- Join – regular query
- Union – union query
In the case of union query several datasources of the same type (the same table) can be placed on the query datasource root node. Note, that all datasources except the first one will have a property called UnionType, which specifies what should be done with duplicated records that may appear because of union:
- Union – remove duplicated records
- UnionAll – keep duplicated records
Additional datasources can be added to the deeper levels of the query under any datasource that participates in union. Those will be translated into joins. The only allowed join types for the union query are exists and notexists join.