ESCAPE Feature of LIKE

Teradata Vantageā„¢ SQL Functions, Expressions, and Predicates

brand
Software
Teradata Vantage
prodname
Teradata Database
Teradata Vantage NewSQL Engine
vrm_release
16.20
category
Programming Reference
featnum
B035-1145-162K

When the defined ESCAPE character is in the pattern string, it must be immediately followed by an underscore, percent sign, or another ESCAPE character.

In a left-to-right scan of the pattern string the following rules apply when ESCAPE is specified:

  • Until an instance of the ESCAPE character occurs, characters in the pattern are interpreted at face value.
  • When an ESCAPE character immediately follows another ESCAPE character, the two character sequence is treated as though it were a single instance of the ESCAPE character, considered as a normal character.
  • When an underscore metacharacter immediately follows an ESCAPE character, the sequence is treated as a single underscore character (not a wildcard character).
  • When a percent metacharacter immediately follows an ESCAPE character, the sequence is treated as a single percent character (not a wildcard character).
  • When an ESCAPE character is not immediately followed by an underscore metacharacter, a percent metacharacter, or another instance of itself, the scan stops and an error is reported.