(no version information, might be only in CVS)
PDO::lastInsertId --
Returns the ID of the last inserted row
返回值
If a sequence name was not specified for the name
parameter, PDOStatement::lastInsertId() returns a
string representing the row ID of the last row that was inserted into
the database.
If a sequence name was specified for the name
parameter, PDOStatement::lastInsertId() returns a
string representing the next value retrieved from the specified sequence
object.
If the PDO driver does not support this capability,
PDO::lastInsertID() triggers an
IM001 SQLSTATE.