Database Reference
In-Depth Information
Figure 10.19
Left Outer Join
Between ARTIST,
GUESTAPPEAR
ANCE, and
SONG Tables.
Notice in the Oracle-formatted query in Figure 10.19 that the two left
outer joins are identified by the (+) symbol next to the appropriate columns
in the WHERE clause.
Here is another variation that returns the same result. In the following
query, the Oracle format uses an embedded subquery statement (see Chap-
ter 12) rather than a WHERE clause addition using the SONG and GUE-
STAPPEARANCE tables. SQL is very versatile. There are many options
available in SQL.
