Question

Consider this two tables :

tbl 1

Qsno      City  Status  Year    Month
--------------------------------------
1          01     3      1990     1
2          01     3      1990     1
1          02     3      1990     2
2          02     3      1990     2
1          03     3      1990     1
2          03     1      1990     1
3          03     1      1990     1

and :

tbl 2

Qsno      City  
---------------
 1          01   
 2          01   
 1          03   
 2          03   
 3          03   

Qsno + City are unique

Ok, I want to update row from tbl1 that has row in tbl2 and set Month = 3.

How I can do this?

thanks

Answer 1

update tbl1
set Month = 3
where exists
  (select *
   from tbl2
   where tbl1.Qsno = tbl2.Qsno and
         tbl1.City = tbl2.City)