I’m trying to create a check constraint in MySQL to validate that a date field falls within specific boundaries. My table has a date column that stores values in ‘YYYY-MM-DD’ format.
Whenever I attempt to add this constraint, I keep getting errors. Here’s what I’m trying:
ALTER TABLE my_table
ADD CONSTRAINT
validate_date_range CHECK (event_date >= '2025-02-15' AND event_date <= '2025-11-30');
The error I receive is: ERROR 1054 (42S22): Unknown column '‘2025’ in ‘check constraint validate_date_range expression’
I’ve tried different approaches like removing quotes from the date values and using double quotes instead of single quotes, but MySQL keeps treating the date string as a column name rather than a literal date value. What’s the correct syntax for this type of date constraint in MySQL?
that’s a weird error - mysql’s probably parsing your constraint wrong. try escaping the dates differently, or u might have a character encoding issue. i’d just recreate the table with the constraint from scratch instead of using alter table. sometimes that works better than adding constraints after the fact.
The syntax looks right for MySQL 8.0.16+, but that error means MySQL isn’t parsing your date string correctly. Try wrapping your strings with the DATE function: ALTER TABLE my_table ADD CONSTRAINT validate_date_range CHECK (event_date >= DATE('2025-02-15') AND event_date <= DATE('2025-11-30')); This forces MySQL to treat them as actual dates instead of trying to read them as column names. I’ve hit this same issue before - the constraint parser gets confused with string delimiters, and DATE() usually fixes it.
yea, it could be your mysql version. check if it’s 8.0.16 or newer, otherwise constraints won’t function right. you can run SELECT VERSION(); to see what’s installed.
I encountered a similar issue recently. MySQL’s check constraint parser can be tricky with date literals. You might want to try using the STR_TO_DATE function instead: ALTER TABLE my_table ADD CONSTRAINT validate_date_range CHECK (event_date >= STR_TO_DATE('2025-02-15', '%Y-%m-%d') AND event_date <= STR_TO_DATE('2025-11-30', '%Y-%m-%d')); This ensures the string is converted into a date format that MySQL recognizes. Additionally, confirm that your event_date column is indeed of type DATE and not VARCHAR, as that could complicate parsing as well. It should work properly once MySQL can interpret the date boundaries correctly.
Had this exact problem last month - turned out to be a quoting issue with my MySQL client. The error means MySQL can’t parse your date string, usually because the client’s passing quotes weird. Try running it directly in MySQL Workbench or command line instead of whatever tool you’re using. Also check for hidden characters in your SQL - copy-pasting from forums sometimes introduces Unicode quotes that look normal but break parsing. If that doesn’t work, define the constraint during table creation instead of altering after. Way more reliable in my experience.