Databases Reference
In-Depth Information
Applying a Filter
The table and columns have been selected. At this point the dataset could be complete, but for this example a
filter will be applied. Applying a filter is quite easy. As shown in Figure
7-13
, click the Filter checkbox next to the
column you want to filter on and apply the row filtering criteria in the Row Filtering section. In this example the
BusinessEntityID column of the Person.BusinessEntity table has been selected. Enter a value of 10000 in the filter
Value field to filter all Persons with an
BusinessentityID
greater than 10,000.
Figure 7-13.
Row filtering
Querying the Person.BusinessEntity table in the hub database will reveal IDs 1 to 20777, which were added
during the creation of the database. Because of the filter applied to this sync group, only rows with BusinessEntityID
greater than 10,000 will be synchronized to the member databases.
Applying Conflict Resolution
Configuring the sync group is almost complete. The next step is to set the Conflict Resolution. A data conflict occurs
whenever the same data in two or more databases within a sync group is changed between synchronizations. In the
current release of SQL Data Sync you can select between two resolution policies: Hub Wins and Client Wins.
•
Hub Wins:
The first row change written to the hub is kept. Subsequent attempts to write to the
same row in the hub are ignored. The first write to the hub is propagated out to all member
databases.
•
Client Wins:
Each row change in a member database is written to the hub, overwriting prior
changes to the same row. The last write to the hub is then propagated out to all member
databases.
No matter which policy you adopt, one of the changed rows is kept and the others are lost whenever a
conflict arises.
