Currently, it is not easily possible to reference columns in the main select from a subselect.
For example, to select authors which have published exactly one book, one can use the SQL:
SELECT * FROM author WHERE (SELECT COUNT FROM book WHERE book.author_id=author.author_id)=1
One would like to achieve this by
Criteria subselect = new Criteria();
Criteria criteria = new Criteria();
List<Author> result = AuthorPeer.doSelect(criteria);
but the SQL results in (note the additional author in the from clause of the subselect)
SELECT * FROM author WHERE (SELECT COUNT FROM book, author WHERE book.author_id=author.author_id)=1
So the desired behavior is:
If a table also exists in the from clause of the outer criteria, it should not be added to the from clause of the subselect
NOTE1: This change can change the behaviour of Torque in existing code
NOTE2: Workarounds exist, e.g. defining the FROM clause of the subselect manually using Criteria.addFrom() or using "new ColumnImpl(null,null,null,AuthorPeer.AUTHOR_ID.getSqlExpression())" as join column in the WHERE clause of the subselect.
|Make PreparedStatementPart an interface||Resolved|