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How i can change all foreign keys in ASA 9 database to cascade?



asked 19 Oct '12, 08:13

DRauber's gravatar image

accept rate: 0%

edited 19 Oct '12, 08:13

AFAIK you will have to drop each foreign key and recreated it with the new constraints.

ALTER TABLE "sirius"."TestTable" DROP FOREIGN KEY "FKTestTable";

You might be able to write a generic script the uses informations about the defines foreign keys, generate the ALTER statements and execute them (EXECUTE IMMEDIATE). While surely it's not a trivial task, that should be possible (YMMV).

Alternatively you could unload the structure to a reload.sql file and modify it accordingly for that task.

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answered 19 Oct '12, 08:47

Reimer%20Pods's gravatar image

Reimer Pods
accept rate: 11%

FWIW, writing a generic script is certainly doable, however, I've often found the SQL Anywhere system tables/views quite difficult to use for such cases. (I.e. IMHO it's not that easy to find out which columns of which tables to look for to get the required information, as long as constraints are included. - It's rather easy for table/column names or procedures and the like.)

And it has not become easier with the big system catalo change in v10...

That might be a situation where a few more samples could be helpful:)

(19 Oct '12, 09:26) Volker Barth

mmmm its hard work!

in another database server (postgresql) i can execute: delete cascade TestTable where condition;

Has ASA 9 any option to do this?


(19 Oct '12, 09:38) DRauber
Replies hidden

AFAIK, the options to declare FK relationships and RI actions like RESTRICT or CASCADE are rather similar for PostgreSQL and SQL Anywhere (and conform to the SQL standards).

Do you say you can call "delete cascade TestTable ..." in PostgreSQL, and that will delete rows from the TestTable and from all according child tables that are declared with ON DELETE RESTRICT (which would otherwise prevented because of the RESTRICT action)? - I'm not aware of such a statement in PostgreSQL.

(19 Oct '12, 10:18) Volker Barth

Just in case you just would need this once (to "clean-up" dependent data), you could of course DELETE the child table rows beforehand - that might be easier, such as

delete from FkTestTable where RT_ID in
   (select RT_ID from RefTable where condition = ...);
delete from RefTable where condition = ...)
(19 Oct '12, 10:21) Volker Barth

Sorry, I confused things, you can not really do too well in postgres

(19 Oct '12, 10:41) DRauber

yes, I always do so, but I have many cascade foreign keys... Tanks a lot!

(19 Oct '12, 10:43) DRauber
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question asked: 19 Oct '12, 08:13

question was seen: 6,317 times

last updated: 19 Oct '12, 10:43