MySQL Cookbook

Using Patterns to Match Broad Content Types

Problem

You want to classify values into broad categories.

Solution

Use a pattern that is similarly broad.

Discussion

If you need to know only whether values are empty, nonempty, or consist only of certain types of characters, patterns such as the following may suffice:

Pattern	Type of value the pattern matches
/^$/	Empty value
/./	Nonempty value
/^\s*$/	Whitespace, possibly empty
/^\s+$/	Nonempty whitespace
/\S/	Nonempty, and not just whitespace
/^\d+$/	Digits only, nonempty
/^[a-z]+$/i	Alphabetic characters only (case insensitive), nonempty
/^\w+$/	Alphanumeric or underscore characters only, nonempty