escape

The percent sign % and underscore _ are metacharacters within SQL LIKE clauses. JDBC provides syntax to force these characters to be interpreted literally. The JDBC clause immediately following a LIKE expression allows you to specify an escape character:

Syntax

WHERE CharacterExpression [ NOT ] LIKE
    CharacterExpressionWithWildCard
    { ESCAPE 'escapeCharacter' }

Example

-- find all rows in which a begins with the character "%" 
SELECT a FROM tabA WHERE a LIKE '$%%' {escape '$'}
 -- find all rows in which a ends with the character "_" 
SELECT a FROM tabA WHERE a LIKE '%=_' {escape '='}

Note:

? is not permitted as an escape character if the LIKE pattern is also a dynamic parameter (?).

In some languages, a single character consists of more than one collation unit (a 16-bit character). The escapeCharacter used in the escape clause must be a single collation unit in order to work properly.

You can also use the escape character sequence for LIKE without using JDBC's curly braces; see LIKE.