Output of Duplicats using a Procedure - sql

Question

i am in the middle of studys and currently doing some exercises.
I am trying to make procedure that shows how many duplicats are in a row.
CREATE OR REPLACE PROCEDURE anzahl1(
tabelle VARCHAR2,
reihe VARCHAR2,
wieviel OUT NUMBER
)AS
test VARCHAR2(4000);
BEGIN
EXECUTE IMMEDIATE 'SELECT
reihe,
(COUNT(*)-1) AS Anzahl
INTO
wieviel
FROM
tabelle
GROUP BY
reihe
HAVING COUNT(*) > 1' using out wieviel;
DBMS_OUTPUT.PUT_LINE(wieviel);
END;
/
i tried many things but nothing worked...
even the result i was given by a teacher of my old school didnt work:
CREATE OR REPLACE PROCEDURE check_doppelte_Werte_p (
p_tabellenname IN USER_TAB_COLUMNS.TABLE_NAME%TYPE,
p_spaltenname IN USER_TAB_COLUMNS.COLUMN_NAME%TYPE,
p_ergebnis BOOLEAN
) OUT
IS
v_dummy NUMBER := 1;
v_sql_anweisung varchar2 (4000);
BEGIN
v_sql_anweisung :=
'SELECT MAX(COUNT ('
|| p_spaltenname
|| ')) '
|| ' FROM '
|| p_tabellenname
|| ' GROUP BY '
|| p_spaltenname;
DBMS_OUTPUT.PUT_LINE (v_sql_anweisung);
EXECUTE IMMEDIATE v_sql_anweisung INTO v_dummy;
IF v_dummy > 1 THEN
DBMS_OUTPUT.PUT_LINE( 'Die Tabelle '
|| 'hat mindestens '
|| TO_CHAR (V_DUMMY)
|| ' doppelte Werte in der Spalte '
|| p_spaltenname);
p_ergebnis := TRUE;
ELSE
p_ergebnis := FALSE;
END IF;
EXCEPTION
-- Keine Werte gefunden, da
WHEN NO_DATA_FOUND
THEN
p_ergebnis := FALSE;
DBMS_OUTPUT.PUT_LINE ('Tabellenname oder Spaltenname sind nicht vorhan-
den!!!');
END;
What would you do/change?

Answer 1

Your code doesn't substitute the variables in the dynamic sql.The query String has been to be appended with the input variables.
Please try the code below,
CREATE OR REPLACE PROCEDURE anzahl1(
tabelle VARCHAR2,
reihe VARCHAR2,
wieviel OUT NUMBER
)AS
test VARCHAR2(4000);
lv_query VARCHAR2(4000);
BEGIN
lv_query := 'SELECT (COUNT(*)-1) cnt FROM '||tabelle ||' GROUP BY '||reihe||' HAVING COUNT(*) > 1';
EXECUTE IMMEDIATE lv_query into wieviel;
DBMS_OUTPUT.PUT_LINE(wieviel);
EXCEPTION
WHEN OTHERS THEN
DBMS_OUTPUT.PUT_LINE('ERROR '||SQLCODE||' '||SUBSTR(SQLERRM,1,200));
END;
/
I create table and populate records as below,
CREATE TABLE EMP(ID NUMBER(10),NAME VARCHAR2(40));
INSERT INTO EMP VALUES (1, 'TEST');
INSERT INTO EMP VALUES (1, 'TEST');
INSERT INTO EMP VALUES (2, 'TEST2');
Now i call the stored procedure to test for EMP table for ID column,
declare
lv_cnt number(10);
begin
anzahl1('EMP','ID',lv_cnt);
dbms_output.put_line(lv_cnt);
end;
This give output as ,
1