Insert data on two tables using foreign key mysql php - php

Question

Table user:
- user_id
- user_name
- (other info fields that doesn't matter for
Table item:
- item_id
- item_name
- (other info fields that doesn't matter for now)
All fields on the attached picture are from ITEM table but the last one that says "Colaborador"
Update:
Sorry,
The point is this:
I have 2 tables, Items and Users
And I want to register Electronic equipment on Items table (for example if I buy a cellphone I want to register it on that table) and then, that item (cellphone on this case) will be attributed to an user, and to do that register of the item attributed to the user I need to match the 2 tables with a foreign key that I already have, but the point is, I don't want to input the user_id (that is the foreign key), but I want to input the user NAME
Hope I make myself clear this time
PHP Code
if ($valid) {
$pdo = Database::connect();
$pdo->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
$sql = "INSERT INTO ativos (item,comentario,data_aquisicao,localizacao,fabricante,modelo,anexo_a,numero_serie,imei,ativo_sap,evento,data_entrega,data_devolucao,data_estravio,id_user) values(?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)";
$q = $pdo->prepare($sql);
$q->execute(array($item,$comentario,$data_aquisicao,$localizacao,$fabricante,$modelo,$anexo_a,$numero_serie,$imei,$ativo_sap,$evento,$data_entrega,$data_devolucao,$data_estravio,$id_user));
Database::disconnect();
header("Location: index.php");
}

Answer 1

Without seeing how your PHP code generates your associated MySQL queries, we can't possibly tell you how to re-factor your specific case to achieve this functionality.
On a more generic level, you'd probably have to pass the username from the input form into a subquery as part of your INSERT statement:
INSERT INTO `item` (item_id, item_name, owner_id)
VALUES (1, 'abcdef', (SELECT user_id FROM user WHERE user_name = 'user1'))
Edit after OP edit to add PHP code:
Just refactor your $sql string query to include the subquery:
$sql = "INSERT INTO ativos (item,comentario,data_aquisicao,localizacao,fabricante,modelo,anexo_a,numero_serie,imei,ativo_sap,evento,data_entrega,data_devolucao,data_estravio,id_user) values(?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, (SELECT user_id FROM user WHERE user_name = ?))";
... which should return the user_id associated with a particular user_name and insert the ID value to the record.