Database dataset from updating Sxce fat
Information about the changes in a dataset is maintained in two ways: by flagging rows that indicate that they have changed (Row State), and by keeping multiple copies of a record (Data Row Version).By using this information, processes can determine what has changed in the dataset and can send appropriate updates to the data source.All your insertions, updates, and deletions will be effected by the single button.When you data bind dataset tables to controls on a Windows Form or XAML page, the data binding architecture does all the work for you.(A concurrency violation occurs when another user modifies a record in the data source after the dataset has been filled.) To make changes to an existing data row, add or update data in the individual columns.If the dataset contains constraints (such as foreign keys or non-nullable constraints), it's possible that the record can temporarily be in an error state as you update it.If your application never sends those changes back to the data source, then you're finished with the update.
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.
When merging datasets, you can pass a Boolean argument () that tells the Merge method whether to retain existing modifications in the target dataset.
If you aren't using data-bound controls, you have to manually call the method of the same Table Adapter (or data adapter) that you used to populate the dataset.
However, you can also use different adapters, for example, to move data from one data source to another or to update multiple data sources.
After you complete an update, you can re-enable constraint checking, which also re-enables update events and raises them.