[FLINK-36100] Support ESCAPE in built-in function LIKE formally

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 1.20.0, 1.19.1
• Fix Version/s: 2.0-preview
• Component/s: Table SQL / Planner
• Labels: pull-request-available
• Assignee: Dylan He
• Reporter: Dylan He
• Created: 20/Aug/24 02:09
• Updated: 02/Sep/24 09:35
• Resolved: 26/Aug/24 14:59

Description

Flink does not formally support ESCAPE in built-in function LIKE, but in some cases we do need it because '_' and '%' are interpreted as special wildcard characters, preventing their use in their literal sense.

And currently, if we forcefully use ESCAPE characters, we will get unexpected results like the cases below.

> SELECT 'TE_ST' LIKE '%E\_S%';
 FALSE
> SELECT 'TE_ST' LIKE '%E\_S%' ESCAPE '\';
 ERROR

Issue Links

• links to: GitHub Pull Request #25225