Question

我有一个带分组的sql select命令，我想得到总行数。我如何实现这一目标？

我的sql命令：

select p.UserName, p.FirstName + ' ' + p.LastName as [FullName]
 ,count(b.billid) as [Count], sum(b.PercentRials) as [Sum] from Bills b
inner join UserProfiles p on b.PayerUserName=p.UserName
 where b.Successful=1
 group by p.UserName, p.FirstName + ' ' + p.LastName

我试过这些没有运气：

select count(*) from (select ...)

和

select count(select ...)

修改

这是我想要运行的完整的sql语句：

select count(*) from (    select p.UserName, p.FirstName + ' ' + p.LastName as [FullName]
 ,count(b.billid) as [Count], sum(b.PercentRials) as [Sum] from Bills b
inner join UserProfiles p on b.PayerUserName=p.UserName
 where b.Successful=1
 group by p.UserName, p.FirstName + ' ' + p.LastName)

我在最后一行收到此错误：

Incorrect syntax near ')'.

Answer 1

SELECT COUNT(*)
FROM 
(
select p.UserName, p.FirstName + ' ' + p.LastName as [FullName]
 ,count(b.billid) as [Count], sum(b.PercentRials) as [Sum] from Bills b
inner join UserProfiles p on b.PayerUserName=p.UserName
 where b.Successful=1
 group by p.UserName, p.FirstName + ' ' + p.LastName   --<-- Removed the extra comma here
) A  --<-- Use an Alias here

正如我所预期的那样，你错过了别名

select count(*) 
from (select ...) Q  --<-- This sub-query in From clause needs an Alias

修改

如果您只需要知道此查询返回的行，并且您正在代码中执行此查询，则只需使用@@ROWCOUNT函数即可。像......那样......

SELECT ...... --<-- Your Query SELECT @@ROWCOUNT --<-- This will return the number of rows returned -- by the previous query

Answer 2

试试这段代码：

SELECT COUNT(*)
    FROM (
           SELECT p.UserName
               ,p.FirstName + ' ' + p.LastName AS [FullName]
               ,COUNT(b.billid) AS [Count]
               ,SUM(b.PercentRials) AS [Sum]
            FROM Bills b
            INNER JOIN UserProfiles p
                ON b.PayerUserName = p.UserName
            WHERE b.Successful = 1
            GROUP BY p.UserName
               ,p.FirstName + ' ' + p.LastName
         ) a

根据您的修改。您缺少派生的表别名。

如果查看FROM子句语法，您将看到

| derived_table [AS] table_alias [（column_alias [，... n]）]

当派生表，行集或表值函数或运算符时   使用了子句（例如PIVOT或UNPIVOT），必需的table_alias at   子句的结尾是所有列的关联表名，   包括分组列，返回。

http://technet.microsoft.com/en-us/library/ms177634.aspx

Answer 3

您的子查询

后缺少别名

select count(*) from (select ...) v

您还可以尝试使用现有SQL返回总计数，而不使用子查询

select p.UserName, 
p.FirstName + ' ' + p.LastName as [FullName],
count(b.billid) as [Count], 
sum(b.PercentRials) as [Sum],
COUNT(*) over () [TotalCount] ------- total count here
from Bills b
inner join UserProfiles p on b.PayerUserName=p.UserName
where b.Successful=1
group by p.UserName, p.FirstName + ' ' + p.LastName

Answer 4

如果你有一个唯一的列名，你可以计算。例如，我假设UserName在这里是唯一的。

select count(query.UserName) from ( 
select p.UserName, p.FirstName + ' ' + p.LastName as [FullName]
 ,count(b.billid) as [Count], sum(b.PercentRials) as [Sum] from Bills b
inner join UserProfiles p on b.PayerUserName=p.UserName
 where b.Successful=1
 group by p.UserName, p.FirstName + ' ' + p.LastName) as query

Answer 5

COUNT（） - 聚合函数

SELECT SQL_CALC_FOUND_ROWS * FROM ...; SELECT FOUND_ROWS（）; //下一个查询!!!!

Sql：从（选择...）中选择count（*）

5 个答案: