(SQL Server) Iterate over Direct Child Nodes by Index

Demonstrates some ways to iterate over direct child nodes by index.

The input XML, available at http://www.chilkatsoft.com/data/get_child.xml, is this:

<root>
    <fruit color="red">apple</fruit>
    <fruit color="green">pear</fruit>
    <veg color="orange">carrot</veg>
    <meat animal="cow">beef</meat>
    <xyz>
        <fruit color="blue">blueberry</fruit>
        <veg color="green">broccoli</veg>
    </xyz>
    <fruit color="purple">grape</fruit>
    <cheese color="yellow">cheddar</cheese>
</root>

Download Chilkat XML ActiveX

CREATE PROCEDURE ChilkatSample
AS
BEGIN
    DECLARE @hr int
    DECLARE @iTmp0 int
    DECLARE @sTmp0 nvarchar(4000)
    DECLARE @sTmp1 nvarchar(4000)
    DECLARE @xml int
    EXEC @hr = sp_OACreate 'Chilkat.Xml', @xml OUT
    IF @hr <> 0
    BEGIN
        PRINT 'Failed to create ActiveX component'
        RETURN
    END

    DECLARE @child int

    DECLARE @success int

    --  The sample input XML is available at http://www.chilkatsoft.com/data/get_child.xml
    EXEC sp_OAMethod @xml, 'LoadXmlFile', @success OUT, 'get_child.xml'
    IF @success <> 1
      BEGIN
        EXEC sp_OAGetProperty @xml, 'LastErrorText', @sTmp0 OUT

        PRINT @sTmp0
        RETURN
      END

    --  The NumChildren property contains the number of direct
    --  child nodes.  Note: The child nodes under "xyz" are NOT
    --  direct children of "root".  Therefore, the "root" node has
    --  7 direct children

    EXEC sp_OAGetProperty @xml, 'NumChildren', @iTmp0 OUT

    PRINT 'NumChildren = ' + @iTmp0

    --  Iterate over the direct children by index. The first child
    --  is at index 0.
    DECLARE @i int

    EXEC sp_OAGetProperty @xml, 'NumChildren', @iTmp0 OUT
    SELECT @i = 0
    WHILE @i <= @iTmp0 - 1
      BEGIN
        --   access the tag and content directly by index:


        EXEC sp_OAMethod @xml, 'GetChildTagByIndex', @sTmp0 OUT, @i

        EXEC sp_OAMethod @xml, 'GetChildContentByIndex', @sTmp1 OUT, @i
        PRINT STR(@i) + ': ' + @sTmp0 + ' : ' + @sTmp1

        SELECT @i = @i + 1
      END

    PRINT '-----'

    --  Do the same as the above loop, but get the child node
    --  and access the Tag and Content properties:
    EXEC sp_OAGetProperty @xml, 'NumChildren', @iTmp0 OUT
    SELECT @i = 0
    WHILE @i <= @iTmp0 - 1
      BEGIN
        EXEC sp_OAMethod @xml, 'GetChild', @child OUT, @i


        EXEC sp_OAGetProperty @child, 'Tag', @sTmp0 OUT


        EXEC sp_OAGetProperty @child, 'Content', @sTmp1 OUT

        PRINT STR(@i) + ': ' + @sTmp0 + ' : ' + @sTmp1

        SELECT @i = @i + 1
      END

    PRINT '-----'

    --  Do the same as the above loop, but instead of creating
    --  a new object instance for each child, call GetChild2 to
    --  update the object's reference instead.
    EXEC sp_OAGetProperty @xml, 'NumChildren', @iTmp0 OUT
    SELECT @i = 0
    WHILE @i <= @iTmp0 - 1
      BEGIN
        --  Navigate to the Nth child.
        EXEC sp_OAMethod @xml, 'GetChild2', NULL, @i


        EXEC sp_OAGetProperty @xml, 'Tag', @sTmp0 OUT


        EXEC sp_OAGetProperty @xml, 'Content', @sTmp1 OUT

        PRINT STR(@i) + ': ' + @sTmp0 + ' : ' + @sTmp1
        --  Navigate back up to the parent:
        EXEC sp_OAMethod @xml, 'GetParent2', NULL
        SELECT @i = @i + 1
      END

    PRINT '-----'

    --  Notice that the Content of the "xyz" node is empty.  This is correct.
    --  The "xyz" node has no Content, but 2 direct children.

END
GO