Newbie UPDATE request.

Question

Hello everyone.
I'm trying to move a whole bunch of data from Table1 to Table2, using the UPDATE function, but only under special circumstances.
I wish to move all available addressId's from Table1 to Table2, but only if there isn't an addressId in Table2 already.
Example data.
Table1
Table1_ID(PK) -- ADDRESSID(FK)
1----------------100
2----------------200
3----------------(null)
4----------------300
5----------------400
Table2
Table2_ID(PK) -- Table1_ID(FK) -- ADDRESSID(FK)
10----------------1----------------100
20----------------2----------------600
30----------------2----------------(null)
40----------------2----------------(null)
50----------------3----------------(null)
60----------------4----------------(null)
70----------------5----------------700
(Note that the addressId in Table2 and it's referenced row in Table1 doesn't necesarily have to be the same. They can have independant adresses. All I wish is to fill the blank spots in Table2 if there's an available adressid in the row it's refering to in Table1)
Desired result:
Table2
Table2_ID(PK) -- Table1_ID(FK) -- ADDRESSID(FK)
10----------------1----------------100
20----------------2----------------600
30----------------2----------------200
40----------------2----------------200
50----------------3----------------(null)
60----------------4----------------300
70----------------5----------------700
I've tried to display the relationship between the tables above, but to clarify;
Table2 has a FK to Table1. Multiple records in Table2 may point at the same record in Table1. Table1 doesn't know anything about Table2. Both tables have a FK to an address table.
I hope it makes sense, otherwise I'm sorry to have wasted your time :)
I've tried something sorta like this.
UPDATE TABLE2 T2
SET T2.ADDRESSID = T1.ADDRESSID
WHERE T2.ADDRESSID IS NULL AND EXISTS
(SELECT T1.ADDRESSID
FROM Table1 T1
WHERE T1.ADDRESSID IS NOT NULL
AND T1.TABLE1_ID = T2.TABLE1_ID)
Compiler throws this:
Invalid identifier T1.ADDRESSID. (Bold'd above)
I'm sure it's out of scope, since the T1 alias is defined inside the select block.
Anyways... I've chipped away at this for a couple of hours now, but with no luck. It would'nt surprise me at all if what I'm looking for is a 1 liner or something :)
Have a nice day :)
/LW
EDIT: Markups didn't seem to work for me.
Edited by: 873998 on 2011-07-21 01:55

Answer 1

Welcome to the forum
EDIT: Markups didn't seem to work for me.See the SQL and PL/SQL FAQ: SQL and PL/SQL FAQ ( #9) Formatting with {noformat}{noformat} Tags )