[CALCITE-2360] Why doesn't Like.sqlToRegexSimilar(String sqlPattern,char escapeChar) translate "." into "\\."?

• Type: Bug
• Status: Open
• Priority: Minor
• Resolution: Unresolved
• Affects Version/s: 1.16.0
• Component/s: core
• Assignee: Unassigned
• Reporter: TANG Wen-hui
• Created: 13/Jun/18 07:50
• Updated: 22/Feb/19 01:21

Description

org.apache.calcite.runtime.SqlFunctions.similar function call Like.sqlToRegexSimilar(String sqlPattern,char escapeChar) to translate SQL SIMILAR pattern to Java regex pattern. "." in SQL SIMILAR pattern is not a metacharacter, but when Like.sqlToRegexSimilar translates it to Java regex pattern, it becomes a metacharacter.
For example, in SQL SIMILAR pattern, only string "ab." can match the pattern "ab.", but the result of org.apache.calcite.runtime.SqlFunctions.similar("ab1", "ab.") can also ruturn ture.