| The jOOQ User Manual. Multiple Pages : SQL building : Conditional expressions : LIKE predicate | previous : next |
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LIKE predicates are popular for simple wildcard-enabled pattern matching. Supported wildcards in all SQL databases are:
- _: (single-character wildcard)
- %: (multi-character wildcard)
With jOOQ, the LIKE predicate can be created from any column expression as such:
TITLE LIKE '%abc%' TITLE NOT LIKE '%abc%'
BOOK.TITLE.like("%abc%")
BOOK.TITLE.notLike("%abc%")
Escaping operands with the LIKE predicate
Often, your pattern may contain any of the wildcard characters "_" and "%", in case of which you may want to escape them. jOOQ does not automatically escape patterns in like() and notLike() methods. Instead, you can explicitly define an escape character as such:
TITLE LIKE '%The !%-Sign Book%' ESCAPE '!' TITLE NOT LIKE '%The !%-Sign Book%' ESCAPE '!'
BOOK.TITLE.like("%The !%-Sign Book%", '!')
BOOK.TITLE.notLike("%The !%-Sign Book%", '!')
In the above predicate expressions, the exclamation mark character is passed as the escape character to escape wildcard characters "!_" and "!%", as well as to escape the escape character itself: "!!"
Please refer to your database manual for more details about escaping patterns with the LIKE predicate.
jOOQ's convenience methods using the LIKE predicate
In addition to the above, jOOQ provides a few convenience methods for common operations performed on strings using the LIKE predicate. Typical operations are "contains predicates", "starts with predicates", "ends with predicates", etc. Here is the full convenience API wrapping LIKE predicates:
-- case insensitivity
LOWER(TITLE) LIKE LOWER('%abc%')
LOWER(TITLE) NOT LIKE LOWER('%abc%')
-- contains and similar methods
TITLE LIKE '%' || 'abc' || '%'
TITLE LIKE 'abc' || '%'
TITLE LIKE '%' || 'abc'
// case insensitivity
BOOK.TITLE.likeIgnoreCase("%abc%")
BOOK.TITLE.notLikeIgnoreCase("%abc%")
// contains and similar methods
BOOK.TITLE.contains("abc")
BOOK.TITLE.startsWith("abc")
BOOK.TITLE.endsWith("abc")
Note, that jOOQ escapes % and _ characters in value in some of the above predicate implementations. For simplicity, this has been omitted in this manual.
