me with an insert query using $_SESSIONS early today and I still cannot get that working either.  Thanks for all of your help.

[DarkWater]

If you want me to really look at the INSERT issue, censor out your database details and send me the connect, config, and insert scripts and I'll have a look.  Put them all in a zip or tar file and put them on like, megaupload.