INSERT OR UPDATE if record already exists MySQL

Question

I need to write a MySQL query for insert or update some fields. I've seen about the ON DUPLICATE KEY , but my fields are not PRIMARY KEY or UNIQUE , only the combination is unique. Here is the fields list:

ID (PRIMARY KEY AUTOINCREMENT BIGINT), user (BIGINT), creator (BIGINT), type (TINYINT), value (BIGINT), date (INT), readed (TINYINT), erased (TINYINT).

The table name is notifications (if it can be useful). I need to insert a new record or update the existent one if the user, creator, type, values are all the same of the values to insert (so like AND ). How I can do that?

Answer 1

You can create a unique index on the variable. I'm not sure which are the variables in question, but here is an example:

create unique index idx_table_user_creator_type on table(user, creator, type)

You can also do this in the create table statement as well, using the syntax for a unique constraint.

You would then use the constraint as:

insert into table(user, creator, type, col1, . . .)
    values(@user, @creator, @type, . . .)
    on duplicate key update col1 = values(col1),
                            col2 = values(col2),
                            . . . ;