Support UNION generation for kotlin

[white-ws]

Thank you for a great library.

I tried to create a union query using Kotlin extension methods, but seems like union() method from QueryExpressionWhereBuilder isn't supported at the moment. Is there any workaround to do this ?

[jeffgbutler]

I'm glad you are liking MyBatis Dynamic SQL!

You are correct that union support is missing right now. I've been thinking about how to implement this - what the syntax should be. I don't have a strong feeling about that yet. I will probably post some alternatives and ask for feedback.

In the meantime, if you have a suggestion as to what the syntax should be I would love to see it.