Calling function from another functions: Master and Child functions coding. Here first function receive some parameter(arguments) and those send to another function2 after getting the results of function2 processed within the function1 and return the value to the subprogram.

create or replace function fun1(a number, b number) return number is

big number;

begin

if a>b then

big:=a;

else

big:=b;

end if;

return big;

end;

create or replace function fun2 (a number, b number, c number) return number is

x number;

y number;

begin

x:= fun1 (a,b);

y:=c*x;

return y;

end fun2;

Functions to DML operations for a table: By using function we can operate dml operations with in the database like insertion, deletion and updating.

Example:

Write plsql program to send the parameter as admission and delete it from the stu table.

CREATE OR REPLACE FUNCTION STUDEL(p_admno number) RETURN NUMBER ISBEGIN DELETE FROM STU

WHERE ADMNO=P_ADMNO; COMMIT;

RETURN 1;END;Write plsql program to send the parameter as student details and insert into stu table.

CREATE OR REPLACE FUNCTION STUINSERT(p_admno number, p_sname varchar2, p_course varchar2, p_fee number) return number isBEGIN INSERT INTO STU

VALUES(p_admno,p_sname,p_course,p_fee); COMMIT; RETURN 1;END;

Write plsql program to send the parameter as student admno and fee and fee decreased from the stu table.

CREATE OR REPLACE FUNCTION STUFEEPAY(P_ADMNO NUMBER, P_FEE NUMBER) RETURN NUMBER IS

BEGIN UPDATE STU

SET FEE=FEE-P_FEE

WHERE ADMNO=P_ADMNO; COMMIT; RETURN 1;END;DECLARE

N NUMBER;

BEGIN

N:=STUINSERT(20,'Zeba','Oracle',500);

END;

DECLARE

N NUMBER;

BEGIN

N:=STUDEL(14);

END;

DECLARE

N NUMBER;

BEGIN

N:=STUFEEPAY(13,500);

END;Practice the above similar coding for Books table.