Does MySQL_Insert_ID Work Reliably With Multiple Concurrent Inserts?

Can MySQL_Insert_ID Handle Multiple Concurrent Inserts?

The PHP function mysql_insert_id retrieves the last inserted ID from a MySQL table. When working with high-traffic websites that frequently insert data into the database, it becomes crucial to ensure that mysql_insert_id provides accurate results despite multiple concurrent inserts.

MySQL's Internal ID Management

According to the MySQL documentation, the last inserted ID is maintained on a per-connection basis. This means that the value returned by mysql_insert_id for a specific connection corresponds to the first auto-increment value generated by the most recent statement affecting an auto-increment column by that connection.

Concurrency and ID Retrieval

The MySQL manual states that "this value cannot be affected by other clients, even if they generate AUTO_INCREMENT values of their own." This behavior guarantees that each connection can retrieve its ID without interference from other connections, even if they are concurrently generating their own auto-increment values.

Conclusion

Based on this information, it is safe to use mysql_insert_id in scenarios where multiple concurrent inserts are occurring. MySQL's internal mechanisms ensure that each connection receives the correct ID generated by its own INSERT query. This allows for accurate tracking of inserted data, even in high-traffic environments.

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