在SQL语句中除法。 [英] Division in a SQL statement.
问题描述
好吧,我的问题:
我有一个表itemconfig,其中有很多数据存储在我们的仓库中。我需要选择特殊的组
项目,以便进行一些与工作相关的测试。到目前为止,当我滚动数据库时,我脑子里一直在做数学运算,但是肯定有一种更简单的方法。
I have a table itemconfig where there is lots of data concerning items stored in our warehouses. I need to select a special group
of items so I can do some job related testing. So far I've been doing the math in my head as I scroll through the database but there must be an easier way.
在itemconfig中,我想专门查看case_qty和pal_qty以及itm_num列。我想做的是选择所有itm_num,其中 pal_qty / case_qty
大于 500
。这将立即给我所有与测试相关的 itm_num
。遗憾的是,我不知道如何执行此操作,甚至可能不熟悉。
Within itemconfig I want to specifically look at columns case_qty and pal_qty and itm_num. What I would like to do is select all itm_num where pal_qty / case_qty
is greater than say 500
. This would give me all itm_num
instantly that are relevant to my tests. Sadly I'm not familiar with how to do this or if it's even possible.
谢谢。
推荐答案
在大多数SQL方言中都实现了除法:使用 /
,例如
Division is implemented in most SQL dialects: use /
, like this:
select * from table
where pal_qty / case_qty > 500
假设 case_qty
为非负数,您可以通过将两边都乘以 case_qty
pal_qty 上的索引,如果有*) >:
Assuming case_qty
is non-negative, you can shield yourself from division by zero (and use indexes on pal_qty
, if any*) by multiplying both sides by case_qty
:
select * from table
where pal_qty > 500 * case_qty
*谢谢文森特·萨瓦德对此观察。
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