Question

我对下面的陈述有困难。我尝试过多种方式编写，但会相应地收到不同的错误。我希望将结果输出到单个表中，每个计数都在一个单独的（但相邻的）列中，就像这样......

 --------+--------+--------
| alias1 | alias2 | alias3 |
 --------+--------+--------
| count1 | count2 | count3 |
 --------+--------+--------

方法1：

SELECT COUNT(*) 
FROM AdventureWorks2012.HumanResources.Department AS Alias1
, (SELECT COUNT(*) 
    FROM AdventureWorks2012.HumanResources.Employee) AS Alias2
, (SELECT COUNT(*)  
    FROM AdventureWorks2012.HumanResources.EmployeeDepartmentHistory) AS Alias3

这会在Alias2（和Alias3）上返回一个错误，说明＆＃34;没有为第1列＆＃39; Alias2＆＃39;＆＃34;＆＃34;

指定列

然后我尝试按如下方式重做：

SELECT COUNT(*) 
FROM AdventureWorks2012.HumanResources.Department AS Alias1
, (SELECT COUNT(*) AS Alias2
    FROM AdventureWorks2012.HumanResources.Employee) 
, (SELECT COUNT(*) AS Alias3
    FROM AdventureWorks2012.HumanResources.EmployeeDepartmentHistory)

错误转移到＆＃39;，＆＃39;将SELECT语句与错误分开，＆＃34;＆＃39;，＆＃39;附近的语法错误。期待AS，ID或QUOTED_ID。＆＃34;

我试图做的事似乎很简单，但我是空洞的。任何帮助将不胜感激。

Answer 1

SELECT 
    (SELECT COUNT(*) FROM AdventureWorks2012.HumanResources.Department)  AS Alias1, 
    (SELECT COUNT(*) FROM AdventureWorks2012.HumanResources.Employee) AS Alias2, 
    (SELECT COUNT(*) FROM AdventureWorks2012.HumanResources.EmployeeDepartmentHistory) AS Alias3

Answer 2

获得所需结果的一种方法是将每个语句用作派生表：

SELECT * FROM 
(SELECT COUNT(*) AS Alias1 FROM AdventureWorks2012.HumanResources.Department) AS a1 , 
(SELECT COUNT(*) AS Alias2 FROM AdventureWorks2012.HumanResources.Employee) AS a2, 
(SELECT COUNT(*) AS Alias3 FROM AdventureWorks2012.HumanResources.EmployeeDepartmentHistory) AS a3

（或者您可以将这些语句用作子查询，如另一个答案中所示）

SQL Server - 使用多个表的COUNT语句很困难

2 个答案: