I would like to add a check constraint which determines if a string contains all digits, ie.
sqlite> select zip_code from zip_codes where regexp(zip_code, '^[[:digit:]]+$'); However, this generates the error: Error: no such function: regexp Searching through sqlite.org points that this function may not be included. So, is there any equivalent to this kind of functionality? I can check at the application level beforehand, but there is some solace knowing that the database can check the condition at the time of insertion too. Thanks!
