在一个查询中进行选择和更新 [英] Making select and update in one query
本文介绍了在一个查询中进行选择和更新的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!
问题描述
是否有一个查询,我可以一次完成两个查询?
is there a query where I can do both querys in one?
这是第一个
$q = "select c.id as campaignId,c.priceFactor,
o.cid,o.bloggerPrice,o.state as state,o.customerPrice,o.id as orderId,o.listPrice,o.basicPrice
from campaign c, orders o
where c.id={$campaignId}
and c.id = o.cid
and o.state in (8,9)";
这是第二个
foreach($orders as $order)
{
$listPrice = $order->priceFactor * $order->basicPrice;
if($order->bloggerPrice < $listPrice || $order->customerPrice < $listPrice)
{
$order->bloggerPrice = $listPrice;
$order->customerPrice = $listPrice;
}
$qUpdate = "update orders set
listPrice = {$listPrice},bloggerPrice={$order->bloggerPrice},
customerPrice ={$order->customerPrice}
where id=$order->orderId and cid={$order->cid}";
// $this->db->q($qUpdate);
}
我的问题是:仅使用纯SQL,是否可以在没有PHP代码的情况下完成以上操作?
My question is: Can I do it the above without a PHP code just pure SQL?
推荐答案
在MySQL中,您可以在UPDATE之后立即使用联接.在您的示例中,这可能类似于:
In MySQL, you can use a join right after UPDATE. In your example, this might look something like:
update Orders o
inner join Campaign c on c.id = o.cid
set
listPrice = o.priceFactor * order.basicPrice
, bloggerPrice = case
when o.bloggerPrice < o.priceFactor * order.basicPrice
then o.priceFactor * order.basicPrice
else bloggerPrice
end
, listPrice = case
when o.customerPrice < o.priceFactor * order.basicPrice
then o.priceFactor * order.basicPrice
else listPrice
end
where o.state in (8,9)
and c.id = {$campaignId}
这篇关于在一个查询中进行选择和更新的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持IT屋!
查看全文