As documented under Date and Time Literals:
MySQL recognizes
DATE
values in these formats:
As a string in either
'YYYY-MM-DD'
or'YY-MM-DD'
format. A “relaxed” syntax is permitted: Any punctuation character may be used as the delimiter between date parts. For example,'2012-12-31'
,'2012/12/31'
,'2012^12^31'
, and'2012@12@31'
are equivalent.As a string with no delimiters in either
'YYYYMMDD'
or'YYMMDD'
format, provided that the string makes sense as a date. For example,'20070523'
and'070523'
are interpreted as'2007-05-23'
, but'071332'
is illegal (it has nonsensical month and day parts) and becomes'0000-00-00'
.As a number in either
YYYYMMDD
orYYMMDD
format, provided that the number makes sense as a date. For example,19830905
and830905
are interpreted as'1983-09-05'
.
Therefore, the expression 2013-05-21
is not a valid MySQL date literal (it is in fact an arithmetic expression, consisting of two subtractions: it results in the integer 1987
). In order to comply with one of the literal formats detailed above, you must either quote your date literal as a string and/or remove the delimiters.