我想知道如何使用内部联接器以其他方式两次选择一列。我的数据库是sqlite,并且我使用PDO db驱动程序。
我的例子:
SELECT orders.id, orders.order_number, clients.first_name, clients.last_name, users.name AS user_name FROM orders INNER JOIN clients ON orders.client_id = clients.id INNER JOIN users ON orders.created_by = users.id
我还想获得编辑此记录的用户名
orders.edited_by = users.id
如何加入此选择?
您将需要使用表别名。
SELECT orders.id, orders.order_number, clients.first_name, clients.last_name, creator.name AS creator_user_name editor.name AS editor_user_name FROM orders INNER JOIN clients ON orders.client_id = clients.id INNER JOIN users creator ON orders.created_by = creator.id INNER JOIN users editor ON orders.edited_by = editor.id