Say a table has several subclass types. How can I see all columns from different types in sqldeveloper? In table view, only can see common columns. Thanks.
This is not possible in SQL Developer as it currently stands (as of 1.5.4).
Incidentally it isn't possible in SQL*PLus either. Setting DESCRIBE DEPTH 2
just shows more detail regarding the super type:
SQL> desc my_people
Name Null? Type
----------------------------------------- -------- --------------------
CREATE_DATE NOT NULL DATE
ID NOT NULL NUMBER
DETAILS PERSON
SQL> set describe depth 2
SQL> desc my_people
Name Null? Type
----------------------------------------- -------- --------------------
CREATE_DATE NOT NULL DATE
ID NOT NULL NUMBER
DETAILS PERSON
PERSON is NOT FINAL
NAME VARCHAR2(30 CHAR)
SQL>
(I checked. set describe depth 3
doesn't do anything, what it controls is the expansion of types used as attributes of the displayed types.)
I don't know the reason for sure but I would hazard a guess that it is something to do with the unbounded number of levels of sub-types permitted. Furthermore, Types are relatively new and still under appreciated in the database. Oracle is primarily relational and procedural, and the object-oriented features are treated as red-headed step-children.
Of course, SQL Developer is extensible, so it would be possible to write an addon which does this expansion. Hmmm....