Question

Disclaimer: this is needed for an old and ugly codebase that I’d much rather not touch.

• There is a table in the database that has a column (among many others) of DATE type.
• There is a query (auto generated by Torque criteria – don’t ask) with java.util.Date parameter; Torque formats it as full datetime.

So, the query MySQL is getting is something like:

SELECT * FROM my_table
 WHERE my_date = '20091201105320'; // 2009-12-01 10:53:20

The problem is that on one server which has MySQL 5.0.27-standard it works just fine – as in returns all the records from my_table that have my_date set to ‘2009-12-01’. On another server which has MySQL 5.0.45 it does not work. The data is there – if I manually run the query after trimming the time portion out I get correct results back.

The question is:

Is there a setting somewhere, either in MySQL configuration file or in per-session variables (connection string) or somewhere else to force MySQL to ignore the time portion during string constant to date conversion?

I obviously can’t use DATE() function without changing the codebase which I’d much rather not.

Answer 1

Apparently I’m out of luck. From MySQL manual:

Prior to MySQL 5.0.42, when DATE values are compared with DATETIME values, the time portion of the DATETIME value is ignored, or the comparison could be performed as a string compare. Starting from MySQL
5.0.42, a DATE value is coerced to the DATETIME type by adding the time portion as '00:00:00'.

Should anyone find themselves in a similar situation, the only workaround I found was to:

1. Reset time fields (hours / minutes / seconds) of the java.util.Date instance to zero.
2. Patch (and I do mean “patch” – there is no way to plug in your own adapter) getDateString() method of Torque’s DB adapter for MySQL (org.apache.torque.adapter.DBMM) to check whether time fields of a date are zeroes and, if so, use “date-only” format.