When merging datasets, you can pass a Boolean argument () that tells the Merge method whether to retain existing modifications in the target dataset.Because datasets maintain multiple versions of records, it's important to keep in mind that more than one version of the records is being merged.Using this method we ensure that we only update the records that were actually modified.
If you do send the changes back to the database, then a second step is required.
If you aren't using data-bound controls, then you have to manually call the Update method of the same Table Adapter (or data adapter) that you used to populate the dataset.
Merging datasets is useful when you have a local dataset and you get a second dataset from another application.
It's also useful when you get a second dataset from a component such as an XML web service, or when you need to integrate data from multiple datasets.
The first step is to update the dataset with new records, changed records, or deleted records.
If your application never sends those changes back to the data source, then you are finished with the update.Now we could just place an UPDATE command within the repeat region, so that when the form is submitted the command will update every record as the code loops through. Let's suppose that we display 40 records and only change 3 of them, the code still loops through and updates all 40 records, 37 of them with exactly the same values as they had previously.So I've used some client side Java Script and created a function that creates a list of the records that were actually changed.The following table shows how a record in two datasets is merged: dataset.This means that if you try to update the original data source with the target dataset, it might not be able to find the original row to update.Data Row Collection property when adding or removing rows.