是否可以从我的MySQL数据库中的一个表中的一行中获取值并插入到同一数据库中的另一个表中?

当然。在我通常的做法中,我只是将价格作为插入的一部分发送,但是如果您确实需要从产品表中提取价格,那么您可以使用子选项执行此操作,例如:

INSERT INTO `purchase`
SET `product_id` = $whatever,
`price` = (
    SELECT `price`
    FROM `product`
    WHERE `id` = $whatever
)

INSERT INTO purchases (
    price
    ,productid
    ,add your other columns here
)
SELECT price
    ,id
    ,add your other columns here
FROM products
WHERE add your selection criteria here

可能的:

insert into purchases(purchase_id, product_id, price) 
select 88, product_id, current_price from product 
where product_id = 'KEYB'

要包括当前折扣:

insert into purchases(purchase_id, product_id, price, discount) 
select 88, product_id, current_price, current_discount from product 
where product_id = 'KEYB'