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sqlregexoracleoracle11gcheck-constraints

Oracle 11g - Check constraint with RegEx

I'm using Oracle 11g, and trying to create a table define constraints on the creation.

I was trying to add check constraint to validate some information (like e-mail address, phone number, etc...)

Is there something in Oracle 11g that would allow me to do something like this?

constraint CK_CONSTRAINT_NAME check (EMAIL like 'REGEX')

The regEx I wanted to use (grabbed from regexLib) is:

^[a-zA-Z][a-zA-Z0-9_\.\-]+@([a-zA-Z0-9-]{2,}\.)+([a-zA-Z]{2,4}|[a-zA-Z]{2}\.[a-zA-Z]{2})$

I think Oracle 11g (correct me if I'm wrong) doesn't support this format for RegEx...

I've seen methods using REGEX_LIKE, but it seems to only work in WHERE clauses.

I'd like to keep it as a check constraint and not a trigger or an external function/script.

Also, I've read in other threads here, someone saying RegEx' are not a good way of verifying e-mail address format and such information. No reason was given in the comment, and I'd like to know why, if a reason there is!

Solution

  • A check constraint follows the same syntax rules as conditions for a WHERE clause:

    alter table foo
  add constraint check_email 
  check (REGEXP_LIKE(email,'your_regex_goes_here','I'));

    More details in the manual:

    Edit:

    There are however some restrictions on what you can actually use in a check constraint: