Question

我正在尝试将行数据转换为列。将从不同的表中提取数据。我尝试使用PIVOT，但我没有太大成功。

让我们将column#1视为每个表中的主键。

CREATE TABLE Table_pivot_01
    ([SSN ID] int, [Citizen_name] varchar(5), [Company] varchar(4))
;

INSERT INTO Table_pivot_01
    ([SSN ID], [Citizen_name], [Company])
VALUES
    (12345, 'John', 'XYZ'),
    (12346, 'Tom', 'ABC'),
    (12347, 'Jerry', 'QWER'),
    (12348, 'Joe', 'PQR'),
    (12349, 'Josh', NULL)
;

CREATE TABLE Table_pivot_02
    ([Serial] int, [SSN_ID] int, [Family_details] varchar(9), [Family_members_name] varchar(10))
;

INSERT INTO Table_pivot_02
    ([Serial], [SSN_ID], [Family_details], [Family_members_name])
VALUES
    (1010, 12345, 'Spouse', 'Mari'),
    (1011, 12345, 'Child - 1', 'John Jr. 1'),
    (1012, 12345, 'Child - 2', 'John Jr. 2'),
    (1013, 12346, 'Spouse', 'Ken'),
    (1014, 12347, 'Spouse', 'Suzen'),
    (1015, 12347, 'Child - 1', 'Jerry Jr.1'),
    (1016, 12347, 'Child - 2', 'Jerry Jr.2'),
    (1017, 12347, 'Child - 3', 'Jerry Jr.3'),
    (1018, 12348, 'Child - 1', 'Joe Jr.1'),
    (1019, 12348, 'Child - 2', 'Joe Jr.2'),
    (1020, 12349, 'Spouse', 'Zoe'),
    (1021, 12349, 'Child - 1', 'Josh Jr.1'),
    (1022, 12349, 'Child - 2', 'Josh Jr.2')
;



CREATE TABLE Table_pivot_03
    ([Row] int, [SSN_ID] int, [Address_type] varchar(8), [Address] varchar(22), [PhoneNumber_type] varchar(6), [PhoneNumber] varchar(18))
;

INSERT INTO Table_pivot_03
    ([Row], [SSN_ID], [Address_type], [Address], [PhoneNumber_type], [PhoneNumber])
VALUES
    (121, 12345, 'Present', 'Address_John_Present', 'Home', 'John_Home_phone'),
    (122, 12345, 'Office', 'Address_John_Office', 'Office', 'John_Office_phone'),
    (123, 12345, 'Perement', 'Address_John_Perement', 'Fax', 'John_FAX_phone'),
    (124, 12346, 'Present', 'Address_Tom_Present', 'Home', 'Tom_Home_phone'),
    (125, 12346, 'Office', 'Address_Tom_Office', 'Office', 'Tom_Office_phone'),
    (126, 12347, 'Office', 'Address_Jerry_Office', 'Home', 'Jerry_Home_phone'),
    (127, 12347, 'Perement', 'Address_Jerry_Perement', 'Office', 'Jerry_Office_phone'),
    (128, 12348, 'Present', 'Address_Joe_Present', 'Home', 'Joe_Home_phone'),
    (129, 12348, 'Office', 'Address_Joe_Office', 'Office','Joe_Office_phone'),
    (130, 12348, 'Perement' , 'Address_Josh_Perement','','' ),
     (131, 12349, 'Present','Address_Josh_Present','Home','Josh_Home_phone'),
     (132, 12349, 'Perement', 'Address_Josh_Perement' , 'Fax' ,'Josh_FAX_phone');

表架构：http://rextester.com/MSXK16689

预期输出是：

Output

如何以有效的方式构建结果？

Answer 1

MySQL版本

您已声明已尝试使用PIVOT，但MySQL没有PIVOT功能。在MySQL中，您需要使用聚合函数以及类似CASE...WHEN之类的条件逻辑语句。您还需要几个表和几个不同的列，这会使这一点变得复杂。您似乎还需要创建未知数量的新列，这会增加另一层复杂性。

