- Determine if JOIN resulted in any columns
- select * from AA left outer join BB on AA.keyField = BB.keyField
- where keyField = "123"
- String valueString = rs.getString("BB.keyField");
- select AA.id as aId, AA.name as aName, BB.id as bId, BB.name as bName from ...
- rs.getString("aId");
- rs.getString("bName");
- ...