Truy vấn thay đổi net Tất cả các truy vấn trước đó trả lại tất cả những thay đổi trong khung thời gian yêu cầu. Nhưng đối với hoạt động nhiều ETL hoặc đồng bộ, chỉ có các giá trị ròng cuối cùng là cần thiết. Thay đổi dữ liệu ảnh chụp tự động có thể xác định được net, hoặc cuối cùng, các giá trị. | Part VIII Monitoring and Auditing Result StartLSN Operation DepartmentID Name GroupName 2009-03-07 19 49 insert 21 CDC New Row SQL Rocks 2009-03-07 19 49 insert 22 Test Two CDC Rocks 2009-03-07 19 49 update deleted 21 CDC New Row SQL Rocks 2009-03-07 19 49 update inserted 21 Changed Name SQL Rocks 2009-03-07 19 49 insert 23 Row Three PBM Rocks 2009-03-07 19 49 insert 24 Row Four TVP Rock 2009-03-07 19 49 update deleted 22 Test Two CDC Rocks 2009-03-07 19 49 update inserted 22 Test Two T-SQL Rocks 2009-03-07 19 49 delete 24 Row Four TVP Rock Querying net changes All the previous queries returned all the changes within the requested time frame. But for many ETL operations or synchronizations only the final net values are needed. Change data capture can automatically determine the net or final values. Use the function to return the net changes -- Querying Net Changes - all option SELECT _ start_lsn as StartLSN as Operation DepartmentID Name GroupName FROM -- net changes smallest greater than or equal 20090101 largest less than or equal 20091231 all as CDC JOIN VALUES 1 delete 2 insert 3 update deleted -- all update old option to view 4 update inserted as Operation OperationID Description ON CDC operation ORDER BY start_lsn Result StartLSN Operation DepartmentID Name GroupName 2009-03-07 19 49 insert 21 Changed Name SQL Rocks 2009-03-07 19 49 insert 23 Row Three PBM Rocks 2009-03-07 19 49 insert 22 Test Two T-SQL Rocks 1292 Change Data Capture 60 When querying net changes using Change Data Capture it s also possible to work with a column mask to determine whether a given column has changed. In the following query the all with mask option and .
