Oracle INSERT, SELECT and NOT EXISTS - sql

Question

I have a procedure, which is working fine. There are times when the same VALUES are passed into the procedure and generates a unique KEY violation.
I know this could be easily solved by using
the usual solutions of either
LOG ERRORS INTO
clause, or to use the
/*+ ignore_row_on_dupkey_index ... */
I saw this link and was trying to implement #OMG Ponies NOT EXISTS solution by seeing if the VALUES are already in the PRIMARY KEY but after hours of research and trying different methods I was unsuccessful
Avoid duplicates in INSERT INTO SELECT query in SQL Server
I'm very curious to see how this solution could be implemented in my situation.
Thanks in advance to all who respond and for your help, patience and expertise.
My working test CASE is below (not modified) is below. BTW im testing in live SQL in case anyone wants to use the same environment.
ALTER SESSION SET NLS_DATE_FORMAT = 'MMDDYYYY HH24:MI:SS';
create table schedule(
seq_num NUMBER GENERATED BY DEFAULT AS IDENTITY (START WITH 1) NOT NULL,
schedule_id NUMBER(4),
location_id number(4),
base_date DATE,
start_date DATE,
end_date DATE,
constraint schedule_pk primary key (schedule_id, location_id, base_date),
CONSTRAINT start_min check (start_date=trunc(start_date,'MI')),
CONSTRAINT end_min check (end_date=trunc(end_date,'MI')),
CONSTRAINT end_gt_start CHECK (end_date >= start_date)
);
/
CREATE TABLE locations AS
SELECT level AS location_id,
'Door ' || level AS location_name,
CASE round(dbms_random.value(1,3))
WHEN 1 THEN 'A'
WHEN 2 THEN 'T'
WHEN 3 THEN 'G'
END AS location_type
FROM dual
CONNECT BY level <= 15;
ALTER TABLE locations
ADD ( CONSTRAINT locations_pk
PRIMARY KEY (location_id));
CREATE OR REPLACE PROCEDURE CREATE_SCHEDULE
(
i_schedule_id IN PLS_INTEGER,
i_base_date IN DATE,
i_offset IN PLS_INTEGER DEFAULT 0,
i_incr IN PLS_INTEGER DEFAULT 10,
i_duration IN PLS_INTEGER DEFAULT 5
)
AS
l_offset interval day to second;
l_incr interval day to second;
l_duration interval day to second;
BEGIN
l_offset :=
NUMTODSINTERVAL(i_offset, 'SECOND') ;
l_incr :=
NUMTODSINTERVAL(i_incr, 'MINUTE') ;
l_duration :=
NUMTODSINTERVAL(i_duration, 'MINUTE') ;
INSERT INTO schedule(
schedule_id
,location_id
,base_date
,start_date
,end_date
)
SELECT i_schedule_id
, l.location_id
, i_base_date
, i_base_date + l_offset
+ (l_incr * (ROWNUM - 1)) AS start_date
, i_base_date + l_offset
+ (l_incr * (ROWNUM - 1))
+ l_duration AS end_date
FROM locations l;
END;
/
EXEC CREATE_SCHEDULE(1,TRUNC(SYSDATE))

Answer 1

Use a MERGE statement:
CREATE OR REPLACE PROCEDURE CREATE_SCHEDULE(
i_schedule_id IN PLS_INTEGER,
i_base_date IN DATE,
i_offset IN PLS_INTEGER DEFAULT 0,
i_incr IN PLS_INTEGER DEFAULT 10,
i_duration IN PLS_INTEGER DEFAULT 5
)
AS
l_offset interval day to second;
l_incr interval day to second;
l_duration interval day to second;
BEGIN
l_offset := NUMTODSINTERVAL(i_offset, 'SECOND') ;
l_incr := NUMTODSINTERVAL(i_incr, 'MINUTE') ;
l_duration := NUMTODSINTERVAL(i_duration, 'MINUTE') ;
MERGE INTO schedule dst
USING (
SELECT i_schedule_id AS schedule_id,
l.location_id,
i_base_date AS base_date,
i_base_date + l_offset + (l_incr * (ROWNUM - 1))
AS start_date,
i_base_date + l_offset + (l_incr * (ROWNUM - 1)) + l_duration
AS end_date
FROM locations l
) src
ON ( src.schedule_id = dst.schedule_id
AND src.location_id = dst.location_id
AND src.base_date = dst.base_date
)
WHEN NOT MATCHED THEN
INSERT (
schedule_id,
location_id,
base_date,
start_date,
end_date
) VALUES (
src.schedule_id,
src.location_id,
src.base_date,
src.start_date,
src.end_date
);
END;
/