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How to delete multiple rows from multiple joined tables
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* How to delete multiple rows from multiple joined tables
@ 2003-05-26 13:48 Michael Mattox <michael.mattox@verideon.com>
  2003-05-26 16:55 ` Re: How to delete multiple rows from multiple joined tables Tom Lane <tgl@sss.pgh.pa.us>
  0 siblings, 1 reply; 2+ messages in thread

From: Michael Mattox @ 2003-05-26 13:48 UTC (permalink / raw)
  To: pgsql-sql

I'm trying to use SQL to delete multiple rows from multiple tables that are
joined together.  From what I've seen delete can only delete from a single
table, which is OK because I can just do separate deletes for each table.
But the problem is how do I specify which rows to delete?  For example:

Table A is joined to Table B
Table B is joined to Table C

I want to delete all rows in table C & B that correspond to a row in Table
A.  Here's my exact SQL which actually deletes all the rows:

delete from monitorstatusitemx where monitorx.namex='STRESS_TEST' and
monitorstatusx.jdoidx = monitorstatus_statusitemsx.jdoidx and
monitorstatus_statusitemsx.statusitemsx =
monitorstatusitemlistd8ea58a5x.jdoidx and
monitorstatusitemlistd8ea58a5x.statusitemlistx = monitorstatusitemx.jdoidx

(It's a little ugly because I'm using JDO which generates the schema.
Unfortunately deletes with JDO are very slow so I need to use SQL for this.)

Michael





^ permalink  raw  reply  [nested|flat] 2+ messages in thread

* Re: How to delete multiple rows from multiple joined tables
  2003-05-26 13:48 How to delete multiple rows from multiple joined tables Michael Mattox <michael.mattox@verideon.com>
@ 2003-05-26 16:55 ` Tom Lane <tgl@sss.pgh.pa.us>
  0 siblings, 0 replies; 2+ messages in thread

From: Tom Lane @ 2003-05-26 16:55 UTC (permalink / raw)
  To: michael.mattox@verideon.com; +Cc: pgsql-sql

"Michael Mattox" <michael.mattox@verideon.com> writes:
> I want to delete all rows in table C & B that correspond to a row in Table
> A.

Depending on how automatic you want that to be, perhaps foreign keys
would do what you want?  You could set up B's and C's links to A as
"on delete cascade" foreign keys, and then a deletion from A would
clean them up too.

			regards, tom lane



^ permalink  raw  reply  [nested|flat] 2+ messages in thread


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2003-05-26 13:48 How to delete multiple rows from multiple joined tables Michael Mattox <michael.mattox@verideon.com>
2003-05-26 16:55 ` Tom Lane <tgl@sss.pgh.pa.us>

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