选择最大值行 [英] select maximum value row

问题描述

我只想在数据库表中选择最新的请求.
这意味着我要选择最大请求ID号和相关的行值.

我将sql查询写为

I want to select only the newest request in the database table.
that means i want to select the maximum request ID number and related row values.

I wrote sql query as

select docName,max(appID) as appID 
from Appointment 
where patID='p00000001' 
group by docName;

发生了如下错误.
在需要条件的上下文中在'')''附近指定的非布尔类型的表达式.

任何人都知道一种解决问题的方法.

An error occured as follow.
An expression of non-boolean type specified in a context where a condition is expected, near '')''.

Any one know a method to solve the problem

推荐答案

您的查询看起来还可以，但不会导致最大appid的记录集.

试试

your query looks okay but it will not result the record set of the maximum appid.

try

select *
from Appointment
where appID = (
select max(appID)
from Appointment
where patID='p00000001')

另外，希望patID列是varchar吗?

Also, hope the patID column is varchar ?

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