Blocking '0000-00-00' from MySQL Date Fields

Question

I have a database where old code likes to insert \'0000-00-00\' in Date and DateTime columns instead of a real date. So I have the following two questions:

1. Is

Answer 1

Is there anything that I could do on the db level to block this?

Yes, enable the NO_ZERO_DATE mode:

SET sql_mode = 'NO_ZERO_DATE';

The behaviour is documented. Additionally, you might want to also set the mode to include NO_ZERO_IN_DATE...

Also make sure the sql_mode includes either STRICT_ALL_TABLES or STRICT_TRANS_TABLES; without these NO_ZERO_IN_DATE only give a warning, but insert still succeeds.

What is the best way to detect the existing zero values in date fields? I have about a hundred tables with 2-3 date columns each and I don't want to query them individually.

Separate columns means they have to be checked individually--nothing you can do about that.