Mysql 如何将这些SQL SELECT查询组合到一个SELECT语句中

如何将这两个select语句组合到一个查询中：

SELECT SUM( incidents )  AS fires, neighborhoods AS fire_neighborhoods
FROM (
SELECT * 
FROM `fires_2009_incident_location` 
UNION ALL SELECT * 
FROM `fires_2008_incident_location`
UNION ALL SELECT * 
FROM `fires_2007_incident_location`
UNION ALL SELECT * 
FROM `fires_2006_incident_location`
) AS combo
GROUP BY fire_neighborhoods ORDER BY fires DESC



SELECT SUM( incidents )  AS adw, neighborhoods AS adw_neighborhoods
FROM (
SELECT * 
FROM `adw_2009_incident_location` 
UNION ALL SELECT * 
FROM `adw_2008_incident_location`
UNION ALL SELECT * 
FROM `adw_2007_incident_location`
UNION ALL SELECT * 
FROM `adw_2006_incident_location`
) AS combo2
GROUP BY adw_neighborhoods ORDER BY adw DESC

因此，我希望返回查询，类似于：

fire_neighborhoods  fires  adw_neighborhoods  adw
xyzNeighborhood     6      abcNeighborhood    22
jklNeighborhood     3      tuvNeighborhood    40

我只想简单地结合上面两个查询的结果。这两个查询彼此独立。一个查询的结果不会影响另一个查询的结果。我只需要一种方法将两个结果合并为一个

如果有人有任何建议，请告诉我

多谢各位

---

-Laxmidi

如果我正确理解您的需求，您可以将查询合并在一起，添加一列，让您知道它来自哪个查询：

SELECT SUM( incidents )  AS fires_or_adw, neighborhoods AS fire_or_adw_neighborhoods, 'Fires' as which_query
FROM (
SELECT * 
FROM `fires_2009_incident_location` 
UNION ALL SELECT * 
FROM `fires_2008_incident_location`
UNION ALL SELECT * 
FROM `fires_2007_incident_location`
UNION ALL SELECT * 
FROM `fires_2006_incident_location`
) AS combo
GROUP BY fire_neighborhoods ORDER BY fires DESC

UNION

SELECT SUM( incidents )  AS fires_or_adw, neighborhoods AS fire_or_adw_neighborhoods, 'ADW' as which_query
FROM (
SELECT * 
FROM `adw_2009_incident_location` 
UNION ALL SELECT * 
FROM `adw_2008_incident_location`
UNION ALL SELECT * 
FROM `adw_2007_incident_location`
UNION ALL SELECT * 
FROM `adw_2006_incident_location`
) AS combo2
GROUP BY adw_neighborhoods ORDER BY adw DESC

---

假设您的行数是原来的两倍，并且一半的数据将为空，但是像您的示例中那样将结果“砰砰”地放在一起是不常见的。

您给出的示例表明您希望水平组合查询，但后来您声明它们是完全独立的。这些语句相互冲突，因为当记录彼此相关时，通常会水平组合数据。下面是我横向组合它们的想法，但我也记下了我纵向组合它们的想法

这取决于你想如何把它们联系起来。如果您是基于邻居进行查询，则可以在fire_Neighbories=adw_Neighbories上的两个较大查询之间进行连接，例如：

SELECT fire_neighborhoods, fires, adw
FROM (

SELECT SUM( incidents )  AS fires, neighborhoods AS fire_neighborhoods
FROM (
SELECT * 
FROM `fires_2009_incident_location` 
UNION ALL SELECT * 
FROM `fires_2008_incident_location`
UNION ALL SELECT * 
FROM `fires_2007_incident_location`
UNION ALL SELECT * 
FROM `fires_2006_incident_location`
) AS combo
GROUP BY fire_neighborhoods ORDER BY fires DESC

) AS fires
    INNER JOIN (  

SELECT SUM( incidents )  AS adw, neighborhoods AS adw_neighborhoods
FROM (
SELECT * 
FROM `adw_2009_incident_location` 
UNION ALL SELECT * 
FROM `adw_2008_incident_location`
UNION ALL SELECT * 
FROM `adw_2007_incident_location`
UNION ALL SELECT * 
FROM `adw_2006_incident_location`
) AS combo2
GROUP BY adw_neighborhoods ORDER BY adw DESC

