Question

如何将几个结果集合并为一个。假设我有这五个sql选择，它们都采用相同的“简单”输入（10）：

SELECT agentid, latitude, longitude, availability, updated
FROM table1
WHERE agentid=10

SELECT email, name, phone, company
FROM table2
WHERE userid=10

SELECT COUNT(*) AS pt1num
FROM table3
WHERE agentid=10 AND propertytype<6

SELECT COUNT(*) AS pt2num
FROM table3
WHERE agentid=10 AND propertytype>6 AND propertytype<9

SELECT COUNT(*) AS pt3num
FROM table3
WHERE agentid=10 AND propertytype>8

如何UNION或JOIN或子查询，以便我获得包含所有列的行; agentid，纬度，经度，可用性，更新，电子邮件，名称，电话，公司，pt1num，pt2num，pt3num？

Answer 1

一种方法是使用Common table expressions，然后交叉加入

    with cte1 as ( 
    SELECT agentid, latitude, longitude, availability, updated
    FROM table1
    WHERE agentid=10)
    , cte2 as (

    SELECT email, name, phone, company
    FROM table2
    WHERE userid=10)

    , cte3 as (
    SELECT COUNT(*) AS pt1num
    FROM table3
    WHERE agentid=10 AND propertytype<6)

    , cte4 as (SELECT COUNT(*) AS pt2num
    FROM table3
    WHERE agentid=10 AND propertytype>6 AND propertytype<9)

    ,  cte5 as (
    SELECT COUNT(*) AS pt3num
    FROM table3
    WHERE agentid=10 AND propertytype>8)


SELECT [youfieldlist] 
FROM 
  cte1, cte2, cte3, cte4, cte5

另一种方法是使用内联视图

Select [your field list]
FROM (
SELECT agentid, latitude, longitude, availability, updated
FROM table1
WHERE agentid=10 ) t1,
(
SELECT email, name, phone, company
FROM table2
WHERE userid=10) t2, 
(
SELECT COUNT(*) AS pt1num
FROM table3
WHERE agentid=10 AND propertytype<6) t3,
(
SELECT COUNT(*) AS pt2num
FROM table3
WHERE agentid=10 AND propertytype>6 AND propertytype<9) t4,
(
SELECT COUNT(*) AS pt3num
FROM table3
WHERE agentid=10 AND propertytype>8) t5

如果您知道每个选择只返回一行

，这些只是非常合理

您还可以使用局部变量进行每次选择

DECLARE @agentid int, @latitude int , ... 
SELECT   @agentid = agentid,  @latitude = latitude, ...
        FROM table1
        WHERE agentid=10

DECLARE @pt1num int
 SELECT @pt1num  = COUNT(*)  
    FROM table3
    WHERE agentid=10 AND propertytype<6

然后选择它们

SELECT  @agentid agentid,  @latitude latitude, ... @pt1num...

从具有相同输入的多个表中进行SELECT（SQL SERVER 2005）

1 个答案: