Mysql 插入 ... select，获取最后插入 ID

Question

I have this query in php. It's an insert select copying from table2, but I need to get the IDs of the newly created rows and store them into an array. Here is my code:

$sql = "INSERT INTO table1 SELECT distinct * from table2";  
$db->query($sql);

I could revert the flow starting with a select on table2 and making all single inserts but it would slow down the script on a big table. Ideas?

Answer 1

You could lock the table, insert the rows, and get the ID of the last item inserted, and then unlock; that way you know that the IDs will be contiguous as no other concurrent user could have changed them. Locking and unlocking is something you want to use with caution though.

An alternative approach could be to use one of the columns in the table - either an 'updated' datetime column, or an insert-id column (for which you put in a value that will be the same across all of your rows.)
That way you can do a subsequent SELECT of the IDs back out of the database matching either the updated time or your chosen insert ID.