Specify a Merge Article Resolver
Applies to:
SQL Server
This topic describes how to specify a merge article resolver in SQL Server by using SQL Server Management Studio or Transact-SQL.
Recommendations
Merge replication allows the following types of article resolvers:
The default resolver. The behavior of the default resolver depends on whether the subscription is a client subscription or a server subscription. For more information about specifying subscription type, see Specify a Merge Subscription Type and Conflict Resolution Priority (SQL Server Management Studio).
A custom resolver you have written, which can be a business logic handler (written in managed code) or a custom COM-based resolver. For more information, see Advanced Merge Replication Conflict Detection and Resolution. If you need to implement custom logic that is executed for each replicated row, not just for conflicting rows, see Implement a Business Logic Handler for a Merge Article.
A standard COM-based resolver, which is included with Microsoft SQL Server.
To use a resolver other than the default resolver, you must copy the resolver to the computer on which the Merge Agent runs and register it (if you are using a business logic handler, it must also be registered at the Publisher). The Merge Agent runs at:
The Distributor for a push subscription
The Subscriber for a pull subscription
The Microsoft Internet Information Services (IIS) server for a pull subscription that uses Web synchronization
Using SQL Server Management Studio
After the resolver is registered, specify that an article should use the resolver on the Resolver tab of the Article Properties - <Article> dialog box, which is available in the New Publication Wizard and the Publication Properties - <Publication> dialog box. For more information about using the wizard and accessing the dialog box, see Create a Publication and View and Modify Publication Properties.
To specify a resolver
On the Articles page of the New Publication Wizard or the Publication Properties - <Publication> dialog box, select a table.
Click Article Properties, and then click Set Properties of Highlighted Table Article.
On the Article Properties - <Article> page, click the Resolver tab.
Select Use a custom resolver (registered at the Distributor), and then in the list, click the resolver.
If the resolver requires input (such as a column name), specify it in the Enter information needed by the resolver text box.
Select OK.
Repeat this process for each article that requires a resolver.
Using Transact-SQL
To register a custom conflict resolver
If you plan to register your own custom conflict resolver, create one of the following types:
Managed code-based resolver as a business logic handler. For more information, see Implement a Business Logic Handler for a Merge Article.
Stored procedure-based resolver and COM-based resolver. For more information, see Implement a Custom Conflict Resolver for a Merge Article.
To determine if the desired resolver is already registered, execute sp_enumcustomresolvers (Transact-SQL) at the Publisher on any database. This displays a description of the custom resolver as well as the class identifier (CLSID) for each COM-based resolver registered at the Distributor or information on the managed assembly for each business logic handler registered at the Distributor.
If the desired custom resolver is not already registered, execute sp_registercustomresolver (Transact-SQL) at the Distributor. Specify a name for the resolver for @article_resolver; for a business logic handler, this is the friendly name of the assembly. For COM-based resolvers, specify the CLSID of the DLL for @resolver_clsid, and for a business logic handler, specify a value of true for @is_dotnet_assembly, the name of the assembly for @dotnet_assembly_name, and the fully-qualified name of the class that overrides BusinessLogicModule for @dotnet_class_name.
Note
If a business logic handler assembly is not deployed in the same directory as the Merge Agent executable, in the same directory as the application that synchronously starts the Merge Agent, or in the global assembly cache (GAC), you need to specify the full path with the assembly name for @dotnet_assembly_name.
If the resolver is a COM-based resolver:
Copy the custom resolver DLL to the Distributor for push subscriptions or to the Subscriber for pull subscriptions.
Note
Microsoft custom resolvers can be found in the C:\Program Files\Microsoft SQL Server\nnn\COM directory.
Use regsvr32.exe to register the custom resolver DLL with the operating system. For example, executing the following from the command prompt registers the SQL Server Additive Conflict Resolver:
regsvr32 ssradd.dll
If the resolver is a business logic handler, deploy the assembly in the same folder as the Merge Agent executable (replmerg.exe), in the same folder as an application that invokes the Merge Agent, or in the folder specified for the @dotnet_assembly_name parameter in step 3.
Note
The default installation location of the Merge Agent executable is C:\Program Files\Microsoft SQL Server\nnn\COM.
Specify a custom resolver when defining a merge article
If you plan to use a custom conflict resolver, create and register the resolver using the above procedure.
At the Publisher, execute sp_enumcustomresolvers (Transact-SQL) and note the name of the desired custom resolver in the value field of result set.
At the Publisher on the publication database, execute sp_addmergearticle (Transact-SQL). Specify the name of the resolver from step 2 for @article_resolver and any required input to the custom resolver using the @resolver_info parameter. For stored procedure-based custom resolvers, @resolver_info is the name of the stored procedure. For more information about required input for resolvers supplied by Microsoft, see Microsoft COM-Based Resolvers.
Specify or change a custom resolver for an existing merge article
To determine if a custom resolver has been defined for an article, or to get the name of the resolver, execute sp_helpmergearticle (Transact-SQL). If there is a custom resolver defined for the article, its name will be displayed in the article_resolver field. Any input supplied to the resolver will be displayed in the resolver_info field of the result set.
At the Publisher, execute sp_enumcustomresolvers (Transact-SQL) and note the name of the desired custom resolver in the value field of the result set.
At the Publisher on the publication database, execute sp_changemergearticle (Transact-SQL). Specify a value of article_resolver, including the full path for business logic handlers, for @property, and the name of the desired custom resolver from step 2 for @value.
To change any required input for the custom resolver, execute sp_changemergearticle (Transact-SQL) again. Specify a value of resolver_info for @property and any required input to the custom resolver for @value. For stored procedure-based custom resolvers, @resolver_info is the name of the stored procedure. For more information about required input, see Microsoft COM-Based Resolvers.
Unregister a custom conflict resolver
At the Publisher, execute sp_enumcustomresolvers (Transact-SQL) and note the name of the custom resolver to remove in the value field of the result set.
Execute sp_unregistercustomresolver (Transact-SQL) at the Distributor. Specify the full name of the custom resolver from step 1 for @article_resolver.
Examples (Transact-SQL)
This example creates a new article and specifies that the SQL Server Averaging Conflict Resolver be used to calculate the average of the UnitPrice column when conflicts occur.
DECLARE @publication AS sysname;
DECLARE @article AS sysname;
SET @publication = 'AdvWorksSalesOrdersMerge';
SET @article = 'Products';
EXEC sp_addmergearticle
@publication = @publication,
@article = @article,
@source_object = @article,
@article_resolver = 'Microsoft SQL Server Averaging Conflict Resolver',
@resolver_info = 'UnitPrice';
GO
This example changes an article to specify using the SQL Server Additive Conflict Resolver to calculate the sum of the UnitsOnOrder column when conflicts occur.
DECLARE @publication AS sysname;
DECLARE @article AS sysname;
SET @publication = 'AdvWorksSalesOrdersMerge';
SET @article = 'Products';
EXEC sp_changemergearticle
@publication = @publication,
@article = @article,
@property='article_resolver',
@value='Microsoft SQL Server Additive Conflict Resolver';
EXEC sp_changemergearticle
@publication = @publication,
@article = @article,
@property='resolver_info',
@value='UnitsOnOrder';
GO
See Also
Advanced Merge Replication Conflict Detection and Resolution
Implement a Business Logic Handler for a Merge Article