MySQL, update multiple tables with one query

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隐瞒了意图╮
隐瞒了意图╮ 2020-11-22 08:00

I have a function that updates three tables, but I use three queries to perform this. I wish to use a more convenient approach for good practice.

How can I update mu

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  •  不要未来只要你来
    2020-11-22 08:31

    Take the case of two tables, Books and Orders. In case, we increase the number of books in a particular order with Order.ID = 1002 in Orders table then we also need to reduce that the total number of books available in our stock by the same number in Books table.

    UPDATE Books, Orders
    SET Orders.Quantity = Orders.Quantity + 2,
        Books.InStock = Books.InStock - 2
    WHERE
        Books.BookID = Orders.BookID
        AND Orders.OrderID = 1002;
    

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