Processing ProcessParameters as XML in SQL Server - sql

Question

I am trying to extract values from an XML column. Unfortunately, whatever combination I try, I can't get any meaningfull result out of it.
A test script with data can be found here
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Example of the contents of one item
<Dictionary xmlns="clr-namespace:System.Collections.Generic;assembly=mscorlib" xmlns:mtbwa="clr-namespace:Microsoft.TeamFoundation.Build.Workflow.Activities;assembly=Microsoft.TeamFoundation.Build.Workflow" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" x:TypeArguments="x:String, x:Object">
<mtbwa:BuildSettings x:Key="BuildSettings" ProjectsToBuild="$/Projects/BpABA/Dev/V6/DUnit/FrameworkTests.dproj">
<mtbwa:BuildSettings.PlatformConfigurations>
<mtbwa:PlatformConfigurationList Capacity="1">
<mtbwa:PlatformConfiguration Configuration="Debug" Platform="Win32" />
</mtbwa:PlatformConfigurationList>
</mtbwa:BuildSettings.PlatformConfigurations>
</mtbwa:BuildSettings>
<mtbwa:SourceAndSymbolServerSettings SymbolStorePath="{x:Null}" x:Key="SourceAndSymbolServerSettings" />
<mtbwa:AgentSettings x:Key="AgentSettings" MaxExecutionTime="01:00:00" MaxWaitTime="04:00:00" Tags="Delphi 5" />
<x:Boolean x:Key="CreateWorkItem">False</x:Boolean>
<x:Boolean x:Key="PerformTestImpactAnalysis">False</x:Boolean>
</Dictionary>
Latest attempt
;WITH XMLNAMESPACES('http://schemas.microsoft.com/winfx/2006/xaml' AS mtbwa)
, q AS (
SELECT CAST(bd.ProcessParameters AS XML) p
FROM dbo.tbl_BuildDefinition bd
)
SELECT X.Doc.value('mtbwa:BuildSettings[0]', 'VARCHAR(50)') AS 'Test'
FROM q CROSS APPLY p.nodes('/mtbwa:Dictionary') AS X(Doc)
Background
The column ProcessParameters is part of the TFS build system in the tbl_BuildDefinition table.
The complete DDL is as follows
USE [Tfs_ProjectCollection]
GO
/****** Object: Table [dbo].[tbl_BuildDefinition] Script Date: 06/19/2012 16:28:56 ******/
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
CREATE TABLE [dbo].[tbl_BuildDefinition](
[DefinitionId] [int] IDENTITY(1,1) NOT NULL,
[GroupId] [int] NOT NULL,
[DefinitionName] [nvarchar](260) NOT NULL,
[ControllerId] [int] NOT NULL,
[DropLocation] [nvarchar](260) NULL,
[ContinuousIntegrationType] [tinyint] NOT NULL,
[ContinuousIntegrationQuietPeriod] [int] NOT NULL,
[LastBuildUri] [nvarchar](64) NULL,
[LastGoodBuildUri] [nvarchar](64) NULL,
[LastGoodBuildLabel] [nvarchar](326) NULL,
[Enabled] [bit] NOT NULL,
[Description] [nvarchar](2048) NULL,
[LastSystemQueueId] [int] NULL,
[LastSystemBuildStartTime] [datetime] NULL,
[ProcessTemplateId] [int] NOT NULL,
[ProcessParameters] [nvarchar](max) NULL,
[ScheduleJobId] [uniqueidentifier] NOT NULL,
CONSTRAINT [PK_tbl_BuildDefinition] PRIMARY KEY CLUSTERED
(
[GroupId] ASC,
[DefinitionName] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]
) ON [PRIMARY]
GO
ALTER TABLE [dbo].[tbl_BuildDefinition] ADD DEFAULT (newid()) FOR [ScheduleJobId]
GO

Answer 1

I think you have a wrong namespace defined for your mbtwa prefix in your XML/XQuery text, and you need to use 1-based indexing to get at the data when using the .value() function (not 0-based like commonly used).
So try this:
;WITH XMLNAMESPACES('clr-namespace:Microsoft.TeamFoundation.Build.Workflow.Activities;assembly=Microsoft.TeamFoundation.Build.Workflow' AS mtbwa,
DEFAULT 'clr-namespace:System.Collections.Generic;assembly=mscorlib')
, q AS (
SELECT CAST(bd.ProcessParameters AS XML) p
FROM dbo.tbl_BuildDefinition bd
WHERE DefinitionId = 1
)
SELECT
X.Doc.query('mtbwa:BuildSettings') AS 'Node',
X.Doc.value('(mtbwa:BuildSettings/#ProjectsToBuild)[1]', 'VARCHAR(50)') AS 'ProjectsToBuild'
FROM
q
CROSS APPLY
p.nodes('/Dictionary') AS X(Doc)
This should give you the whole <mtbwa:BuildSettings> node as XML (using the .query() function), as well as the value of the single attribute ProjectsToBuild ($/Projects/BpABA/Dev/V6/DUnit/FrameworkTests.dproj) of that node.
If you want a whole node (as XML), then you need to use .query('xpath') - the .value() function can get you the inner text of a node (if present), or the value of a single attribute.
Does that help at all?