Description:
According to the SQL 2003 Specification, an <interval literal> is defined as follows:
<interval literal> ::= INTERVAL [ <sign> ] <interval string> <interval qualifier>
And an <interval string> is defined thusly:
<interval string> ::= <quote> <unquoted interval string> <quote>
Currently, MySQL 5.0.16 not only doesn't require quotes, as per the spec, it doesn't even allow them.
How to repeat:
select '2005-10-10 12:00:00' - interval '1 day'
ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '' at line 1
Suggested fix:
Allow quoting. I would imagine that to strictly SQL 2003 compliant, you should error out on an unquoted interval string, but seeing as how this bug got into a production release, you might want to hold off on strict compliance til a later version.
But not allowing quotes is a very bad thing, since all other databases require them, so anything written for MySQL will break there, and vice versa.
