How To solve this pl sql oracle query? - plsql

Question

Write a PL/SQL program using While Loop to display all DEPTNO,DNAME and LOC
from DEPT table. Assuming the difference between two deptno is 10.
I am beginer and i am very confuse to solve this query please help to solve this problem.

Answer 1

Something like this?
SQL> set serveroutput on
SQL> declare
2 i dept.deptno%type; -- loop counter
3 l_max_deptno dept.deptno%type; -- upper limit
4 l_dept_row dept%rowtype; -- will contain the whole DEPT table row
5 begin
6 -- MIN -> i (which will be the starting point); MAX -> l_max_deptno (which will be the end)
7 select min(deptno), max(deptno)
8 into i, l_max_deptno
9 from dept;
10
11 while i <= l_max_deptno
12 loop
13 -- select the whole row into L_DEPT_ROW
14 select *
15 into l_dept_row
16 from dept
17 where deptno = i;
18
19 dbms_output.put_line(l_dept_row.deptno ||' - '||
20 l_dept_row.dname ||' - '||
21 l_dept_row.loc);
22 -- increment counter by 10 (because, as you said, the difference is 10)
23 i := i + 10;
24 end loop;
25 end;
26 /
10 - ACCOUNTING - NEW YORK
20 - RESEARCH - DALLAS
30 - SALES - CHICAGO
40 - OPERATIONS - BOSTON
PL/SQL procedure successfully completed.
SQL>

Answer 2

Here is how you do what you asked for, but bear in mind this is not the optimum way to do it. if your target is to train your self on the While loop in PLSQL, then here you go.
DECLARE
CURSOR C_DEPTS
IS
SELECT DEPTNO, DNAME, LOC FROM DEPT;
V_DEPTNO VARCHAR2 (255);
V_DNAME VARCHAR2 (255);
V_LOC VARCHAR2 (255);
BEGIN
OPEN C_DEPTS;
FETCH C_DEPTS INTO V_DEPTNO, V_DNAME, V_LOC;
WHILE C_DEPTS%FOUND
LOOP
DBMS_OUTPUT.PUT_LINE ('DEPTNO = ' || V_DEPTNO);
DBMS_OUTPUT.PUT_LINE ('DNAME = ' || V_DNAME);
DBMS_OUTPUT.PUT_LINE ('LOC = ' || V_LOC);
FETCH C_DEPTS INTO V_DEPTNO, V_DNAME, V_LOC;
END LOOP;
END;