Re: time field query problems.

Steve, > For some reason the below statement is not working. Can anyone tell me why? > > Select EDIT_LOCK from ordmaster where EDIT_LOCK + INTERVAL 10 MINUTE < now() > AND ORDER_NO = '5' AND EDIT_LOCK > 0; > > -EDIT_LOCK is a MySQL (ver 3.23.49-max) time field, allows nulls, default is > NULL. > > If this cannot be done in a query, whats the best way to compare time in > php? The best way to compare time in PHP is to use the MySQL RDBMS that is managing/retrieving the data for you. Recommendation 1: do not use a Time field (you did mean the back 'half' of a Date-time field didn't you?). Because you are (apparently only) using this field to temporarily lock a row, the value is only ever used for computation (cf display). A Timestamp field is best for computation - a Time field for presentation. Consider also storing such data as an integer field or beware the automatic update feature for Timestamp fields. Recommendation 2: re-consider the (default) use of NULL - this may be the root of the question you're asking: what if the row has never been 'locked' and attempt the (above) SELECT? (then the last comparison clause would be illogical) If the default were zero (0 or 00:00:00) and the retrieval logic updated slightly, things should be less complicated. Regards, =dn