"single-row subquery returns more than one row" three table

Question

I'm having problems when entering payroll data into a column.

Table AA

ID_USER      PERIOD          SALARY          

1001        1-MAY-2012         ?
1002        1-MAY-2012         ?
1001        1-JUN-2012         ?
1002        1-JUN-2012         ?

Table BB

  ID_USER      Name          ID_SALARY           

1001        Rayker          1
1002        Jones           2
1003        Wiliam          2

Table CC

    ID_SALARY    SALARY             

  1          $50          
  2          $60 

Here's my script:

UPDATE "AA" A 
SET A.SALARY = (select C.SALARY from "BB" B,"CC" C where B.ID_SALARY=C.ID_SALARY)
WHERE EXISTS( SELECT B.ID_USER FROM "AA" A, "BB" B  WHERE A.ID_USER = B.ID_USER )
ORDER BY A.ID_USER

Answer 1

this must be enough

UPDATE "AA" A 
SET A.SALARY = (select C.SALARY from "BB" B,"CC" C where B.ID_SALARY=C.ID_SALARY AND B.ID_USER = A.ID_USER)