mysql don't insert if value exists code example

Example 1: insert if not exists mysql

INSERT INTO table_listnames (name, address, tele)
SELECT * FROM (SELECT 'Unknown' AS name, 'Unknown' AS address, '022' AS tele) AS tmp
WHERE NOT EXISTS (
    SELECT name FROM table_listnames WHERE name = 'Rupert'
) LIMIT 1;

Example 2: mysql insert into if not exists

INSERT INTO table_name (firstname, lastname)
SELECT 'NEW FIRSTNAME', 'NEW LASTNAME'
FROM DUAL
WHERE NOT EXISTS(
    SELECT 1
    FROM table_name
    WHERE firstname = 'NEW FIRSTNAME' AND lastname = 'NEW LASTNAME'
)
LIMIT 1;