Refactored GetAttributes as user-defined, table-valued function

This doesn't impact backward compatibility, in that the function can still be called as a stored procedure. But it provides more flexibility in how the code is integrated with queries. For instance, it can now be used in a `CROSS APPLY` to retrieve attributes from `TopicID`s in another query.

Author: JeremyCaney

OnTopic.Data.Sql.Database/Stored Procedures/GetAttributes.sql renamed to OnTopic.Data.Sql.Database/Functions/GetAttributes.sql

@@ -1,45 +1,65 @@
 --------------------------------------------------------------------------------------------------------------------------------
--- GET TOPIC ATTRIBUTES
+-- GET ATTRIBUTES
 --------------------------------------------------------------------------------------------------------------------------------
 -- Returns the most recent value of each attribute associated with a particular topic.
 --------------------------------------------------------------------------------------------------------------------------------
-CREATE PROCEDURE [dbo].[GetAttributes]
+
+CREATE
+FUNCTION	[dbo].[GetAttributes] (
 	@TopicID		INT	= -1
+)
+RETURNS	@Attributes		TABLE
+(
+	AttributeKey		NVARCHAR(255)	NOT NULL,
+	AttributeValue		NVARCHAR(MAX)	NOT NULL,
+	IsExtendedAttribute	BIT,
+	Version		DATETIME
+)
 AS
 
---------------------------------------------------------------------------------------------------------------------------------
--- DECLARE AND SET VARIABLES
---------------------------------------------------------------------------------------------------------------------------------
-SET NOCOUNT ON;
+BEGIN
 
---------------------------------------------------------------------------------------------------------------------------------
--- SELECT MOST RECENT ATTRIBUTES
---------------------------------------------------------------------------------------------------------------------------------
-SELECT	AttributeKey,
+  --------------------------------------------------------------------------------------------------------------------------------
+  -- SETUP INSERT
+  --------------------------------------------------------------------------------------------------------------------------------
+  INSERT
+  INTO	@Attributes
+
+  --------------------------------------------------------------------------------------------------------------------------------
+  -- SELECT MOST RECENT ATTRIBUTES
+  --------------------------------------------------------------------------------------------------------------------------------
+  SELECT	AttributeKey,
 	AttributeValue,
 	0		AS IsExtendedAttribute,
 	Version
-FROM	AttributeIndex
-WHERE	TopicID		= @TopicID
+  FROM	AttributeIndex
+  WHERE	TopicID		= @TopicID
 
-UNION
+  UNION
 
---------------------------------------------------------------------------------------------------------------------------------
--- PARSE MOST RECENT EXTENDED ATTRIBUTES
---------------------------------------------------------------------------------------------------------------------------------
-SELECT	Attributes.Loc.value(
+  --------------------------------------------------------------------------------------------------------------------------------
+  -- PARSE MOST RECENT EXTENDED ATTRIBUTES
+  --------------------------------------------------------------------------------------------------------------------------------
+  SELECT	Attributes.Loc.value(
 	  '@key',
-	  'VARCHAR(255)'
+	  'VARCHAR(128)'
 	) AS		AttributeKey,
 	Attributes.Loc.value(
 	  '.[1]',
 	  'VARCHAR(MAX)'
 	) AS		AttributeValue,
 	1		AS IsExtendedAttribute,
 	Version
-FROM	ExtendedAttributeIndex
-CROSS APPLY	AttributesXml.nodes(
+  FROM	ExtendedAttributeIndex
+  CROSS APPLY	AttributesXml.nodes(
 	  '/attributes/attribute'
 	) AS		Attributes(Loc)
-WHERE	TopicID		= @TopicID
-ORDER BY	AttributeKey
+  WHERE	TopicID		= @TopicID
+  ORDER BY	AttributeKey
+
+  ------------------------------------------------------------------------------------------------------------------------------
+  -- RETURN
+  ------------------------------------------------------------------------------------------------------------------------------
+  RETURN
+
+END

OnTopic.Data.Sql.Database/OnTopic.Data.Sql.Database.sqlproj

@@ -89,6 +89,7 @@
     <Build Include="Utilities\Views\UniqueKeyIndex.sql" />
     <Build Include="Utilities\Views\LeftRightRange.sql" />
     <Build Include="Utilities\Tables\AdjacencyList.sql" />
+    <Build Include="Functions\GetAttributes.sql" />
   </ItemGroup>
   <ItemGroup>
     <Build Include="Tables\ExtendedAttributes.sql" />
@@ -105,7 +106,6 @@
     <Build Include="Stored Procedures\UpdateTopic.sql" />
     <Build Include="Stored Procedures\UpdateRelationships.sql" />
     <Build Include="Stored Procedures\GetTopics.sql" />
-    <Build Include="Stored Procedures\GetAttributes.sql" />
     <Build Include="Stored Procedures\DeleteTopic.sql" />
     <Build Include="Stored Procedures\CreateTopic.sql" />
     <Build Include="Stored Procedures\GetTopicVersion.sql" />