如果您知道要在最终结果中显示的所有列，那么您可以轻松地键入此查询的版本，如下所示：

select 
    p1.`SSN_ID`,
    p1.Citizen_name,
    p1.Company,
    max(case when p2.Family_details = 'Spouse' then Family_members_name end) Spouse,
    max(case when p2.Family_details = 'Child - 1' then Family_members_name end) Child1,
    max(case when p2.Family_details = 'Child - 2' then Family_members_name end) Child2,
    max(case when p2.Family_details = 'Child - 3' then Family_members_name end) Child3,
    max(case when p2.Family_details = 'Child - 4' then Family_members_name end) Child4,
    max(case when p3.Address_type = 'Present' then p3.Address end) PresentAddress,
    max(case when p3.Address_type = 'Office' then p3.Address end) OfficeAddress,
    max(case when p3.Address_type = 'Perement' then p3.Address end) PermAddress,
    max(case when p3.PhoneNumber_type = 'Home' then p3.PhoneNumber end) HomePhone,
    max(case when p3.PhoneNumber_type = 'Office' then p3.PhoneNumber end) OfficePhone,
    max(case when p3.PhoneNumber_type = 'Fax' then p3.PhoneNumber end) FaxPhone
from Table_pivot_01 p1
left join Table_pivot_02 p2
    on p1.`SSN_ID` = p2.`SSN_ID`
left join Table_pivot_03 p3
    on p1.`SSN_ID` = p3.`SSN_ID`
group by p1.`SSN_ID`,
    p1.Citizen_name,
    p1.Company;

基本上，您在max(case...语句中创建一个新列，它将显示该值。如前所述，如果您想要作为列的未知值，这会变得更复杂一些。在MySQL中，您需要使用Prepared Statement，以便可以使用动态SQL。您的代码看起来有点像这样：

SET @sql = NULL;   
SET @sql1 = NULL;
SET @sql2 = NULL;
SET @sql3 = NULL;
SELECT
  GROUP_CONCAT(DISTINCT
    CONCAT(
      ' max(case when p2.Family_details = ''',
      Family_details,
      ''' then Family_members_name end) AS `',
      Family_details, '`'
    )
  ) INTO @sql1
FROM  Table_pivot_02;

SELECT
  GROUP_CONCAT(DISTINCT
    CONCAT(
      ' max(case when p3.Address_type = ''',
      Address_type,
      ''' then Address end) AS `',
      Address_type, '`'
    )
  ) INTO @sql2
FROM  Table_pivot_03;

SELECT
  GROUP_CONCAT(DISTINCT
    CONCAT(
      ' max(case when p3.PhoneNumber_type = ''',
      PhoneNumber_type,
      ''' then PhoneNumber end) AS `',
      PhoneNumber_type, '`'
    )
  ) INTO @sql3
FROM  Table_pivot_03
where PhoneNumber_type <> '';

SET @sql = CONCAT('SELECT p1.`SSN_ID`,
                        p1.Citizen_name,
                        p1.Company, ', @sql1, ',', @sql2, ',', @sql3, ' 
                    from Table_pivot_01 p1
                    left join Table_pivot_02 p2
                        on p1.`SSN_ID` = p2.`SSN_ID`
                    left join Table_pivot_03 p3
                        on p1.`SSN_ID` = p3.`SSN_ID`
                    group by p1.`SSN_ID`,
                        p1.Citizen_name,
                        p1.Company');


PREPARE stmt FROM @sql;
EXECUTE stmt;
DEALLOCATE PREPARE stmt;

在此，您将创建一个max(case...语句的长字符串，这些语句将连接在一起，然后由数据库引擎执行。可能有更简单的方法来获得您想要的结果，但这确实有效。我在rextester上创建了一个演示来显示代码。这两个都产生了结果：

+-------+--------+--------------+---------+--------+------------+------------+------------+----------------------+----------------------+------------------------+------------------+--------------------+----------------+
|  Row  | SSN_ID | Citizen_name | Company | Spouse | Child - 1  | Child - 2  | Child - 3  |       Present        |        Office        |        Perement        |       Home       |       Office       |      Fax       |
+-------+--------+--------------+---------+--------+------------+------------+------------+----------------------+----------------------+------------------------+------------------+--------------------+----------------+
|     1 |  12345 | John         | XYZ     | Mari   | John Jr. 1 | John Jr. 2 | NULL       | Address_John_Present | Address_John_Office  | Address_John_Perement  | John_Home_phone  | John_Office_phone  | John_FAX_phone |
|     2 |  12346 | Tom          | ABC     | Ken    | NULL       | NULL       | NULL       | Address_Tom_Present  | Address_Tom_Office   | NULL                   | Tom_Home_phone   | Tom_Office_phone   | NULL           |
|     3 |  12347 | Jerry        | QWER    | Suzen  | Jerry Jr.1 | Jerry Jr.2 | Jerry Jr.3 | NULL                 | Address_Jerry_Office | Address_Jerry_Perement | Jerry_Home_phone | Jerry_Office_phone | NULL           |
|     4 |  12348 | Joe          | PQR     | NULL   | Joe Jr.1   | Joe Jr.2   | NULL       | Address_Joe_Present  | Address_Joe_Office   | Address_Josh_Perement  | Joe_Home_phone   | Joe_Office_phone   | NULL           |
|     5 |  12349 | Josh         | NULL    | Zoe    | Josh Jr.1  | Josh Jr.2  | NULL       | Address_Josh_Present | NULL                 | Address_Josh_Perement  | Josh_Home_phone  | NULL               | Josh_FAX_phone |
+-------+--------+--------------+---------+--------+------------+------------+------------+----------------------+----------------------+------------------------+------------------+--------------------+----------------+

