updating table rows in postgres using subquery

Question

Using postgres 8.4, My goal is to update existing table:

CREATE TABLE public.dummy
(
  address_id SERIAL,
  addr1 character(40),
  addr2 character(40),
  ci         


        

Answer 1

You're after the UPDATE FROM syntax.

UPDATE 
  table T1  
SET 
  column1 = T2.column1 
FROM 
  table T2 
  INNER JOIN table T3 USING (column2) 
WHERE 
  T1.column2 = T2.column2;

References

• Code sample here: GROUP BY in UPDATE FROM clause
• And here
• Formal Syntax Specification