Handle null values in BULK COLLECT - oracle

Question

I trying to pass data from table A to table B, but first I need to check if the data I'm trying to insert is not in the table B. I do this with a query if exists will return the identification. The problem is the second execution throws a unique constraint violation so it appears the validation to compare if exist in table B is not working, or the condition in the if statement is wrong.
DECLARE
LN_EXIST NUMBER;
CURSOR cur
IS
SELECT *
FROM table_A
TYPE cur_aat IS TABLE OF cur%ROWTYPE
INDEX BY PLS_INTEGER;
cur_rows cur_aat;
BEGIN
OPEN cur;
LOOP
FETCH cur BULK COLLECT INTO cur_rows LIMIT 1000;
EXIT WHEN cur%NOTFOUND; /* cause of missing rows */
FOR I IN 1 .. cur_rows.COUNT
LOOP
LN_EXIST := 0;
BEGIN
DBMS_OUTPUT.put_line (cur_rows (I).PEU_IDENTIFICACION);
SELECT PUV.PEU_IDENTIFICACION -- check
INTO LN_EXIST
FROM table_b PUV
WHERE (CASE
WHEN PUV.PEU_IDENTIFICACION =
cur_rows (I).PEU_IDENTIFICACION
AND NVL (PUV.PEU_PRIMER_NOMBRE, '0') =
NVL (cur_rows (I).PEU_PRIMER_NOMBRE, '0')
AND NVL (PUV.PEU_SEGUNDO_NOMBRE, '0') =
NVL (cur_rows (I).PEU_SEGUNDO_NOMBRE, '0')
AND PUV.PEU_PRIMER_APELLIDO =
cur_rows (I).PEU_PRIMER_APELLIDO
AND NVL (PUV.PEU_SEGUNDO_APELLIDO, '0') =
NVL (cur_rows (I).PEU_SEGUNDO_APELLIDO,
'0')
AND PUV.PEU_FECHA_NACIMIENTO =
cur_rows (I).PEU_FECHA_NACIMIENTO
THEN
'S'
ELSE
'N'
END) = 'S';
EXCEPTION
WHEN OTHERS
THEN
LN_EXIST:= 0;
END;
IF LN_EXIST!= 0 --if not exist
THEN
INSERT
INTO table_b (PEU_ID,
PEU_IDENTIFICACION,
PEU_PRIMER_APELLIDO,
PEU_SEGUNDO_APELLIDO,
PEU_PRIMER_NOMBRE,
PEU_SEGUNDO_NOMBRE,
)
VALUES (cur_rows (I).PEU_ID,
cur_rows (I).PEU_TIPO_IDENTIFICACION,
cur_rows (I).PEU_IDENTIFICACION,
cur_rows (I).PEU_PRIMER_APELLIDO,
cur_rows (I).PEU_SEGUNDO_APELLIDO,
cur_rows (I).PEU_PRIMER_NOMBRE,
cur_rows (I).PEU_SEGUNDO_NOMBRE,
);
END IF;
END LOOP;
EXIT WHEN cur%NOTFOUND;
END LOOP;
COMMIT;
CLOSE cur;
END;