根据您的评论，每个人可能有多个电话号码类型，您需要创建row number for each group of phone types。不幸的是，MySQL没有窗口函数，所以你需要使用用户定义的变量来获得最终结果。当您查询PhoneNumber_type时，您需要使用以下内容：

select *
from 
(
   select SSN_ID, PhoneNumber_type, PhoneNumber,
      @num:= case when @group = SSN_ID and @type = PhoneNumber_type then @num +1 else if(@group := SSN_ID, 1, 1) end rn,
      @group:= SSN_ID,
      @type:=PhoneNumber_type
  from Table_pivot_03 t
  CROSS JOIN (select @num:=0, @group:=null, @type:=null) c
  where t.PhoneNumber_type <> ''
  order by SSN_ID, PhoneNumber_type
) as x;

这会为每个用户和电话类型创建一个行号值。然后，您将其集成到动态SQL代码中：

SET @sql = NULL;   
SET @sql1 = NULL;
SET @sql2 = NULL;
SET @sql3 = NULL;
SELECT
  GROUP_CONCAT(DISTINCT
    CONCAT(
      ' max(case when p2.Family_details = ''',
      Family_details,
      ''' then Family_members_name end) AS `',
      Family_details, '`'
    )
  ) INTO @sql1
FROM  Table_pivot_02;

SELECT
  GROUP_CONCAT(DISTINCT
    CONCAT(
      ' max(case when p3.Address_type = ''',
      Address_type,
      ''' then Address end) AS `',
      Address_type, '`'
    )
  ) INTO @sql2
FROM  Table_pivot_03;

SELECT
  GROUP_CONCAT(DISTINCT
    CONCAT(
      ' max(case when p.PhoneNumber_type = ''',
      PhoneNumber_type,
      ''' and rn = ', rn, ' then p.PhoneNumber end) AS `',
      PhoneNumber_type, rn, '`'
    )
  ) INTO @sql3
FROM 
(
   select SSN_ID, PhoneNumber_type, PhoneNumber,
      @num:= case when @group = SSN_ID and @type = PhoneNumber_type then @num +1 else if(@group := SSN_ID, 1, 1) end rn,
      @group:= SSN_ID,
      @type:=PhoneNumber_type
  from Table_pivot_03 t
  CROSS JOIN (select @num:=0, @group:=null, @type:=null) c
  where t.PhoneNumber_type <> ''
  order by SSN_ID, PhoneNumber_type
) as x;


SET @sql = CONCAT('SELECT p1.`SSN_ID`,
                        p1.Citizen_name,
                        p1.Company, ', @sql1, ',', @sql2, ',', @sql3, ' 
                    from Table_pivot_01 p1
                    left join Table_pivot_02 p2
                        on p1.`SSN_ID` = p2.`SSN_ID`
                    left join Table_pivot_03 p3
                      on p1.SSN_ID = p3.SSN_Id
                    left join
                    (
                       select SSN_ID, PhoneNumber_type, PhoneNumber,
                          @num:= case when @group = SSN_ID and @type = PhoneNumber_type then @num +1 else if(@group := SSN_ID, 1, 1) end rn,
                          @group:= SSN_ID,
                          @type:=PhoneNumber_type
                      from Table_pivot_03 t
                      CROSS JOIN (select @num:=0, @group:=null, @type:=null) c
                      where t.PhoneNumber_type <> ''''
                      order by SSN_ID, PhoneNumber_type
                    ) as p
                       on p1.SSN_ID = p.SSN_Id
                    group by p1.`SSN_ID`,
                        p1.Citizen_name,
                        p1.Company');

#select @sql;                        

PREPARE stmt FROM @sql;
EXECUTE stmt;
DEALLOCATE PREPARE stmt;

