Dataset tools in Visual Studio
Datasets and related classes are legacy .NET technologies from the early 2000s that enable applications to work with data in memory while the applications are disconnected from the database. They are especially useful for applications that enable users to modify data and persist the changes back to the database. Although datasets have proven to be a very successful technology, we recommend that new .NET applications use Entity Framework. Entity Framework provides a more natural way to work with tabular data as object models, and it has a simpler programming interface.
A DataSet object is an in-memory object that is essentially a mini-database. It contains DataTable, DataColumn, and DataRow objects in which you can store and modify data from one or more databases without having to maintain an open connection. The dataset maintains information about changes to its data, so updates can be tracked and sent back to the database when your application becomes reconnected.
Datasets and related classes are defined in the System.Data namespace in the .NET Framework class library. You can create and modify datasets dynamically in code. For more information about how to do that, see ADO.NET. The documentation in this section shows how to work with datasets by using Visual Studio designers. One thing to know: datasets that are made through designers use TableAdapter objects to interact with the database, whereas datasets that are made programmatically use DataAdapter objects. For information about creating datasets programmatically, see DataAdapters and DataReaders.
If your application needs to only read data from a database, and not perform updates, adds, or deletes, you can usually get better performance by using a DataReader object to retrieve data into a generic List object or another collection object. If you are displaying the data, you can data-bind the user interface to the collection.
Visual Studio provides a lot of tooling to simplify working with datasets. The basic end-to-end workflow is:
Use the Data Source window to create a new dataset from one or more data sources. Use the Dataset Designer to configure the dataset and set its properties. For example, you need to specify which tables from the data source to include, and which columns from each table. Choose carefully to conserve the amount of memory that the dataset will require. For more information, see Create and configure datasets.
Specify the relationships between the tables so that foreign keys are handled correctly. For more information, see Fill datasets by using TableAdapters.
Use the TableAdapter Configuration Wizard to specify the query or stored procedure that will populate the dataset, and what database operations (update, delete, and so on) to implement. For more information, see these topics:
Query and search the data in the dataset. For more information, see Query datasets. LINQ to DataSet enables LINQ (Language-Integrated Query) over data in a DataSet object. For more information, see LINQ to DataSet.
Use the Data Sources window to bind user-interface controls to the dataset or its individual columns, and to specify which columns are user-editable. For more information, see Bind controls to data in Visual Studio.
For information about datasets in N-tier applications, see Work with datasets in n-tier applications.