Answer 1

First of all, the code shown above won't execute because of syntax errors in the lines which read
PEU_SEGUNDO_NOMBRE,
and
cur_rows (I).PEU_SEGUNDO_NOMBRE,
The trailing commas will cause the compilation to fail.
Second, row-by-row processing tends to be slow, even when you bulk collect the data into memory from the database. I suggest you use a MERGE, which replaces your cursor-and-loop logic with a single statement:
MERGE INTO TABLE_B b
USING TABLE_A a
ON (b.PEU_IDENTIFICACION = a.PEU_IDENTIFICACION AND
NVL(b.PEU_PRIMER_NOMBRE, '0') = NVL (a.PEU_PRIMER_NOMBRE, '0') AND
NVL (b.PEU_SEGUNDO_NOMBRE, '0') = NVL(a.PEU_SEGUNDO_NOMBRE, '0') AND
b.PEU_PRIMER_APELLIDO = a.PEU_PRIMER_APELLIDO AND
NVL(b.PEU_SEGUNDO_APELLIDO, '0') = NVL(a.PEU_SEGUNDO_APELLIDO, '0') AND
b.PEU_FECHA_NACIMIENTO = a.PEU_FECHA_NACIMIENTO)
WHEN NOT MATCHED THEN
INSERT (PEU_ID,
PEU_IDENTIFICACION,
PEU_PRIMER_APELLIDO,
PEU_SEGUNDO_APELLIDO,
PEU_PRIMER_NOMBRE,
PEU_SEGUNDO_NOMBRE)
VALUES (a.PEU_ID,
a.PEU_TIPO_IDENTIFICACION,
a.PEU_IDENTIFICACION,
a.PEU_PRIMER_APELLIDO,
a.PEU_SEGUNDO_APELLIDO,
a.PEU_PRIMER_NOMBRE,
a.PEU_SEGUNDO_NOMBRE);
Best of luck.

Answer 2

I checked, instead of use a select statement only, i added a count statement, to determine the total of coincidences that exist with the parameters i set so all the times will return a value if not exist 0 and if exist other value than 0.
DECLARE
LN_EXIST NUMBER;
CURSOR cur
IS
SELECT *
FROM table_A
TYPE cur_aat IS TABLE OF cur%ROWTYPE
INDEX BY PLS_INTEGER;
cur_rows cur_aat;
BEGIN
OPEN cur;
LOOP
FETCH cur BULK COLLECT INTO cur_rows LIMIT 1000;
EXIT WHEN cur%NOTFOUND; /* cause of missing rows */
FOR I IN 1 .. cur_rows.COUNT
LOOP
DBMS_OUTPUT.put_line (cur_rows (I).PEU_IDENTIFICACION);
SELECT COUNT (PUV.PEU_IDENTIFICACION) -- check
INTO LN_EXIST
FROM table_b PUV
WHERE (CASE
WHEN PUV.PEU_IDENTIFICACION =
cur_rows (I).PEU_IDENTIFICACION
AND NVL (PUV.PEU_PRIMER_NOMBRE, '0') =
NVL (cur_rows (I).PEU_PRIMER_NOMBRE, '0')
AND NVL (PUV.PEU_SEGUNDO_NOMBRE, '0') =
NVL (cur_rows (I).PEU_SEGUNDO_NOMBRE, '0')
AND PUV.PEU_PRIMER_APELLIDO =
cur_rows (I).PEU_PRIMER_APELLIDO
AND NVL (PUV.PEU_SEGUNDO_APELLIDO, '0') =
NVL (cur_rows (I).PEU_SEGUNDO_APELLIDO,
'0')
AND PUV.PEU_FECHA_NACIMIENTO =
cur_rows (I).PEU_FECHA_NACIMIENTO
THEN
'S'
ELSE
'N'
END) = 'S';
IF LN_EXIST!= 0 --if not exist
THEN
INSERT
INTO table_b (PEU_ID,
PEU_IDENTIFICACION,
PEU_PRIMER_APELLIDO,
PEU_SEGUNDO_APELLIDO,
PEU_PRIMER_NOMBRE,
PEU_SEGUNDO_NOMBRE,
)
VALUES (cur_rows (I).PEU_ID,
cur_rows (I).PEU_TIPO_IDENTIFICACION,
cur_rows (I).PEU_IDENTIFICACION,
cur_rows (I).PEU_PRIMER_APELLIDO,
cur_rows (I).PEU_SEGUNDO_APELLIDO,
cur_rows (I).PEU_PRIMER_NOMBRE,
cur_rows (I).PEU_SEGUNDO_NOMBRE,
);
END IF;
END LOOP;
EXIT WHEN cur%NOTFOUND;
END LOOP;
COMMIT;
CLOSE cur;
END;