[FLINK-20971] Allow SQL expressions in Table API

• 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: 14/Jan/21 09:30
• Updated: 28/May/21 07:11
• Resolved: 19/Jan/21 13:11

Description

Both FLIP-136 and FLIP-129 assume that a table schema is able to store both a SQL expression and a Table API one. Therefore we should introduce an expression in Table API that allows to use SQL expressions. This is also useful for other use cases where people prefer SQL expressions in Table API.

An expression `callSql(String)` next to `call(udf)` can offer scalar operations such as:

table.select(callSql("1+1"), 12, call(Udf.class, $("f0")))

Issue Links

• blocks: FLINK-17793 Replace TableSchema with dedicated CatalogSchema
• links to: GitHub Pull Request #14660