MySQL Reference Manual :: 24.2.3.33 mysql_insert_id()

my_ulonglong mysql_insert_id(MYSQL *mysql)

Description

Returns the value generated for an AUTO_INCREMENT column by the previous INSERT or UPDATE statement. Use this function after you have performed an INSERT statement into a table that contains an AUTO_INCREMENT field.

More precisely, mysql_insert_id() is updated under these conditions:

Note that mysql_insert_id() returns 0 if the previous statement does not use an AUTO_INCREMENT value. If you need to save the value for later, be sure to call mysql_insert_id() immediately after the statement that generates the value.

The value of mysql_insert_id() is affected only by statements issued within the current client connection. It is not affected by statements issued by other clients.

See Section 12.9.3, “Information Functions”.

Also note that the value of the SQL LAST_INSERT_ID() function always contains the most recently generated AUTO_INCREMENT value, and is not reset between statements because the value of that function is maintained in the server. Another difference is that LAST_INSERT_ID() is not updated if you set an AUTO_INCREMENT column to a specific non-special value.

The reason for the difference between LAST_INSERT_ID() and mysql_insert_id() is that LAST_INSERT_ID() is made easy to use in scripts while mysql_insert_id() tries to provide a little more exact information of what happens to the AUTO_INCREMENT column.

Return Values

Described in the preceding discussion.

Errors

None.