After I have seen a lot of questions here using the DATE_SUB()
or DATE_ADD()
functions instead of the arithmetic operators +
or -
The MySQL documentation for DATE_ADD (http://dev.mysql.com/doc/refman/5.1/en/date-and-time-functions.html#function_date-add) explicitly states that you may do date arithmetic with the + and - operators.
Date arithmetic also can be performed using INTERVAL together with the + or - operator:
date + INTERVAL expr unit
date - INTERVAL expr unit
Given that it's endorsed by the docs, I think any difference is stylistic. I personally think the +/- is easier to read (after all, you don't use INT_ADD(...) or DOUBLE_ADD(...) to manipulate numeric values, so why dates?). Others might have their own reasons for liking DATE_ADD and DATE_SUB, and that's fine too. Just pick something and stick with it.
Jemiah
For me, it is a matter of experience. After dealing with multiple editors, libraries, and tools that manipulate databases, I've learned not to trust the "+" and "-" operators as much as I trust DATE_SUB(). It's a lot less likely that something is going to be accidentally broken as part of the next software upgrade with DATE_SUB(), when compared to using +/-