Question

I have a requirement to update a record if it exists else insert it. I know this has been asked a few times but I think my problem is a bit trickier.

I have a table (tbl_settings):

setting_id   |    token   |   setting_value   |   setting_for
1                 1           on                  background
2                 1           off                 vibrate
3                 2           on                  vibrate

etc

This is for a mobile app which I will save the users settings in a remote DB so the can retrieve later if needed.

Setting_id is unique and auto increment.

Token is going to be the devices token id (user specific)

Setting_value is the value (on/off) for that particular setting

Setting_for is the name of the actual setting

Now there are 4 setting options available to a user which can be written to the DB at individual times (when the user changes the setting on/off) or together if its better.

So if the user changes the vibrate setting, I need a query to check if vibrate and token exist update that particular record otherwise insert with token, setting_value and setting_for.

Hopefully its possible in a single query. If not I will just use multiple queries, one to check if it exists and the other to insert or update.

Answer 1

MySQL offers two options for this:

• replace into
• insert ... on duplicate update

Do note that in both cases you’ll have to drop your setting_id (which seems pointless anyway) and use a composite primary key.