Question

我有两个查询从不同的表中返回单个值（并且不以任何方式通过关系加入），并且我尝试将两个查询组合在一起。输出到一行，但我得到语法错误。这就是我正在尝试的：

SELECT
    (SELECT Timestamp As StartDate 
     FROM Events 
     WHERE Description = 'Inserted') AS StartDate,
    (SELECT TOP (1) Timestamp As EndDate 
     FROM DataStore 
     ORDER BY Timestamp DESC) AS EndDate

这就是我回来的原因：

解析查询时出错。 [令牌行号= 2，令牌 line offset = 2，Token in error = SELECT]

查询1本身的回报：＆＃34; 2015-06-10 11：43：34.000＆＃34;和查询2返回：＆＃34; 2015-06-11 13：59：47.000＆＃34;

我想返回一行有两列，查询1的输出为＆＃34; StartDate＆＃34;列，以及查询2的输出为＆＃34; EndDate＆＃34;列。

Answer 1

与第二个查询不同，第一个查询可能返回2个或更多值。尝试在第一个查询中添加TOP (1)，因为我认为您只是在寻找最佳结果。

SELECT
(SELECT TOP (1) Timestamp As StartDate FROM Events WHERE Description = 'Inserted') AS StartDate,
(SELECT TOP (1) Timestamp As EndDate FROM DataStore Order by Timestamp DESC) AS EndDate

请参阅此SQL Fiddle link了解我所做的测试。

Answer 2

declare @q1 as varchar(max)
declare @q2 as varchar(max)
SELECT @q1= Timestamp FROM Events WHERE Description = 'Inserted' 
SELECT TOP (1) @q2= Timestamp FROM DataStore Order by Timestamp DESC
select @q1 as StartDate, @q2 as EndDate

Answer 3

SQL CE不支持嵌套这样的SELECT语句，因此您必须使用两个SELECT语句并使用UNION或两次调用ExecuteNonQuery。

Answer 4

试试这个：

SELECT StartDate.StartDate, EndDate.EndDate
FROM
(SELECT Timestamp As StartDate FROM Events WHERE Description = 'Inserted') AS StartDate
CROSS JOIN
(SELECT TOP (1) Timestamp As EndDate FROM DataStore Order by Timestamp DESC) AS EndDate

SQL Server CE：如何将两个查询的结果合并为一行？

4 个答案: