I am using PHP with MySQL.

I just want to create a contact page but I got this error : Variable “contactForm” does not exist when Im sure that I render the variable to the twig page.

I got this error when I try to save an approvement(which has variables : products, name_client and number) to the database

I want to print a variable with PersistentCollection Type (products)
I made a for loop but I got this error
Object of class AppEntityProduct could not be converted to string

I have a purchase table which contains a list of products selected but they are in collection type
I want to print them in twig
when I did a for loop, I got nothing as you can see in the pictures below.

Why when I want to use the method $user->getEmail() to make the email in the current session.

I got this error when I go to /products/purchases to get the list of all my purchases but I got this error
Object of class DoctrineORMPersistentCollection could not be converted to string

I have user, position and unit table.
If I use select distinct, the result does not contain any column of position and unit: