[FLINK-21435] Add a SqlExpression in table-common

• Type: Sub-task
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 1.13.0
• Component/s: Table SQL / API
• Labels: pull-request-available
• Assignee: Timo Walther
• Reporter: Timo Walther
• Created: 22/Feb/21 10:06
• Updated: 26/Feb/21 11:56
• Resolved: 23/Feb/21 08:17

Description

We introduced a dedicated function definition in FLINK-20971 to use SQL expression in Table API. However, for usability and clear Maven module design it is better add a dedicated `SqlExpression` in `table-common`. This allows catalogs to specify an unresolved SQL expression without a dependency on `table-api` furthermore we can add SQL specific functions to the new `Schema` class.

Issue Links

• links to: GitHub Pull Request #14986
• links to: GitHub Pull Request #14996