MySql question

[anyoldcard]

I have mostly moved and worked on my own databases and have recently moved 5 or 6 Zen cart databases. I just now noticed this at the top of one of the sql files:

SET SQL_MODE="NO_AUTO_VALUE_ON_ZERO"

I have never seen this before and it has only been on one of the 6 Zen cart databases that I have moved. Why would just this one Zen DB have it? I could probably Google "SQL MODE" and come up with something. Any help is appreciated.
Ron.

[anyoldcard]

Sorry people, I did Google and found this:

Modes define what SQL syntax MySQL should support and what kind of data validation checks it should perform. This makes it easier to use MySQL in different environments and to use MySQL together with other database servers.

I was just curious as to why only one of the Zen cart databases has this and the others did not.
Ron.