PL/SQL how to display data from select statement inside procedure? - sql

Question

I am not sure how to display my select statement in my procedure. This is my code inside my procedure:
CREATE OR REPLACE PROCEDURE numberOfSupplier (X INT:=0)
AS
rName REGION.R_NAME%TYPE;
nName NATION.N_NAME%TYPE;
sNKeyC SUPPLIER.S_NATIONKEY%TYPE;
BEGIN
FOR rec IN(
SELECT R.R_NAME, N.N_NAME, COUNT(S.S_NATIONKEY)
INTO rName, nName, sNKeyC
FROM REGION R, NATION N, SUPPLIER S
WHERE R.R_REGIONKEY = N.N_REGIONKEY
AND S.S_NATIONKEY = N.N_NATIONKEY
GROUP BY R.R_NAME, N.N_NAME
HAVING COUNT(S.S_NATIONKEY) > X)
LOOP
dbms_output.put_line('R_NAME'||rName);
dbms_output.put_line('N_NAME'||nName);
dbms_output.put_line('COUNT(S_NATIONKEY)'||sNKeyC);
END LOOP;
END;
/
--executing numberOfSupplier
EXECUTE numberOfSupplier(130);
This is what I get, which has no errors but not what I want:
SQL> EXECUTE numberOfSupplier(130);
R_NAME
N_NAME
COUNT(S_NATIONKEY)
R_NAME
N_NAME
COUNT(S_NATIONKEY)
R_NAME
N_NAME
COUNT(S_NATIONKEY)
R_NAME
N_NAME
COUNT(S_NATIONKEY)
What I want to get is this:
R_NAME N_NAME COUNT(S.S_NATIONKEY)
------------------------- ------------------------- --------------------
ASIA INDONESIA 131
ASIA CHINA 145
MIDDLE EAST SAUDI ARABIA 132
EUROPE GERMANY 132
I am able to get the above result if I just execute the select statement, however I dont know how to put this select statement in my procedure and get the table above:
SELECT R.R_NAME, N.N_NAME, COUNT(S.S_NATIONKEY)
FROM REGION R, NATION N, SUPPLIER S
WHERE R.R_REGIONKEY = N.N_REGIONKEY
AND S.S_NATIONKEY = N.N_NATIONKEY
GROUP BY R.R_NAME, N.N_NAME
HAVING COUNT(S.S_NATIONKEY) > 130;
Can someone explain to me why and how to fix this. Thankyou very much.

Answer 1

Put headers out of the loop and then, in the loop, concatenate all values you'd want to display. Use RPAD to nicely align values.
Apart from that, you misused FOR loop; you don't select INTO within its select statement, but use cursor variable. I don't have your tables so I used Scott's, for illustration:
SQL> CREATE OR REPLACE PROCEDURE numberOfSupplier (X INT:=0)
2 AS
3 BEGIN
4 dbms_output.put_line(rpad('R_NAME', 15, ' ') ||
5 rpad('N_NAME', 15, ' ') ||
6 'COUNT(S_NATIONKEY)'
7 );
8 dbms_output.put_line(rpad('-', 14, '-') || ' ' ||
9 rpad('-', 14, '-') || ' ' ||
10 rpad('-', 14, '-'));
11 FOR rec IN(
12 SELECT d.dname R_NAME,
13 e.ename N_NAME,
14 COUNT(*) snkeyc
15 FROM emp e join dept d on e.deptno = d.deptno
16 where e.deptno = 10
17 group by d.dname, e.ename
18 )
19 loop
20 dbms_output.put_line(rpad(rec.r_name, 15, ' ') ||
21 rpad(rec.n_name, 15, ' ') ||
22 rec.sNKeyC
23 );
24 END LOOP;
25 END;
26 /
Procedure created.
Testing:
SQL> set serveroutput on
SQL> exec numberofsupplier;
R_NAME N_NAME COUNT(S_NATIONKEY)
-------------- -------------- --------------
ACCOUNTING KING 1
ACCOUNTING CLARK 1
ACCOUNTING MILLER 1
PL/SQL procedure successfully completed.
SQL>

Answer 2

Changing your code slightly and using cursors instead must do your job.
create or replace PROCEDURE numberOfSupplier (X INT:=0)
AS
CURSOR rec IS SELECT R.R_NAME, N.N_NAME, COUNT(S.S_NATIONKEY) counter
FROM REGION R, NATION N, SUPPLIER S
WHERE R.R_REGIONKEY = N.N_REGIONKEY
AND S.S_NATIONKEY = N.N_NATIONKEY
GROUP BY R.R_NAME, N.N_NAME
HAVING COUNT(S.S_NATIONKEY) > X; -- cursor to collect all the Objects
BEGIN
dbms_output.put_line('R_NAME'||CHR(9)||'N_NAME'||CHR(9)||'COUNT(S_NATIONKEY)');
dbms_output.put_line('--------------------------------------------------');
FOR rec_obj IN rec LOOP
dbms_output.put_line(rec_obj.R_NAME||CHR(9)||CHR(9)||rec_obj.N_NAME||CHR(9)||CHR(9)||rec_obj.counter);
END LOOP;
EXCEPTION -- exception handlers begin
WHEN no_data_found THEN --catches exception when No Data Found
dbms_output.put_line('No Data Found');
WHEN TOO_MANY_ROWS THEN -- More than 1 row seleced
dbms_output.put_line('More than 1 row seleced');
WHEN OTHERS THEN -- handles all other errors
ROLLBACK;
dbms_output.put_line('I AM HERE!!!'
|| sqlcode
|| ' '
|| sqlerrm);
END;
/