> -----Original Message-----
> From: Artem Koutchine [mailto:[EMAIL PROTECTED]]
> Sent: Sunday, January 21, 2001 1:44 PM
> To: [EMAIL PROTECTED]
> Subject: Checking if a date is correct
>
>
> try doing
> "SELECT UNIX_TIMESTAMP('1990-2-31')"
> and you'll get a number.
> This is very weird, since this is an incorrect date.
This is the documented behavior. Section 7.4.6 of the manual:
"To make the date checking 'fast', MySQL only checks that
the month is in the range of 0-12 and the day is in the range
of 0-31" ... "This is extremely useful for applications that need
to store a birth-date for which you don't know the exact date.
In this case you simply store the date like 1999-00-00 or
1999-01-00. (You can of course not expect to get a correct value
from functions like DATE_SUB() or DATE_ADD for dates like these)."
>
> Is there any way to figure out if a date is correct in mysql
> SQL implementation?
No. You must check this yourself before entering the information
into the database. Most programming languages have this facility
built in.
> And why UNIX_TIMESTAMP does
> not return NULL for incorrect date?
See above.
/ Carsten
--
Carsten H. Pedersen
keeper and maintainer of the bitbybit.dk MySQL FAQ
http://www.bitbybit.dk/mysqlfaq
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