I want to know if the rows have changed values in my Datatable, how to check that? I got a Datatable has data and I make some changes on this data by grid view so Can I check which rows have changed.

CodePudding user response：

Each DataRow has a RowState. When you populate a DataTable by calling Fill on a data adapter, all rows start out Unchanged. When you add a row the value will be Added, when you edit an existing row the value will be Modified and when you delete an existing row the value will be Deleted.

Note that, when you call Fill on a data adapter, the rows will be initially added with a RowState of Added but then AcceptChanges is called and they will all be set to Unchanged. If you set AcceptChangesDuringFill to False first, they will all remain Added. This is useful when, for instance, you want to retrieve from one database and then insert into another.

When you call Update on a data adapter to save changes, AcceptChanges is called afterwards and all Added and Modified rows become Unchanged and all Deleted rows are removed. If you set AcceptChangesDuringUpdate to False first, they will all remain as they were. This is useful when, for instance, you want to save changes to multiple tables from one DataTable. You would then call AcceptChanges manually if you wanted to keep using the DataTable.

Note that each DataRow contains two versions of its data: original and current. When you get data from a field in a DataRow you will get the current version by default, but you can specify which version you want. If the RowState is Added then the original version is empty and, if the the RowState is Deleted then the current version is empty. When AcceptChanges is called, the current version is copied over the original version in rows that were Added or Modified.

You can also call GetChanges on a DataTable and that will either return Nothing or a new DataTable containing just the changed rows. You can also specify one or more DataRowState values and get just changes of that type.