--Basic Update

UPDATE [TableName]
SET [ColumnName] = [Value]
WHERE [ColumnName] = [Value]

Ex:
UPDATE DEPARTMENT D
SET Empl_Number = (
 SELECT COUNT(EMPL_ID) 
 FROM EMPLOYEE E
 WHERE E.DEPT_ID = D.DEPT_ID
 AND E.ACTIVE=1);

--UPDATE SELECT

UPDATE ([SELECT])
SET [ColumnName] = [Value];

Ex:
UPDATE (SELECT *
      FROM PAYROLL
      WHERE SALARY>60000)
SET TAX = SALARY*0.25;

--Update Multiple column

UPDATE TABLE <alias>
SET <column_name> = ([SELECT][Value]);

UPDATE PAYROLL P1
SET (SALARY,TAX)=
    (SELECT SALARY+250,SALARY*0.42
     FROM PAYROLL P2
   WHERE P2.SALARY>50000 AND P2.SALARY<65000);

-- Update with Returning

UPDATE PAYROLL
SET SALARY = SALARY * 0.52
WHERE SALARY BETWEEN(40000,55000) AND DEPT_ID=1001
RETURNING AVG(SALARY) INTO :ReturnValue;

print ReturnValue;

--Update Table

UPDATE ItEmployee IE SET VALUE(IE) =
(SELECT VALUE(E) FROM EMPLOYEE E WHERE EI.EMPL_ID = E.EMPL_ID)
WHERE IE.EMPL_ID = 1001;

-- Record Update
UPDATE [TableName]
SET ROW = [RecordName];

DECLARE PRrec  PAYROLL%ROWTYPE; 

PRrec.EMPL_ID := 12304;
PRrec.SALARY := 56000;
PRrec.TAX := 2510;
PRrec.VACATION := 12;

UPDATE PAYROLL
SET ROW = PRrec
WHERE EMPL_ID = 12304;