A defined ESCAPE character in the pattern string 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 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.