将多个 Sql 查询合并为一个答案

【问题标题】：Combine Multiple Sql Queries into one将多个 Sql 查询合并为一个
【发布时间】：2014-07-01 05:49:11
【问题描述】：

我在名为“latest”的 sql 表中有一个名为“status”的列，其中包含五个不同的值 new、deployed、resolved、assigned 和 closed，如下所示

 Status
--------------
  NEW
  NEW
  DEPLOYED
  NEW
  RESOLVED
  ASSIGNED
  ASSIGNED
  RESOLVED
  ASSIGNED
  NEW
  NEW
  RESOLVED
  CLOSED
  ASSIGNED

我想编写一个查询，我可以在其中计算每个单词在“状态”列中出现的次数。目前我在这样的 5 个不同查询中使用 count 函数。

 1)select count(status) from latest where status="NEW";
 2)select count(status) from latest where status="DEPLOYED";
 3)select count(status) from latest where status="RESOLVED";
 4)select count(status) from latest where status="ASSIGNED";
 5)select count(status) from latest where status="CLOSED";

有没有一种方法可以将所有这些查询组合成一个查询，而无需使用连接或联合来获得 5 个不同的计数值？？

【问题讨论】：

重复stackoverflow.com/questions/9650099/…
@Aniruddh：查看我的答案。希望对您有所帮助！

标签： sql select oracle11g count subquery

【解决方案1】：

问题 1：

SELECT STATUS, COUNT(1) FROM LATEST
GROUP BY STATUS
ORDER BY STATUS;

您的输出将是：

STATUS         COUNT
ASSIGNED       4
CLOSED         1
DEPLOYED       1
NEW            5
RESOLVED       3

要获得包含 5 列的单行输出，您可以使用： 问题 2：

SELECT COUNT(CASE WHEN STATUS='ASSIGNED' THEN 1 END)  ASSIGNED_COUNT,
COUNT(CASE WHEN STATUS='CLOSED' THEN 1 END)  CLOSED_COUNT,
COUNT(CASE WHEN STATUS='DEPLOYED' THEN 1 END)  DEPLOYED_COUNT,
COUNT(CASE WHEN STATUS='NEW' THEN 1 END)  NEW_COUNT,
COUNT(CASE WHEN STATUS='RESOLVED' THEN 1 END)  RESOLVED_COUNT
FROM LATEST

您的输出将是：

ASSIGNED_COUNT   | CLOSED_COUNT | DEPLOYED_COUNT | NEW_COUNT | RESOLVED_COUNT
4                |  1           | 1              | 5         | 3

解释：

查询 1 可用于可以有任意数量的动态状态的情况。例如，即使存在名为 DEFERRED 的状态，它也会自动包含在内，而不会更改查询。但是，如果说没有状态为“NEW”的记录，则不会返回任何数据。
查询 2 可用于返回单行中的所有数据。如果要包含新状态，则必须修改查询。如果没有状态记录，则返回 0。 仪表板的理想选择。

【讨论】：

【解决方案2】：

试试这个很酷的

  Select *
  from
  (
  Select Status,COUNT(*) 'Count'
  from LATEST
  group by Status with rollup
  ) t
  where t.Count is not null

【讨论】：

【解决方案3】：

试试这个：

SELECT l.status, COUNT(1) 
FROM latest l
GROUP BY l.status;

或

SELECT SUM(l.status = 'NEW') AS NEW_STATUS,  
       SUM(l.status = 'DEPLOYED') AS DEPLOYED_STATUS, 
       SUM(l.status = 'RESOLVED') AS RESOLVED_STATUS, 
       SUM(l.status = 'ASSIGNED') AS ASSIGNED_STATUS, 
       SUM(l.status = 'CLOSED') AS CLOSED_STATUS
FROM latest l;

更新

使用SELECT...INTO 语句来实现这一点，检查下面的查询

SELECT SUM(l.status = 'NEW') AS NEW_STATUS,  
       SUM(l.status = 'DEPLOYED') AS DEPLOYED_STATUS, 
       SUM(l.status = 'RESOLVED') AS RESOLVED_STATUS, 
       SUM(l.status = 'ASSIGNED') AS ASSIGNED_STATUS, 
       SUM(l.status = 'CLOSED') AS CLOSED_STATUS 
       INTO NEW_STATUS, DEPLOYED_STATUS, RESOLVED_STATUS, 
            ASSIGNED_STATUS, CLOSED_STATUS
FROM latest l;

【讨论】：

通过使用上面的查询，我会得到 5 个不同的计数值吗？我可以将它们存储在 5 个不同的变量中吗？？

【解决方案4】：

试试这个...

1.>

Select Count() as Count,Status from latest where (status='NEW' or status='DEPLOYED' or status='RESOLVED' or status='ASSIGNED' or status='CLOSED ') 按状态分组；*

或

2.> select count(status) from latest where (status='NEW' Or status='DEPLOYED' or status='RESOLVED' or status='ASSIGNED' Or status='CLOSED')；

【讨论】：