Assuming that we have 2 tables - customers and orders:
Which SELECT statement brings both the customers with and those without an order?

Question

Assuming that we have 2 tables - customers and orders:  
 Which SELECT statement brings both the customers with and those without an order?

Answer

select * from customers left join orders on orders.customer_id = customers.customer_id where orders.order_id is not null;

Answer

select * from customers join orders on orders.customer_id = customers.customer_id;

Answer

select * from customers left join orders on orders.customer_id = customers.customer_id;

Answer

select * from customers left join orders on orders.customer_id = customers.customer_id where orders.order_id is null;

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