I’m working on a MySQL database project and need to verify whether certain values are actually integers before processing them further. I know MySQL has functions like CAST() and CONVERT() that can transform data into integer format, but I can’t seem to find a built-in function that simply tests if a value is already an integer.
For example, in PHP I would use is_int() to check this. Is there something similar in MySQL? I need to filter out non-integer values from my queries and only work with legitimate whole numbers. What would be the most reliable approach to accomplish this validation in MySQL?
u can use CAST(value AS UNSIGNED) and see if it equals the original value. if it does, then it’s an int. just remember to manage nulls first to avoid errors.
I use regular expressions with the REGEXP operator - it’s the most reliable method I’ve found. For positive integers only: WHERE column_name REGEXP '^[0-9]+$'. If you need negatives too: WHERE column_name REGEXP '^-?[0-9]+$'. This works great because it validates the actual string instead of trying to convert it first. I’ve used this tons in data cleanup projects to catch malformed numeric data before importing into stricter schemas. The regex approach is perfect for VARCHAR columns that should be integers but have extra characters or formatting problems.
I’ve encountered similar issues while cleaning up legacy databases. An effective method is to use CAST() together with a comparison check for error handling. Specifically, check if CAST(your_column AS SIGNED) = your_column to ensure accuracy. It’s important to note that MySQL will remove any leading zeros during the cast, so ‘007’ will be transformed to 7. To preserve the original format, you should implement a LENGTH() check to confirm that the cast result has the same character length as the original value. This can help identify unusual edge cases that regular expressions might overlook, particularly with numbers that could exceed MySQL’s integer limits.
honestly, the easiest approach i’ve found is value REGEXP '^-?[0-9]+$' AND value BETWEEN -2147483648 AND 2147483647 - catches both format and range problems. saves a lot of headaches with edge cases.