Question

I have been trying to do insert / update records in a mysql table. Cannot use ON DUPLICATE KEY because i have nothing to do with the primary key.

Basically i have to update a record in the database

INSERT INTO table (city, state, gender, value) VALUES ("delhi","delhi","M",22)

If a record of that city, state, gender exists, then simply overwrite the value.

Can i achieve this without sending two queries from the programming language

Answer 1

actually you can still use ON DUPLICATE KEY, just add a unique index on the following columns, eg

ALTER TABLE tbl_name ADD UNIQUE index_name (city, state, gender)

your query now will be,

INSERT INTO table (city, state, gender, value) 
VALUES ('delhi','delhi','M', 22)
ON DUPLICATE KEY UPDATE value = 22