Ambiguous behavior of Joins with ON clause

[prabhatkashyap]

Hello,

When ever I'm trying to run following query

select * from emp4 left join emp5 on emp4.id=emp4.name;

  it executes successfully.

But when I m trying to run :

select * from emp4 left join emp5 on emp4.id=emp5.name;

It gave error

Error: java.lang.ClassCastException: java.lang.Integer cannot be cast to java.lang.String

Similarly

select * from emp5 join emp4 on emp4.id=emp5.name;

Is working but

select * from emp5 left join emp4 on emp5.id=emp4.name;

Not working

Please confirm.