Question

我有一个数据集，如下所示：

Column1 (PK) | Attribute | Value
1            | Name      | Carl
1            | Jobtitle  | Driver
2            | Name      | Lisa
2            | Age       | 15
3            | Name      | Jon
3            | Age       | 43
3            | Jobtitle  | Programmer

由于属性是任意的，因此不能在单独的列中将它们适当地原子化。数据集可能会变得非常庞大。

我希望有一个输出，它将所有属性融合在一起，变得像这样：

结果集

Column1 (PK) | FusionedAttributes
1            | Name = Carl, Jobtitle = Driver
2            | Name = Lisa, Age = 15
3            | Name = Jon, Age = 43, Jobtitle = Programmer

我已经尝试了UNION和子查询的方式，但是我不会出来。结果的组合也可以在底层的编程语言中实现，但是出于性能方面的考虑，我认为让SQL-Server进行工作将是一件很棒的事情，因为根据我的外行理解，这些引擎针对评估庞大的数据集进行了优化，远不止于此。我能够创建的算法。

有可能这样做吗？

Answer 1

您不能高效地执行此操作，但是您可以执行以下操作：

select c.id,
       stuff( (select concat(', ', attribute, ' = ', value)
               from t t2
               where t2.id = c.id
               for xml path(''), type).value('.', 'nvarchar(max)')
              ), 1, 2, ''
            ) as FusionedAttributes 
from (select distinct column1 from t) c;

Answer 2

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      </div>
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      <div class="col-xs-9">
        <div class="result-container">
          <input type="text" class="form-control" disabled>
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          <span class="glyphicon glyphicon-remove"></span>
        </button>
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    <div class="row">
      <div class="col-xs-3">
        <button type="button" class="btn btn-default btn-block" value="1" id="number-one-btn">
          1
        </button>
      </div>
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        <button type="button" class="btn btn-default btn-block" value="2" id="number-two-btn">
          2
        </button>
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  <div id="foo-container">
    <div class="confirmation-box">
      <div class="btn-group btn-group-lg" role="group" aria-label="...">
        <button type="button" class="btn btn-success positive">Yes</button>
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      <button type="button" class="btn btn-lg btn-danger init-confirm" disabled>Confirm?</button>
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      <button class="btn btn-lg btn-default">
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  <div class="clone-one">
    <button type="button" class="btn btn-lg btn-success">Clicky</button>
  </div>
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Answer 3

自2005年以来，SQL Server可以将数据作为复杂的XML返回。SQLServer 2016添加了JSON支持。以这些形式之一返回数据将使客户端应用程序更容易使用它而无需创建自己的解析器。它还将允许在其他T-SQL查询中使用这些值。

给出此表：

declare @foo table (
id int,
attribute varchar(20),
value varchar(20)
)

INSERT into @foo
VALUES
(1,'Name', 'Carl'),
(1,'Jobtitle', 'Driver'),
(2,'Name', 'Lisa'),
(2,'Age', '15'),
(3,'Name', 'Jon'),
(3,'Age', '43'),
(3,'Jobtitle  ', 'Programmer')

您可以使用以下方式将属性检索为XML：

select 
    f1.id, 
    ( select attribute as name,value 
      from @foo attribute 
      where attribute.id=f1.id 
      for xml auto,type,Root('record'))
from @foo f1
group by f1.id

这将返回：

id  DataAsXML
1   <record><attribute name="Name" value="Carl" /><attribute name="Jobtitle" value="Driver" /></record>
2   <record><attribute name="Name" value="Lisa" /><attribute name="Age" value="15" /></record>
3   <record><attribute name="Name" value="Jon" /><attribute name="Age" value="43" /><attribute name="Jobtitle  " value="Programmer" /></record>

通过Keycolumns合并大型数据集

3 个答案: