Flink SQL - How to parse a TIMESTAMP with custom pattern?

Question

From documentation it looks like Flink's SQL can only parse timestamps in a certain format, namely:

TIMESTAMP string: Parses a timestamp string in the form "yy-mm-dd hh:mm:ss.fff" to a SQL timestamp.

Is there any way to pass in a custom DateTimeFormatter to parse a different kind of timestamp format?

Answer 1

You can implement any parsing logic using a user-defined scalar function (UDF).

This would look in Scala as follows.

class TsParser extends ScalarFunction {
  def eval(s: String): Timestamp = {
    // your logic
  }
}

Once defined the function has to be registered at the TableEnvironment:

tableEnv.registerFunction("tsParser", new TsParser())

Now you can use the function tsParser just like any built-in function.

See the documentation for details.