Would like to update a table based on 1 row being returned from a join.

Question

Hi, hope you guys can help.
I'd like to update 1 rown that is returned from a join query. The following code returns 1 row.
SELECT pt.*, pv.* FROM
--SELECT pt.template_id, pt.property_code, pv.value FROM
property_template pt inner join
property_value pv on pt.template_id = pv.template_id
WHERE property_code = '500_URL';
Based on the row returned i'd like to update a column called VALUE from the property_value table.
I've tried the following code but it updates every row in the value column.
update property_value set value = 'http://10.14.64.170:8080/XTI/UPLOAD'
where exists
SELECT pt.*, pv.* FROM
--SELECT pt.template_id, pt.property_code, pv.value FROM
property_template pt inner join
property_value pv on pt.template_id = pv.template_id
WHERE property_code = '500_URL'
Any help with this would be appreciated.

Answer 1

You need this
UPDATE property_value   pv
   SET value            = 'http://10.14.64.170:8080/XTI/UPLOAD'
WHERE EXISTS            (
                         SELECT 1
                           FROM property_template   pt
                          WHERE pt.template_id      = pv.template_id
                            AND property_code       = '500_URL'
                        );Regards
Arun