Is MySQL_insert_id Reliable for Multi-Row Inserts?

Is MySQL_insert_id Reliable in Multi-Row Insert Scenarios?

MySQL_insert_id returns the last inserted ID from an INSERT statement. When a website performs numerous row insertions per second, the concern arises whether this function can accurately retrieve the ID of the specific row a particular INSERT query refers to.

Guaranteed Sequence for Each Connection

The MySQL documentation clarifies that the last inserted ID is maintained on a per-connection basis. Hence, the ID returned for a given client is the first auto-incremented value generated for the most recent statement affecting an auto-increment column by that client.

Client Isolation

Importantly, this value is not affected by other clients, even if they generate their own auto-increment values. This isolation mechanism ensures that each client can retrieve its unique ID without any conflicts or the need for locking or transactions.

Safe to Use

In summary, the MySQL_insert_id function is safe to use in scenarios where multiple rows are being inserted per second. Its per-connection design ensures that each client can correctly retrieve its own IDs without any ambiguity or interference from other clients.

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