What conditions are necessary for lastInsertId to work

Question

I'm trying to wrap my head around PDO. How come $lastid doesn't output anything?

function renderRoot($db){
    $sql = "INSERT INTO nodes (name) VALUES ('/');";
    $response = $db->query($sql);
    $lastid = $db->lastInsertId();
    echo $lastid;
    return;
}

The code adds a value to the table and it has an column called id, that aoutincrements.

Here is my sql(postgresql):

$nodetable = "create table nodes (
    id serial primary key,
    parentid integer references nodes(id ),
    name varchar
);";

Does the table have an auto-increment column? Did the insert succeed? — Barmar, Nov 13 '13 at 16:41
the inser succeeded. I'll updated the question with the sql. — Himmators, Nov 13 '13 at 16:42
Use `INSERT ... RETURNING ...` instead. This `lastInsertId` stuff is modeled after mysql and not the best choice with postgres. — Daniel Vérité, Nov 13 '13 at 18:37

score 0 · Accepted Answer · answered Nov 14 '13 at 11:23

0

In postgresql, lastInsertId() take an argument, in your case, the name of the sequence, i.e. nodes_id_seq

$lastid = $db->lastInsertId('nodes_id_seq');

Otherwise it will return the last oid, if any.

answered Nov 14 '13 at 11:23

Cefull Lo

91
2

worht noting is that nodes is my database and id is the column. Thanks! – Himmators Nov 14 '13 at 13:16

What conditions are necessary for lastInsertId to work

1 Answers1