) AS adw
    ON fires.fire_neighborhoods = adw.adw_neighborhoods

这只是一个例子。您可能需要一个不同的连接或其他东西来让它为您工作

---

现在，您声明这两个查询是独立的，并且不会相互影响。如果它们确实没有共同点，您应该在每个查询中添加一列，指明它来自哪个查询（例如，对于fire查询，添加一个常量值为1的列；对于adw查询，添加一个常量值为2的列）。然后，将两个大型查询合并在一起。这将以垂直方式而不是水平方式将它们组合起来。

其他人给出的关于使用鉴别器列的答案与您的要求类似，但为了以防万一，可以将虚拟占位符列添加到联合中，如下所示：

SELECT 
    SUM( incidents )  AS fires, 
    neighborhoods AS fire_neighborhoods,
    0 as adw,
    '' as adw_neighbourhoods
FROM ( 
    SELECT *  
    FROM `fires_2009_incident_location`  
    UNION ALL SELECT *  
    FROM `fires_2008_incident_location` 
    UNION ALL SELECT *  
    FROM `fires_2007_incident_location` 
    UNION ALL SELECT *  
    FROM `fires_2006_incident_location` 
) AS combo 
GROUP BY fire_neighborhoods ORDER BY fires DESC 

UNION 

SELECT 
    0 as fires,
   '' as fire_neighbourhoods,
    SUM( incidents )  AS adw, 
    neighborhoods AS adw_neighborhoods 
FROM ( 
    SELECT *  
    FROM `adw_2009_incident_location`  
    UNION ALL SELECT *  
    FROM `adw_2008_incident_location` 
    UNION ALL SELECT *  
    FROM `adw_2007_incident_location` 
    UNION ALL SELECT *  
    FROM `adw_2006_incident_location` 
) AS combo2 
GROUP BY adw_neighborhoods ORDER BY adw DESC

---

并排显示两个不相关的查询通常是报表软件的工作，而不是SQL引擎的工作。这里的问题是，您要求查询工具执行它不适合执行的操作：显示格式

关系（从根本上说，选择的结果应该是什么）是一种对世界状态做出断言的数据结构。每行定义一系列（理想情况下）为真的命题

---

在您的问题中，这些行包含任意的事实陈述，这些事实彼此之间没有关联，也无法陈述任何命题。

感谢您帮助我们解决这个问题。向David Hall、Aaron、Jeffrey Whitledge&NYSystems分析师大声呼喊。我选择了虚拟列选项：

SELECT SUM( incidents ) , neighborhoods,  'adw' as offense 
FROM (
SELECT * 
FROM `adw_2009_incident_location` 
UNION ALL SELECT * 
FROM `adw_2008_incident_location`
UNION ALL SELECT * 
FROM `adw_2007_incident_location`
UNION ALL SELECT * 
FROM `adw_2006_incident_location`
) AS combo 
GROUP BY neighborhoods  
UNION ALL
SELECT SUM( incidents ), neighborhoods,  'fire' as offense 
FROM (
SELECT * 
FROM `fire_2009_incident_location` 
UNION ALL SELECT * 
FROM `fire_2008_incident_location`
UNION ALL SELECT * 
FROM `fire_2007_incident_location`
UNION ALL SELECT * 
FROM `fire_2006_incident_location`
) AS combo2
GROUP BY neighborhoods 

---

我一定错过了什么。为什么不能将这两个查询合并在一起？可以发布表的结构吗？为什么人们投票支持这个问题？这个问题真的有用吗？这对我来说似乎相当学术和多余。@Jim G:责怪选民徽章：为什么模式每年映射一个表？这些是视图吗？嗨，Aaron，我想我不需要水平返回数据。我可以添加一个列，指示是火灾还是adw，然后让其他列显示邻居和事件-Laxmidhi Aaron，我忘了在上一封邮件中说“谢谢”。对不起-杰弗里，你说得对。水平返回数据是没有意义的。谢谢-嗨，大卫，谢谢你的留言。我试过你的建议，但不幸的是，我没能把它付诸实施。可以在mySQL中添加虚拟列吗-Laxmidi@Laxmidi-运行该语法时是否看到错误？我不确定mySQL，尽管我希望它能工作。Tour问题被某人重新标记为tsql，这是microsoft sql实现，我现在将重新标记它。您好，NYSystemsAnalyst，感谢您建议添加带有常量的列。我最终可能会那样做-拉西米地