SQL-complete-tutorial

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USE sql_store;
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SELECT 
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	o.order_id,
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    c.first_name
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FROM orders o
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JOIN customers c
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	-- ON o.customer_id = c.customer_id;
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    -- when id columns are named in the same way, we can make the code
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    -- shorter and cleaner by using the USING clause
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    USING (customer_id)
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LEFT JOIN shippers sh
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	USING (shipper_id);
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SELECT *
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FROM order_items oi
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JOIN order_item_notes oin
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	-- ON oi.order_id = oin.order_Id AND
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	-- oi.product_id = oin.product_id;
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	USING (order_id, product_id);
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-- By using the sql_payments database, select the payments and retrieve the following
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-- columns: date, client, amount and name
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USE sql_invoicing;
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SELECT 
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	p.date,
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    c.name AS client,
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    p.amount,
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    pm.name AS 'payment method'
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FROM payments p
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JOIN clients c USING (client_id)
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JOIN payment_methods pm
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	ON pm.payment_method_id = p.payment_method;