PDO基于lastInsertId（）将新记录插入数据库

Question

Ive just started learning PDO and I'm struggling by simply inserting a new record based from
$lastid = $db->lastInsertId();

The ID gets created in the database table from another function.

But nothing happens when i try to insert a new record based on that ID.

function add_name($last_id, $name) {
    $db = some_db();
    $query = "INSERT INTO team (name) VALUES (:name) WHERE id = '".$last_id."'";
    $stmt = $db->prepare($query);
    $stmt ->bindParam(':name', $name, PDO::PARAM_STR);
    $stmt->execute();
}

Answer 1

INSERT ... WHERE is not valid SQL. If you are inserting a new record, an autoincremnt ID will be generated at that time (if you have such defined for the table).

If you are trying to INSERT a new row into a related table with the last id from another table, then you would set that value as one of your column inputs. So the workflow would look like this:

INSERT [column data for table_a] INTO table_a
[GET autoincrement from last insert]
INSERT (table_a_foreign_key_column, [other table_b columns]) VALUES (table_a_id, [other table_b values) INTO table_b

UPDATE:

Since UPDATE is what you want, you can make update like this:

UPDATE team
SET name = :name
WHERE id = :id

You should use parameters for both name and id values. It is still not clear to me why you would need to make an insert and then an update within the same script execution. It's not like you received any more input from the user that you did not already have. I would guess you could just insert this name values when first creating the record and save yourself the extra trouble of multiple queries.