Merge branch 'feature/UpdateRelationships-synchronization' into develop

Updated `UpdateRelationships` to fully synchronize relationships

Previously, in order to update existing relationships, callers had to trigger `UpdateTopic`'s `@DeleteRelationships` flag—which would delete all relationships for that topic—and _then_ call `UpdateRelationships` with the final relationships set. This was wasteful, as often times the relationships will have overlap, or even be identical.

This issue is fixed with with the introduction of the `@DeleteUnmatched` parameter to the `UpdateRelationships` stored procedure (46ba436). By default, this parameter is set to `1` (enabled), though it can be optionally disabled if preferred, in which case `UpdateRelationships` will _add_ any missing relationships, but won't _delete_ any unmatched relationships. That might be useful for just appending new relationships, without worrying about passing current relationships. (I'd prefer the default to be `0` here, but that would break the public interface, so that change will need to wait until the next major version.)

Given that, we are also able to remove the `@DeleteRelationships` functionality from `UpdateTopic`. That said, since `@DeleteRelationships` is part of the public interface, we don't want to remove it as that would require that the `SqlTopicRepository` version be aligned with the database version—something we restrict to major releases, as part of semantic versioning. As such, we're keeping the `@DeleteRelationships` parameter, but removing the functionality (9b58a4b). If the database is up-to-date with this release, that will yield the same results as before. If the database isn't, it will still accept the `@DeleteRelationships` parameter, as expected, and behave as it used to.

Finally, the code from a previous update which avoided primary key constraint violations by deduplicating the insert was optimized to use a `LEFT JOIN` with the actual `Relationships` table instead of using  `@Existing_TopicIDs` as a temporary storage location, as user-defined, table-valued types have proven to be quite inefficient (e725077).

Author: JeremyCaney

OnTopic.Data.Sql.Database/Stored Procedures/DeleteTopic.sql

@@ -87,23 +87,23 @@ WHERE	RangeLeft
 --------------------------------------------------------------------------------------------------------------------------------
 DELETE	Attributes
 FROM	Attributes		Attributes
-INNER JOIN	@Topics                         Topics
-  ON	Topics.TopicId                  = Attributes.TopicID
+INNER JOIN	@Topics		Topics
+  ON	Topics.TopicId		= Attributes.TopicID
 
 DELETE	ExtendedAttributes
 FROM	ExtendedAttributes	ExtendedAttributes
-INNER JOIN	@Topics                         Topics
-  ON	Topics.TopicId                  = ExtendedAttributes.TopicID
+INNER JOIN	@Topics		Topics
+  ON	Topics.TopicId		= ExtendedAttributes.TopicID
 
 DELETE	Relationships
 FROM	Relationships		Relationships
-INNER JOIN	@Topics                         Topics
-  ON	Topics.TopicId                  = Relationships.Source_TopicID
+INNER JOIN	@Topics		Topics
+  ON	Topics.TopicId		= Relationships.Source_TopicID
 
 DELETE	Relationships
 FROM	Relationships		Relationships
-INNER JOIN	@Topics                         Topics
-  ON	Topics.TopicId                  = Relationships.Target_TopicID
+INNER JOIN	@Topics		Topics
+  ON	Topics.TopicId		= Relationships.Target_TopicID
 
 --------------------------------------------------------------------------------------------------------------------------------
 -- DELETE RANGE

OnTopic.Data.Sql.Database/Stored Procedures/UpdateRelationships.sql

@@ -7,26 +7,10 @@
 CREATE PROCEDURE [dbo].[UpdateRelationships]
 	@TopicID		INT	= -1,
 	@RelationshipKey	VARCHAR(255)	= 'related',
-	@RelatedTopics		TopicList	READONLY
+	@RelatedTopics		TopicList	READONLY,
+	@DeleteUnmatched	BIT	= 1
 AS
 
---------------------------------------------------------------------------------------------------------------------------------
--- DECLARE AND SET VARIABLES
-
-DECLARE	@Existing_TopicIDs	TopicList
-
---------------------------------------------------------------------------------------------------------------------------------
--- IDENTIFY EXISTING VALUES
---------------------------------------------------------------------------------------------------------------------------------
-INSERT
-INTO	@Existing_TopicIDs (
-	  TopicID
-	)
-SELECT	Target_TopicID
-FROM	Relationships
-WHERE	Source_TopicID		= @TopicID
-  AND	RelationshipKey		= @RelationshipKey
-
 --------------------------------------------------------------------------------------------------------------------------------
 -- INSERT NOVEL VALUES
 --------------------------------------------------------------------------------------------------------------------------------
@@ -36,13 +20,27 @@ INTO	Relationships (
 	  RelationshipKey,
 	  Target_TopicID
 	)
-SELECT	@TopicId,
+SELECT	@TopicID,
 	@RelationshipKey,
-	Target.TopicID
+	TopicID
 FROM	@RelatedTopics		Target
-FULL JOIN	@Existing_TopicIDs	Existing
-  ON	Existing.TopicID	= Target.TopicID
-WHERE	Existing.TopicID	is null
+LEFT JOIN	Relationships		Existing
+  ON	Target_TopicID		= TopicID
+  AND	Source_TopicID		= @TopicID
+WHERE	Target_TopicID		IS NULL
+
+--------------------------------------------------------------------------------------------------------------------------------
+-- DELETE UNMATCHED VALUES
+--------------------------------------------------------------------------------------------------------------------------------
+IF @DeleteUnmatched = 1
+  BEGIN
+    DELETE	EXISTING
+    FROM	@RelatedTopics		Relationships
+    RIGHT JOIN	Relationships		Existing
+      ON	Target_TopicID		= TopicID
+    WHERE	Source_TopicID		= @TopicID
+      AND	ISNULL(TopicID, '')	= ''
+  END
 
 --------------------------------------------------------------------------------------------------------------------------------
 -- RETURN TOPIC ID

OnTopic.Data.Sql.Database/Stored Procedures/UpdateTopic.sql

@@ -99,16 +99,6 @@ CROSS APPLY (
 WHERE	IsNull(AttributeValue, '')	= ''
   AND	ExistingValue		!= ''
 
---------------------------------------------------------------------------------------------------------------------------------
--- REMOVE EXISTING RELATIONS
---------------------------------------------------------------------------------------------------------------------------------
--- Relationships will be re-added by the Data Access Layer using Topics_PersistRelationships.
---------------------------------------------------------------------------------------------------------------------------------
-DELETE
-FROM	[dbo].[Relationships]
-WHERE	Source_TopicID		= @TopicID
-  AND	@DeleteRelationships	= 1
-
 --------------------------------------------------------------------------------------------------------------------------------
 -- RETURN TOPIC ID
 --------------------------------------------------------------------------------------------------------------------------------

OnTopic.Data.Sql.Database/Utilities/Stored Procedures/GenerateNestedSet.sql

@@ -118,7 +118,7 @@ BEGIN
 END; -- while
 
 SELECT	Stack_Top,
-	TopicId,
+	TopicID,
 	RangeLeft,
 	RangeRight
 FROM	Topics