LIKE predicate

The LIKE predicate searches a string value for a certain pattern.

The syntax for this predicate is:
string-expression   [NOT]  LIKE  pattern    [ ESCAPE escape-character ]

The pattern value is a string literal or parameter marker of type string in which the underscore ( _ ) stands for any single character and percent ( % ) stands for any sequence of characters ( including empty sequence ). Any other character stands for itself. The escape character can be used to search for character _ and %. The escape character can be specified as a string literal or an input parameter.

If the string-expression is null, then the result is unknown.

If both string-expression and pattern are empty, then the result is true.

Example: LIKE predicate

  • LIKE is true
  • LIKE % is true
  • e.name LIKE 12%3 is true for 123 12993 and false for 1234
  • e.name LIKE 's_me' is true for some and same, false for soome
  • e.name LIKE '/_foo' escape '/' is true for _foo, false for afoo
  • e.name LIKE '//_foo' escape '/' is true for /afoo and for /bfoo
  • e.name LIKE '///_foo' escape '/' is true for /_foo but false for /afoo