SqlDataAdapter Class

The SqlDataAdapter, serves as a bridge between a DataSet and SQL Server for retrieving and saving data. The SqlDataAdapter provides this bridge by mapping Fill, which changes the data in the DataSet to match the data in the data source, and Update, which changes the data in the data source to match the data in the DataSet, using the appropriate Transact-SQL statements against the data source. The update is performed on a by-row basis. For every inserted, modified, and deleted row, the Update method determines the type of change that has been performed on it (Insert, Update, or Delete). Depending on the type of change, the Insert, