Question

I have columns in mysql

id, unique_guid, attribute1, ..., create_time, update_time

for a table.

I want to create a record if it has never been created with create_time, or if it has been created, just replace some/all attributes and update_time. I am using Java, and using mysql connector.

Is there a way I can do this without querying for existence of the record and then updating it, ending up in two queries?

PS: Note that create_time, update_time are not mysql “timestamps”, they are “datetime.”

Thanks!

Answer 1

Use ON DUPLICATE KEY UPDATE: http://dev.mysql.com/doc/refman/5.6/en/insert-on-duplicate.html

It’s MySQL specific, but it will do what you are asking.