How to: Define and Modify a Parameterized Row Filter for a Merge Article (Replication Transact-SQL Programming)
When creating table articles, you can use parameterized row filters. These filters use a WHERE clause to select the appropriate data to be published. Rather than specifying a literal value in the clause (as you do with a static row filter), you specify one or both of the following system functions: SUSER_SNAME and HOST_NAME. For more information, see Parameterized Row Filters. Parameterized row filters can be created and modified programmatically using replication stored procedures.
To define a parameterized row filter for an article in a merge publication
At the Publisher on the publication database, execute sp_addmergearticle (Transact-SQL). Specify @publication, a name for the article for @article, the table being published for @source_object, the WHERE clause that defines the parameterized filter for @subset_filterclause (not including WHERE), and one of the following values for @partition_options, which describes the type of partitioning that will result from the parameterized row filter:
0 - Filtering for the article either is static or does not yield a unique subset of data for each partition (an "overlapping" partition).
1 - Resulting partitions are overlapping, and updates made at the Subscriber cannot change the partition to which a row belongs.
2 - Filtering for the article yields nonoverlapping partitions, but multiple Subscribers can receive the same partition.
3 - Filtering for the article yields nonoverlapping partitions that are unique for each subscription.
To change a parameterized row filter for an article in a merge publication
At the Publisher on the publication database, execute sp_changemergearticle. Specify @publication, @article, a value of subset_filterclause for @property, the expression that defines the parameterized filter for @value (not including WHERE), and a value of 1 for both @force_invalidate_snapshot and @force_reinit_subscription.
If this change results in different partitioning behavior, then execute sp_changemergearticle again. Specify @publication, @article, a value of partition_options for @property, and the most appropriate partitioning option for @value, which can be one of the following:
0 - Filtering for the article either is static or does not yield a unique subset of data for each partition (an "overlapping" partition).
1 - Resulting partitions are overlapping, and updates made at the Subscriber cannot change the partition to which a row belongs.
2 - Filtering for the article yields nonoverlapping partitions, but multiple Subscribers can receive the same partition.
3 - Filtering for the article yields nonoverlapping partitions that are unique for each subscription.
This example defines a group of articles in a merge publication where the articles are filtered with a series of join filters against the Employee table that is itself filtered using a parameterized row filter on the LoginID column. During synchronization, the value returned by the HOST_NAME function is overridden. For more information, see Overriding the HOST_NAME() Value in the topic Parameterized Row Filters.
-- To avoid storing the login and password in the script file, the value -- is passed into SQLCMD as a scripting variable. For information about -- how to use scripting variables on the command line and in SQL Server -- Management Studio, see the "Executing Replication Scripts" section in -- the topic "Programming Replication Using System Stored Procedures". --Add a new merge publication. DECLARE @publicationdb AS sysname; DECLARE @publication AS sysname; DECLARE @table1 AS sysname; DECLARE @table2 AS sysname; DECLARE @filter AS sysname; DECLARE @schema_hr AS sysname; DECLARE @schema_sales AS sysname; SET @publicationdb = N'AdventureWorks2008R2'; SET @publication = N'AdvWorksSalesPersonMerge'; SET @table1 = N'Employee'; SET @table2 = N'SalesPerson'; SET @filter = N'SalesPerson_Employee'; SET @schema_hr = N'HumanResources'; SET @schema_sales = N'Sales'; USE [AdventureWorks2008R2]; -- Enable AdventureWorks2008R2 for merge replication. EXEC sp_replicationdboption @dbname = @publicationdb, @optname = N'merge publish', @value = N'true'; -- Create new merge publication with Subscriber requested snapshot -- and using the default agent schedule. EXEC sp_addmergepublication @publication = @publication, @description = N'Merge publication of AdventureWorks2008R2.', @allow_subscriber_initiated_snapshot = N'true', @publication_compatibility_level = N'90RTM'; -- Create a new snapshot job for the publication, using the default schedule. -- Pass credentials at runtime using sqlcmd scripting variables. EXEC sp_addpublication_snapshot @publication = @publication, @job_login = $(login), @job_password = $(password); -- Add an article for the Employee table, -- which is horizontally partitioned using -- a parameterized row filter. EXEC sp_addmergearticle @publication = @publication, @article = @table1, @source_owner = @schema_hr, @source_object = @table1, @type = N'table', @description = 'contains employee information', @subset_filterclause = N'[LoginID] = HOST_NAME()'; -- Add an article for the SalesPerson table, -- which is partitioned based on a join filter. EXEC sp_addmergearticle @publication = @publication, @article = @table2, @source_owner = @schema_sales, @source_object = @table2, @type = N'table', @description = 'contains salesperson information'; -- Add a join filter between the two articles. EXEC sp_addmergefilter @publication = @publication, @article = @table1, @filtername = @filter, @join_articlename = @table2, @join_filterclause = N'[Employee].[BusinessEntityID] = [SalesPerson].[SalesPersonID]', @join_unique_key = 1, @filter_type = 1; GO -- Start the agent job to generate the full snapshot for the publication. -- The filtered data snapshot is generated automatically the first time -- the subscription is synchronized. DECLARE @publication AS sysname; SET @publication = N'AdvWorksSalesPersonMerge'; EXEC sp_startpublication_snapshot @publication = @publication; GO
