Re: May I have an assistance on CREATE TABLE Command - Mailing list pgsql-sql

From James Kitambara
Subject Re: May I have an assistance on CREATE TABLE Command
Date
Msg-id 564943.99946.qm@web27907.mail.ukl.yahoo.com
Whole thread Raw
In response to Re: May I have an assistance on CREATE TABLE Command  ("Bart Degryse" <Bart.Degryse@indicator.be>)
Responses Re: May I have an assistance on CREATE TABLE Command
Re: May I have an assistance on CREATE TABLE Command
Re: May I have an assistance on CREATE TABLE Command
List pgsql-sql
 
Thank you !
 
But I think that there is a solution.
 
If it happens that you have the following data in your tables
REGION
--------------------------------------
region_id  | region_name
--------------------------------------
   11        | Dodoma
   22        | Tabora
   99        | Dar es Salaam      THIS ROW WAS SUPPOSED TO BE: '33', 'Dar es Salaam'
 
DISTRICT
------------------------------------------------------------
dist_id     |  dist_name          |    region_id
------------------------------------------------------------
  001       |  Kongwa              |    11
  002       |  Ilala                    |    99
  003       |  Temeke              |    99
  003       |  Kinondoni           |    99
 
 
For this UPDATE I wanted, when I change the region _id from '99' to '33' of the last ROW in REGION table  AUTOMATICALLY to change the last three ROWS of the DISTRICT table which reference to  '99', 'Dar es Salaam'.
 
If I do this, I will get the error message "You can not change region_id other tables are reference to it.
 
HOW CAN DO THIS? (AUTOMATIC UPDATE OF FOREIGN KEY)
   
 
-----------------------------------ORGINAL MESSAGE---------------------------------------

I think (one of) the point(s) of id fields is not to change them. You can update the region_name field (eg a correct a misspelling), but the id stays the same.
That way the district stays connected to the same region.

>>> James Kitambara <jameskitambara@yahoo.co.uk> 2008-09-17 8:50 >>>
 
Hello Mambers of PGSQL-SQL,
 
I have two tables namely:
 
    REGION (region_id, region_name)
    DISTRICT (dist_id, dist_name, region_id (FK))
 
I would like to have the CREATE TABLE Command which will create these tables in such a way that when REGION table is UPDATED automatical the FOREGN KEY in DISTRICT  table is also updated.
 
I will appriciate for your assistance !

Regards
 
James Kitambara

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