Question

我需要使用下面的示例数据来计算两列。

示例数据

Project       Node
------------------
Project1      Node1
Project2      Node1
Project3      Node2

示例输出

3 Projects 2 Nodes

Answer 1

我通常不会在没有尝试提取某些努力证据的情况下发布答案，但......

cmd.CommandText = "UPDATE Accounts SET " & _
                  "credits = '" & val(credit.Text) + 10 & "'" & _
                  "WHERE username = '" & Form1.txtuname.Text & '"

Answer 2

尝试此查询

definesPresentationContext

Answer 3

试试这个

SELECT CAST(COUNT(DISTINCT Project) as varchar(50))+' Projects '
     + CAST(COUNT(DISTINCT Node) as varchar(50))+ ' Nodes'
FROM dbo.YourTable

Answer 4

select 
    count(project) as project, 
    count(distinct node) as node 
from test;

sqlfiddle

Answer 5

我不确定您为什么不想使用distinct，因为您已对其他答案发表了评论，但这将在没有distinct的情况下发挥作用。但是，它更加丑陋 - 除非您需要执行partition或其他一些不允许distinct的语法，否则通常不是一个好主意。

select max(DR_Nodes) as Nodes, max(DR_Projects) as Projects
from
(
  select *
  , dense_rank() over (order by node) as DR_Nodes
  , dense_rank() over (order by project) as DR_Projects
  from test
) a

或者，甚至更丑陋：

select * from
(select count(*) as Nodes from
    (select node
    from test
    group by node) a
) a
inner join
(select count(*) as Projects from
    (select project
    from test
    group by project) b
) b
on 1 = 1

使用SQL Server计算两列

5 个答案: