xuyangzhong commented on pull request #17771: URL: https://github.com/apache/flink/pull/17771#issuecomment-969015537
The Flink's default type coercion is off now. And in order to solve the wrong result in `SELECT int = varchar`, maybe we should open the option, but it is a big work that needs full discussion. So avoid to cause the wrong result, I forbid this kind of SQL by throwing an exception. Aim to make sure "=" between other types work correctly, I write these test cases in `ImplicitConversionEqualsFunctionITCase` that you can see, because only `SELECT int = varchar` finds this bug currently. This prohibited behavior is only a **temporary** solution to this bug. To solve the bug fundamentally, we will do just what you say: > SELECT x = y produces the correct implicit cast under the scenes, and then just make sure that this implicit cast is supported in LogicalTypeCasts (in Table API). -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: issues-unsubscr...@flink.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org
