[FLINK-11221] Support delimited identifiers in TableAPI

• Type: Improvement
• Status: Open
• Priority: Not a Priority
• Resolution: Unresolved
• Component/s: Table SQL / API
• Labels: auto-deprioritized-major auto-deprioritized-minor auto-unassigned
• Assignee: Unassigned
• Reporter: Hequn Cheng
• Created: 26/Dec/18 13:51
• Updated: 25/Dec/21 22:38

Description

There are two kinds of identifiers in SQL: regular identifiers and delimited identifiers. Different from regular identifiers, delimited identifiers are identifiers enclosed in double backticks(``), double quotation marks (") or brackets ([ ]). 

Currently, delimited identifiers in double backticks have been supported in Flink SQL(thanks to Calcite). In Calcite, delimited identifiers may contain virtually any character, including spaces and other punctuation. With delimited identifiers, we can name some special identifiers such as `a-a` which may be an essential requirement.

However, delimited identifiers are not supported in TableApi. It would be nice if we support it in TableApi. 

Any suggestions are welcomed! Thank you.