Oracle 18c

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ALTER SESSION SET NLS_DATE_FORMAT = 'YYYY-MM-DD HH24:MI:SS (DY)';
CREATE TABLE city (
  id        NUMERIC(10) PRIMARY KEY,
  city_name VARCHAR(50),
  state     NUMERIC(10),
  district  NUMERIC(10)
);
CREATE TABLE pin_code_master (
  id        NUMERIC(10) PRIMARY KEY,
  picode    NUMERIC(10),
  state     NUMERIC(10),
  district  NUMERIC(10)
);
CREATE TABLE pin_code_temp (
  id        NUMERIC(10) PRIMARY KEY,
  picode    NUMERIC(10),
  state     NUMERIC(10),
  district  NUMERIC(10)
);
INSERT INTO pin_code_master (id, picode, state, district)
SELECT 1, 1, 1, 1 FROM DUAL UNION ALL
SELECT 4, 3, 2, 2 FROM DUAL
2 rows affected

INSERT INTO pin_code_temp (id, picode, state, district)
SELECT 1, 1, 1, 1 FROM DUAL UNION ALL
SELECT 2, 2, 1, 2 FROM DUAL UNION ALL
SELECT 3, 1, 2, 1 FROM DUAL UNION ALL
SELECT 4, 3, 2, 2 FROM DUAL
4 rows affected

INSERT INTO pin_code_master (id, picode, state, district)
SELECT id, picode, state, district
FROM   pin_code_temp t
WHERE  NOT EXISTS (
         SELECT 1
         FROM   pin_code_master m
         WHERE  t.id = m.id       -- Compare primary key columns
                                  -- If you have different primary/unique keys then
                                  -- change the filter and compare those columns.
       )
2 rows affected

SELECT * FROM pin_code_master;


ID
PICODE
STATE
DISTRICT


1
1
1
1

4
3
2
2

2
2
1
2

3
1
2
1