查看另一个demo。

SQL Server版本

既然你现在说你需要一个SQL Server版本就是那个版本。 SQL Server有一些功能可以使这一过程变得更加容易，包括PIVOT函数，UNPIVOT函数和row_number等窗口函数。这是一个静态版本的查询，只有几列旋转：

select SSN_ID,
    Citizen_name,
    Company,
    Spouse, [Child - 1], [Child - 2], [Child - 3], [Child - 4]
from
(
    select SSN_ID,
        Citizen_name,
        Company, 
        col, 
        value
    from
    (
        select 
            p1.SSN_ID,
            p1.Citizen_name,
            p1.Company,
            p2.Family_details,
            p2.Family_members_name,
            p3.Address_type,
            p3.Address,
            PhoneNumber_type = p.PhoneNumber_type + cast(p.rn as varchar(10)),
            p.PhoneNumber
        from Table_pivot_01 p1
        left join Table_pivot_02 p2
            on p1.SSN_ID = p2.SSN_ID
        left join Table_pivot_03 p3
            on p1.SSN_ID = p3.SSN_ID
        left join
        (
            select SSN_ID, PhoneNumber_type, PhoneNumber,
                rn = row_number() over(partition by SSN_ID, PhoneNumber_type order by SSN_ID, PhoneNumber_type)
            from Table_pivot_03
            where PhoneNumber_type <> ''
        ) p
            on p1.SSN_ID = p.SSN_ID
    ) d
    cross apply 
    (
        select 'Family_details', Family_details, Family_members_name union all
        select 'Address_type', Address_type, Address union all
        select 'PhoneNumber_type', PhoneNumber_type, PhoneNumber
    ) c(orig, col, value)
) src
pivot
(
    max(value)
    for col in (Spouse, [Child - 1], [Child - 2], [Child - 3], [Child - 4])
) piv

然后，如果你需要动态的sql版本，代码就像：

DECLARE @cols AS NVARCHAR(MAX),
    @query  AS NVARCHAR(MAX)

select @cols = STUFF((SELECT ',' + QUOTENAME(Col) 
                    from
                    (
                        select col, ord
                        from
                        (
                            select 
                                p1.SSN_ID,
                                p1.Citizen_name,
                                p1.Company,
                                p2.Family_details,
                                p2.Family_members_name,
                                p3.Address_type,
                                p3.Address,
                                PhoneNumber_type = p.PhoneNumber_type + cast(p.rn as varchar(10)),
                                p.PhoneNumber
                            from Table_pivot_01 p1
                            left join Table_pivot_02 p2
                                on p1.SSN_ID = p2.SSN_ID
                            left join Table_pivot_03 p3
                                on p1.SSN_ID = p3.SSN_ID
                            left join
                            (
                                select SSN_ID, PhoneNumber_type, PhoneNumber,
                                    rn = row_number() over(partition by SSN_ID, PhoneNumber_type order by SSN_ID, PhoneNumber_type)
                                from Table_pivot_03
                                where PhoneNumber_type <> ''
                            ) p
                                on p1.SSN_ID = p.SSN_ID
                        ) d
                        cross apply 
                        (
                            select 'Family_details', Family_details, Family_members_name, 1 union all
                            select 'Address_type', Address_type, Address, 2 union all
                            select 'PhoneNumber_type', PhoneNumber_type, PhoneNumber, 3
                        ) c(orig, col, value, ord)
                    ) d
                    group by col, ord
                    order by ord, col
                    FOR XML PATH(''), TYPE
                    ).value('.', 'NVARCHAR(MAX)') ,1,1,'');


set @query = N'SELECT ' + @cols + N' from 
            (
                select SSN_ID,
                    Citizen_name,
                    Company, 
                    col, 
                    value
                from
                (
                    select 
                        p1.SSN_ID,
                        p1.Citizen_name,
                        p1.Company,
                        p2.Family_details,
                        p2.Family_members_name,
                        p3.Address_type,
                        p3.Address,
                        PhoneNumber_type = p.PhoneNumber_type + cast(p.rn as varchar(10)),
                        p.PhoneNumber
                    from Table_pivot_01 p1
                    left join Table_pivot_02 p2
                        on p1.SSN_ID = p2.SSN_ID
                    left join Table_pivot_03 p3
                        on p1.SSN_ID = p3.SSN_ID
                    left join
                    (
                        select SSN_ID, PhoneNumber_type, PhoneNumber,
                            rn = row_number() over(partition by SSN_ID, PhoneNumber_type order by SSN_ID, PhoneNumber_type)
                        from Table_pivot_03
                        where PhoneNumber_type <> ''''
                    ) p
                        on p1.SSN_ID = p.SSN_ID
                ) d
                cross apply 
                (
                    select ''Family_details'', Family_details, Family_members_name union all
                    select ''Address_type'', Address_type, Address union all
                    select ''PhoneNumber_type'', PhoneNumber_type, PhoneNumber
                ) c(orig, col, value)
            ) src
            pivot
            (
                max(value)
                for col in (' + @cols + N')
            ) p '

exec sp_executesql @query;

这是另一个demo。

将行记录转换为mySQL中的列

1 个答案: