从SQL Server 2016检索复杂的XML

Question

Given these tables:

DECLARE @Documents TABLE
(
    document_id int,
    document_file varchar(200),
    description varchar(200),
    pages int,
    write_barcode bit
)

DECLARE @Data TABLE
(
    id int,
    tax_id varchar(100),
    bo_lgl_name varchar(200),
    document_id int,
    keydata varchar(100),
    field_name varchar(100),
    value varchar(100)
)

populated with this data:

INSERT INTO @Data VALUES (1, '123456789', 'Fred Flintstone', 269, Null, 'LastName', 'Smith')
INSERT INTO @Data VALUES (1, '123456789', 'Fred Flintstone', 269, Null, 'FirstName', 'Joe')
INSERT INTO @Data VALUES (1, '123456789', 'Fred Flintstone', 6, Null, 'TaxID', '123456789')
INSERT INTO @Data VALUES (1, '123456789', 'Fred Flintstone', 6, Null, 'Address', 'New York')

INSERT INTO @Data VALUES (2, '666666666', 'Barney Rubble', 269, Null, 'LastName', 'Jones')
INSERT INTO @Data VALUES (2, '666666666', 'Barney Rubble', 269, Null, 'FirstName', 'Fred')
INSERT INTO @Data VALUES (2, '666666666', 'Barney Rubble', 6, Null, 'TaxID', '987654321')
INSERT INTO @Data VALUES (2, '666666666', 'Barney Rubble', 6, Null, 'Address', 'Los Angeles')

INSERT INTO @Documents VALUES  (269, '8802.pdf', Null, Null, Null)
INSERT INTO @Documents VALUES  (6, 'Doclist.xsl', Null, Null, Null)

I'm trying to retrieve this XML:

<Documents>
  <Batch BatchID="1" BatchName="Fred Flintstone">
    <DocCollection>
      <Document DocumentID="269" FileName="8802.pdf" KeyData="">
        <MergeFields>
          <MergeField FieldName="LastName" Value="Smith" />
          <MergeField FieldName="LastName" Value="Joe" />
          <MergeField FieldName="TaxID" Value="123456789" />
          <MergeField FieldName="Address" Value="New York" />
        </MergeFields>
      </Document>
      <Document DocumentID="6" FileName="Doclist.xsl" KeyData="">
        <MergeFields>
          <MergeField FieldName="LastName" Value="Smith" />
          <MergeField FieldName="LastName" Value="Joe" />
          <MergeField FieldName="TaxID" Value="123456789" />
          <MergeField FieldName="Address" Value="New York" />
        </MergeFields>
      </Document>
    </DocCollection>
  </Batch>
  <Batch BatchID="2" BatchName="Barney Rubble">
    <DocCollection>
      <Document DocumentID="269" FileName="8802.pdf" KeyData="">
        <MergeFields>
          <MergeField FieldName="LastName" Value="Smith" />
          <MergeField FieldName="LastName" Value="Joe" />
          <MergeField FieldName="TaxID" Value="123456789" />
          <MergeField FieldName="Address" Value="New York" />
        </MergeFields>
      </Document>
      <Document DocumentID="6" FileName="Doclist.xsl" KeyData="">
        <MergeFields>
          <MergeField FieldName="LastName" Value="Smith" />
          <MergeField FieldName="LastName" Value="Joe" />
          <MergeField FieldName="TaxID" Value="123456789" />
          <MergeField FieldName="Address" Value="New York" />
        </MergeFields>
      </Document>
    </DocCollection>
  </Batch>
</Documents>

So far, this is my lame and pathetic SQL attempt:

SELECT t.id AS '@BatchID', t.bo_lgl_name AS '@BatchName',
    (

        SELECT
            t.document_id AS '@DocumentID',
            d.description AS '@DocName',
            ISNULL(t.KeyData, '') AS '@KeyData',
            (
                SELECT
                    t.document_id AS '@FieldName',
                    d.description AS '@Value'
                FROM @Data t2
                INNER JOIN @Documents d2 ON t2.document_id = d1.document_id
                WHERE t2.id = t1.id AND t2.document_id = t1.document_id
                FOR XML PATH('MergeField')
            ) AS 'MergeField'
        FROM @Data t1
        INNER JOIN @Documents d1 ON t1.document_id = d.document_id
        WHERE t1.id = t.id
        FOR XML PATH('Document'), TYPE

    ) AS 'DocCollection'
FROM @Data t
INNER JOIN @Documents d ON t.document_id = d.document_id
WHERE value IS NOT NULL
ORDER BY t.id, t.document_id
FOR XML PATH('Batch'), ROOT('Documents')

which gets me partly there but starts to fall apart when it comes to grouping tags under each heading. Not sure if its the JOINs in my SQL or something else. I've never tried anything this complex with SQL and XML before so it could very well be something silly.

What am I doing wrong?

Thanks

Carl

Answer 1

This should get you closer:

SELECT t.id AS '@BatchID', t.bo_lgl_name AS '@BatchName',
    (

        SELECT  
            t1.document_id AS '@DocumentID',
            d.description AS '@DocName',
            d.document_file as '@FileName',
            isnull(t1.keydata,'') as '@KeyData',
            (
                SELECT
                    t2.field_name AS '@FieldName',
                    t2.value AS '@Value'
                FROM @Data t2

                WHERE  t2.document_id = d.document_id
                FOR XML PATH('MergeField') , TYPE
            ) AS 'MergeField'
        FROM (SELECT DISTINCT document_id,id,keydata FROM @DATA) t1
        inner join @Documents d
        on d.document_id=t1.document_id and t.id=t1.id
        order by d.document_id
        FOR XML PATH('Document'), TYPE
    ) AS 'DocCollection'
FROM (select distinct id,bo_lgl_name from @Data where value is not null)  t
FOR XML PATH('Batch'), ROOT('Documents')

I am not sure how you want to get the suggested output. Taxid '123456789' is marked with document 6, but you list it with document 269?