------- Comment #6 From bht 2010-11-25 02:21:31 (-) [reply] -------

There are multiple nested duplicates.

If the chain of duplicates is correct, then the description may have to be
changed to something like:

"In Database Explorer, two tables cannot be dropped at all if both have foreign
key contraints referencing each other"

This is a very irritating showstopper because Database explorer does not
provide a means to copy the names of foreign key constraints to the clipboard.

It might not be a big issue to drop constraints before dropping tables, and
therefore, I change the priority to hopefully get this done in the next
release.

------- Comment #7 From bht 2010-11-25 02:29:03 (-) [reply] -------

Testcase:

This is relevant for one-to-one relationships.

Testcase:

CREATE TABLE TABLE_1 (ID INTEGER NOT NULL, TABLE_2_ID INTEGER NOT NULL, PRIMARY
KEY (ID));
CREATE TABLE TABLE_2 (ID INTEGER NOT NULL, TABLE_1_ID INTEGER NOT NULL, PRIMARY
KEY (ID));
ALTER TABLE TABLE_1 ADD CONSTRAINT FK_TABLE_1_TABLE_2_ID FOREIGN KEY
(TABLE_2_ID) REFERENCES TABLE_2 (ID);
ALTER TABLE TABLE_2 ADD CONSTRAINT FK_TABLE_2_TABLE_1_ID FOREIGN KEY
(TABLE_1_ID) REFERENCES TABLE_1 (ID);

When trying to drop the tables in Database Explorer by right click|delete, the
error is:
Unable to execute command:
drop table "APP"."TABLE_2"
Operation 'DROP CONSTRAINT' cannot be performed on object 'SQL100704071938090'
because CONSTRAINT
'FK_TABLE_1_TABLE_2_ID' is dependent on that object.

This looks like a bug because Database Explorer seems to try to drop
constraints two times.

This worked as expected:

ALTER TABLE TABLE_1 DROP CONSTRAINT FK_TABLE_1_TABLE_2_ID;
ALTER TABLE TABLE_2 DROP CONSTRAINT FK_TABLE_2_TABLE_1_ID;
DROP TABLE TABLE_1;
DROP TABLE TABLE_2;