Need to validate data in parent table PL/SQL [closed] - oracle

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I have created two tables A and B with Table A as parent table and Table B as child table having foreign key constraint with Table A.
Following are the contents of Table A
CUS_ID NAME
1 MICHAEL
2 SANDRO
3 ROBERT
Following are the contents of Table B
CUS_ID ORDER
2 PIZZA
3 BURGER
I will get input data in following format to insert in to the above mentioned tables.
NAME ORDERS
SANDRO BURGER
ROBERT PIZZA
I am trying to create a pl/sql procedure to insert data into Table B after validating data in parent table Table A.
scenario 1: If data is available in parent table Table A and then insert data only in Table B.
scenario 2: If data is not available in Parent Table Table A, then insert NAME in to Table A and then insert ORDER data into Table B.
For scenario 2, i am able to achieve it using the following pl/sql code
INSERT INTO TABLE_A (cus_id, name)
VALUES (cus_seq.NEXTVAL, NAME)
RETURNING cus_id INTO l_cus_id;
INSERT INTO TABLE_B (cus_id, order)
VALUES (order_seq.NEXTVAL, l_cus_id, ORDER);
I need help in achieving scenario 1. Even I will look forward to other suggestion in achieving both the scenarios in optimum way.

Answer 1

You need to encapsulate the lookup of table_a in a sub-routine.
create or replace procedure place_order
( p_name table_a.name%type
, p_order table_b.order&type )
is
l_cus_id table_a.cus_id%type;
function get_cus_id
( p_name table_a.name%type )
return table_a.cus_id%type
is
return_value table_a.cus_id%type;
begin
begin
select cus_id into return_value
from table_a
where name = p_name;
exception
when no_data_found then
insert into table_a (cus_id, name)
values (cus_seq.nextval, p+name)
returning cus_id into return_value;
end;
return return_value;
end get_cus_id;
begin
l_cus_id := get_cus_id(p_name);
insert into table_b (cus_id, order)
values (l_cus_id, order);
end place_order;

Answer 2

Try this approach
BEGIN
SELECT cus_id INTO l_cus_id
FROM table_a
WHERE table_a.name = l_cust_name;
EXCEPTION
WHEN NO_DATA_FOUND THEN
INSERT INTO TABLE_A (cus_id, name)
VALUES (cus_seq.NEXTVAL, l_cust_name)
RETURNING cus_id INTO l_cus_id;
END;
INSERT INTO table_b (ord_id, cus_id, "ORDER")
VALUES (order_seq.NEXTVAL, l_cus_id, l_order);

Answer 3

Can try this
CREATE or REPLACE procedure place_order
( p_name table_a.name%type
, p_order table_b.order&type )
is
v_cnt number;
BEGIN
SELECT count(name) into v_cnt from a where name=p_name;
INSERT into table_b values(p_name,p_order);
EXCEPTION
when NO_DATA_FOUND
insert into table_a values (cus_seq.nextval,p_name);
insert into table_b values(p_name,p_order);
END;