mysql_num_rows的问题

Question

for some reason i can not understand im having troubles with mysql_num_rows.

Heres the script:

$notquery = 'SELECT * FROM notification WHERE uid = 1 AND read = 0 
AND tipo = post 
OR tipo = subpost OR tipo = logros';

$notQuery = (mysql_query($notquery));

$num_rows = mysql_num_rows($notQuery);

error:

Warning:  mysql_num_rows(): supplied argument is not a valid MySQL result resource

Answer 1

This is probably because you have an error in the query execution.
Try adding or die(mysql_error()) to debug what's going wrong...

update the code to :
$notQuery = mysql_query($notquery) or die(mysql_error());

Answer 2

You input a string into mysql_num_rows =)

You use $notquery and $notQuery mixed... That must be the silliest thing I've ever seen.

Try this:

$sql = 'SELECT .....';
$result = mysql_query($sql);
echo mysql_error()."\n";
$numRows = mysql_num_rows($result);

Obviously, this might produce the same error, since you don't check for errors :) $result might not be a MySQL resource (it might be FALSE ).

Answer 3

The sql is full with syntax error, try this

SELECT * FROM notification 
WHERE 
uid = 1 AND 
`read` = 0 AND 
tipo in('post', 'subpost', 'logros');