Mysql: Is it safe to use LastInsertId() ?

No, it is not - the connection pooling by database/sql makes it unsafe. You can use it in transactions, though.

I think he means Result.LastInsertId() which is implemented in result.go#L16 which just uses the insertId variable set in Exec() from the result of the executed statement.

So it's perfectly safe to use concurrently because it's stored in the result and has nothing to do with the connections.

What is NOT safe is executing this after your insert:

SELECT LAST_INSERT_ID()

Because that might use a different connection because of the pooling.

Yeah, thanks. Exactly what @ErikDubbelboer says.

Thanks for the input i did mean Result.LastInsertId()