[ASTERIXDB-2651] Handle matching a literal backslash properly in LIKE

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 0.9.4
• Fix Version/s: 0.9.5
• Component/s: FUN - Functions
• Assignee: Ali Alsuliman
• Reporter: Ali Alsuliman
• Created: 03/Oct/19 18:36
• Updated: 05/Nov/19 21:57
• Resolved: 05/Nov/19 21:57

Description

Fix matching a literal backslash in LIKE. As an example,
 

SELECT "test\\string" LIKE "%\\\\%"

Also, fix the issue with a dynamic and changing pattern in regexp_*() functions (and functions using regex matcher class). Here is an example, for a dataset with the below tuples

{ "id": 1, "test_str": "hello world", "pattern": "h"}
{ "id": 2, "test_str": "hello world", "pattern": "H"}

FROM ds SELECT regexp_contains(test_str, pattern, "i"); -- "i" flag means case insenstive