UPDATE invoices
    SET
    payment_total = invoice_total * 0.5,
    payment_date = due_date
    WHERE client_id = 3

    UPDATE invoices
    SET
    payment_total = invoice_total * 0.5,
    payment_date = due_date
    WHERE client_id IN (3, 4)

    给customers表内数据增加五十分
    USE sql_store;

    UPDATE customers
    SET points = points + 50
    WHERE birth_date < ‘1990-01-01’