Having the "mysql_fetch_row()" problem. Urgently need help!

tapanan

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

This is the message code I get when executing php code to update to the mysql database. But it doesn't come all the time. Sometimes it works just fine, and sometimes this error comes up. I run both php & mysql on Linux. When running on Windows, I never get this problem.

Is there any configurations I need to do? Please help. Thank you so much.

steadyguy

It seems quite unlikely that a difference in platform will generate this error.
It is much more likely that you are getting an empty set (thus NO resource handle). This may because you're querying different databases, and they don't have the same data in them: ie., the Linux version of the (testing? development?) DB has rows that return with whatever query you're using, but the Windows version of the DB doesn't have those rows.

tapanan

There should only be one database though, since I installed and used only one.

I also found that after restarting mysql and re-doing the execution works. And it continued to work to some arbitrary point and then stop again.

steadyguy

Let's take a look at your query and your code, then ... because I still don't think it's a platform difference.

tapanan

@$db = mysql_connect("localhost", "pcidb_user", "pciuser");
mysql_select_db("smisdb");
$sql = "select * from logbook where CodeName='".$code."' and LogInTime = LogOutTime and LogInDate = '".date(Y."-".m."-".d)."'";
$result = mysql_query($sql);

if ($row = mysql_fetch_row($result)) {

<--- This is the one ... I don't know if it helps, though. I also agree that it's not about the platform, but I'm suspecting the validity of the mysql 4.0 I use. I downloaded it during the time it just came out. Not sure if it works correctly.

steadyguy

I'm sure MySQL4.0 works fine ...

Your query looks a bit odd ... Are you sure you'll have entires with LogInTime equal to LogOutTime? If those fields store what they sound like they store, then you're looking for people who logged out immediately. Also, the date section could be a bit cleaner, or could also be done more efficiently with MySQL functions like CURDATE().

$date = date(Y."-".m."-".d);
$sql = "SELECT * FROM logbook WHERE CodeName='$code' AND LogInTime= LogOutTime AND LogInDate = '$date'";

tapanan

Thanks for the date thing. I was always trying to find out some other ways to write that. 🙂

This is my first project with php. Usually I use asp & jsp. Frankly, I'm having quite a hard time trying to adjust (particularly with the . for string concat).