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sqlsql-serverxmlt-sqlfor-xml

Query to get XML output for hierarchical data using FOR XML PATH in SQL Server


I have a table with columns NodeId, NodeName, ParentNodeId and I want to ouput entire table data in the form of Xml like the following using SQL query. I think FOR XML PATH mode in Sql server can be used to achieve this (I use SQL Server 2008) using recursion, but not sure how. Thanks in advance

<?xml version="1.0" encoding="utf-8" ?>
<Nodes>
  <Node Id="1" Name="node1">
    <Node Id="11" Name="node11">
      <Node Id="111" Name="node111" />
      <Node Id="112" Name="node112" />
    </Node>
  </Node>
  <Node Id="2" Name="node2">
    <Node Id="21" Name="node21">
      <Node Id="211" Name="node211" />
      <Node Id="212" Name="node212" />
    </Node>
  </Node>
</Nodes>

Solution

  • I solved it using a stored procedure and a recursive function. code shown below. (actually I wanted this to generate a menu xml, so the code is shown for the menu.

        CREATE PROCEDURE [dbo].[usp_GetMenu]
        AS
        BEGIN
            SET NOCOUNT ON;
    
            SELECT  dbo.fnGetMenuItems(MenuId)
            FROM    dbo.Menu
            WHERE   ParentMenuId IS NULL
            FOR XML PATH('MenuItems')
        END
        GO
    
    CREATE FUNCTION [dbo].[fnGetMenuItems]
    (
        @MenuId int
    )
    RETURNS XML
    WITH RETURNS NULL ON NULL INPUT
    AS
    BEGIN
    
        RETURN 
        (
            SELECT  MenuId AS "@Id"
                    , [Name] AS "@Name"
                    , [URL] AS "@URL"
                    , [Key] AS "@Key"
                    , [dbo].[fnGetMenuItems](MenuId)
            FROM    dbo.Menu
            WHERE   ParentMenuId = @MenuId
            FOR XML PATH('MenuItem'),TYPE
        )
    
    END
    GO