Insert into a MySQL table or update if exists

Question

I want to add a row to a database table, but if a row exists with the same unique key I want to update the row.

For example:

INSERT INTO table_name (ID, NAME, AGE) VALUES(1, "A", 19); 

Let’s say the unique key is ID, and in my Database, there is a row with ID = 1. In that case, I want to update that row with these values. Normally this gives an error.
If I use INSERT IGNORE it will ignore the error, but it still won’t update.

Answer 1

Use INSERT ... ON DUPLICATE KEY UPDATE

QUERY:

INSERT INTO table (id, name, age) VALUES(1, "A", 19) ON DUPLICATE KEY UPDATE     name="A", age=19