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:

Answer 1

In case, you want to keep old field (For ex: name). The query will be:

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

Answer 2

Just because I was here looking for this solution but for updating from another identically-structured table (in my case website test DB to live DB):

INSERT  live-db.table1
SELECT  *
FROM    test-db.table1 t
ON DUPLICATE KEY UPDATE
        ColToUpdate1 = t.ColToUpdate1,
        ColToUpdate2 = t.ColToUpdate2,
        ...

As mentioned elsewhere, only the columns you want to update need to be included after ON DUPLICATE KEY UPDATE.

No need to list the columns in the INSERT or SELECT, though I agree it's probably better practice.

Answer 3

In my case i created below queries but in the first query if id 1 is already exists and age is already there, after that if you create first query without age than the value of age will be none

REPLACE into table SET `id` = 1, `name` = 'A', `age` = 19

for avoiding above issue create query like below

INSERT INTO table SET `id` = '1', `name` = 'A', `age` = 19 ON DUPLICATE KEY UPDATE `id` = "1", `name` = "A",`age` = 19

may it will help you ...

Answer 4

When using SQLite:

REPLACE into table (id, name, age) values(1, "A", 19)

Provided that id is the primary key. Or else it just inserts another row. See INSERT (SQLite).

Answer 5

Try this:

INSERT INTO table (id,name,age) VALUES('1','Mohammad','21') ON DUPLICATE KEY UPDATE name='Mohammad',age='21'

Note:
Here if id is the primary key then after first insertion with id='1' every time attempt to insert id='1' will update name and age and previous name age will change.