sql qurey

[kayoto]

hello all
i need your's help here i got this error message:Warning: mysql_fetch_array() expects parameter 1 to be resource, boolean given when i run this query :"SELECT Man_hours_per_month
FROM productivity
WHERE key = SELECT MAX(key)
FROM productivity"

and i dont understand what is the problem here
thank you for help

kayoto

[johanafm]

You are trying to call mysql_fetch_array with boolean false as an argument, rather than a result set resource. I.e.

$var = false;
mysql_fetch_array($var);

If you checked the result of your query (boolean false on error, result set resource otherwise) and proceeded to display the sql error number/message (mysql_errno(), mysql_error()) when it is false, mysql_fetch_array when it's not, then you'd see something along the lines of: You have an error in your SQL syntax .... near 'key'
Since key is a reserved word.

[Ashley_Sheridan]

Also, I think your query might run faster if you changed it to:

SELECT Man_hours_per_month
FROM productivity
ORDER BY key DESC
LIMIT 1

As this will cut out one of your select statements. This will become more noticeable on tables with large datasets.