The like Sql condition in Oracle Database SQL
where the pattern can contain special pattern-matching characters:
- An underscore (_) in the pattern matches exactly one character (as opposed to one byte in a multibyte character set) in the value.
- A percent sign (%) in the pattern can match zero or more characters (as opposed to bytes in a multibyte character set) in the value. The pattern '%' cannot match a null.
You can include the actual characters % or _ in the pattern by using the ESCAPE clause, which identifies the escape character.
SELECT 'true' FROM dual WHERE '1' LIKE '_' ESCAPE '\';
will return true because 1 is a character.
SELECT 'true' FROM dual WHERE '1' LIKE '\_' ESCAPE '\';
will return nothing because 1 is different from an underscore.