SELECT
price * number #列1乘以列2
AS usdt #別名
FROM
order_btccoin #表名
WHERE
buy_uid = 13307325 255.0046567135846 #條件
加就加,乘就乘,減就減
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如果要統計查出的值的話可以這樣
select sum(usdt)from(select price*number AS usdt from order_btccoin WHERE buy_uid=13307325)usdt
