sql-serverxmlsqlxmlxquery-sqlshred

Shredding XML column data into rows in SQL


I have an xml value

<ITEMS>
<ITEM><ID>1</ID><NAME>John</NAME></ITEM>
<ITEM><ID>5</ID><NAME>James</NAME></ITEM>
</ITEMS>

I am able to shred the above xml into tables of ID and Name column using the below query

Declare @X xml
select x.r.value('(ID)[1]','int') as [ID],
       x.r.value('(DATA)[1]','VARCHAR(100)') AS [DATA]
FROM @X.nodes ('/ITEMS/ITEM') AS x(r)

But how will i able to do this when the above xml is present in a row.

S.No   COMPANY        DATA
 1      ABC      </ITEMS><ITEM><ID>1</ID><NAME>John</Name>....

I need to populate like below

S.No   COMPANY    ID     NAME
 1      ABC        1    John
 2      ABC        5    James

Note : The Data column in the table is of varchar data type and not xml data type.


Solution

  • First, you can use a CTE to convert it to XML data type. Second way is via a derived table.

    SQL

    -- DDL and sample data population, start
    DECLARE @tbl TABLE (SequentialNo INT PRIMARY KEY, Company VARCHAR(20), [DATA] VARCHAR(MAX));
    INSERT INTO @tbl (SequentialNo, Company, [DATA])
    VALUES
    (1, 'ABC', '<ITEMS>
        <ITEM>
            <ID>1</ID>
            <NAME>John</NAME>
        </ITEM>
        <ITEM>
            <ID>5</ID>
            <NAME>James</NAME>
        </ITEM>
    </ITEMS>');
    -- DDL and sample data population, end
    
    -- Method #1
    -- CTE
    ;WITH rs AS
    (
       SELECT *, TRY_CAST([DATA] AS XML) AS [xmldata]
       FROM @tbl
    )
    SELECT SequentialNo
        , Company
        , col.value('(ID/text())[1]','INT') AS ID
        , col.value('(NAME/text())[1]','VARCHAR(40)') AS [Name]
    FROM rs AS tbl
        CROSS APPLY tbl.[xmldata].nodes('/ITEMS/ITEM') AS tab(col);
    
    -- Method #2
    -- Derived table
    SELECT SequentialNo
        , Company
        , col.value('(ID/text())[1]','INT') AS ID
        , col.value('(NAME/text())[1]','VARCHAR(40)') AS [Name]
    FROM (SELECT *, TRY_CAST([DATA] AS XML) AS [xmldata]
       FROM @tbl) AS tbl
        CROSS APPLY tbl.[xmldata].nodes('/ITEMS/ITEM') AS tab(col);
    

    Output

    +--------------+---------+----+-------+
    | SequentialNo | Company | ID | Name  |
    +--------------+---------+----+-------+
    |            1 | ABC     |  1 | John  |
    |            1 | ABC     |  5 | James |
    +--------------+---------+----+-------+