Question

我遇到了将多个查询合并到一个输出中的麻烦。我是SQL的初学者，想知道是否有人可以提供一些关于如何完成这项工作的反馈。

这是我的代码：

SELECT [status], [queryno_i] as 'Query ID', [assigned_to_group] as 'Assigned To Group', [issued_date] as 'Issuing Date',
CASE
    WHEN [status] = 3 THEN [mutation]
    ELSE NULL
END AS 'Closing Date'
 FROM tablename.[tech_query] WITH (NOLOCK)


SELECT
CASE
    WHEN [status] = 3 THEN 'CLOSED'
    ELSE 'OPEN'
END AS [State]
 FROM tablename.[tech_query] WITH (NOLOCK)


SELECT
CASE
    WHEN [status] = 3 THEN [mutation_int]-[issued_date_INT]
    ELSE NULL
END AS [TAT]
 FROM tablename.[tech_query] WITH (NOLOCK)

Answer 1

如果你想把所有人都放在一起

SELECT [status], 
      [queryno_i] as 'Query ID', 
      [assigned_to_group] as 'Assigned To Group', 
      [issued_date] as 'Issuing Date',
      CASE WHEN [status] = 3 THEN [mutation] ELSE NULL END AS 'Closing Date',
      CASE WHEN [status] = 3 THEN 'CLOSED' ELSE 'OPEN' END AS [State],
      CASE WHEN [status] = 3 THEN [mutation_int]-[issued_date_INT] ELSE NULL 
            END AS [TAT]
 FROM tablename.[tech_query] WITH (NOLOCK)

Answer 2

使用SQL，一切都必须是一个结果集。为了返回所有这些查询的结果，它们都必须具有相同的列（和数据类型）。

您能将所有内容组合成一个选择查询吗？

SELECT 
    [status]
    , [queryno_i] as 'Query ID'
    , [assigned_to_group] as 'Assigned To Group'
    , [issued_date] as 'Issuing Date'
    , CASE
        WHEN [status] = 3 THEN [mutation]
        ELSE NULL
        END AS 'Closing Date'
    , NULL AS State
    , NULL AS Tat
    , 1 AS QueryNumber
FROM 
    [tech_query] 

UNION ALL

SELECT NULL,NULL,NULL,NULL,NULL,
    CASE
        WHEN [status] = 3 THEN 'CLOSED'
        ELSE 'OPEN'
    END AS [State]
    , NULL
    , 2 AS QueryNumber
FROM 
    [tech_query] 

UNION ALL

SELECT NULL,NULL,NULL,NULL,NULL, NULL
CASE
    WHEN [status] = 3 THEN [mutation_int]-[issued_date_INT]
    ELSE NULL
END AS [TAT]
, 3 AS QueryNumber
FROM 
    [tech_query]

Answer 3

你在找这样的东西吗？

SELECT [status], [queryno_i] as 'Query ID', 
   [assigned_to_group] as 'Assigned To Group', [issued_date] as 'Issuing Date',
CASE
   WHEN [status] = 3 THEN [mutation]
   ELSE NULL
END AS 'Closing Date',

CASE
   WHEN [status] = 3 THEN 'CLOSED'
   ELSE 'OPEN'
END AS [State],

CASE
   WHEN [status] = 3 THEN [mutation_int]-[issued_date_INT]
   ELSE NULL
END AS [TAT]


FROM tablename.[tech_query] WITH (NOLOCK)

Answer 4

案例陈述是内联的

SELECT 
  [status], 
  [queryno_i] as 'Query ID', 
  [assigned_to_group] as 'Assigned To Group', 
  [issued_date] as 'Issuing Date',
  CASE
      WHEN [status] = 3 THEN [mutation]
      ELSE NULL
  END AS 'Closing Date',
  CASE
    WHEN [status] = 3 THEN 'CLOSED'
    ELSE 'OPEN'
  END AS [State],
  SELECT
  CASE
      WHEN [status] = 3 THEN [mutation_int]-[issued_date_INT]
      ELSE NULL
  END AS [TAT]
  FROM tablename.[tech_query] WITH (NOLOCK)

为什么nolock？

Answer 5

您可以使用UNION子句

http://www.w3schools.com/sql/sql_union.asp

SELECT 1 
  UNION ALL
SELECT 2
  UNION ALL
SELECT 3

但是，通过查看3个语句，所有3个选项都来自同一个表，因此您可以组合并使用CASE语句来获得结果，而无需使用Union。

SQL如何将多个SQL查询组合成一个输出

5 个答案: