Outer joins of views and derived tables

Outer joins can also be specified for views and derived tables.

The statement

SELECT *
FROM V LEFT OUTER JOIN A ON (V.x = A.x);

can be interpreted as follows:

  • Compute the view V.

  • Join all the rows from the computed view V with A by preserving all the rows from V, using the join condition V.x = A.x.

 Example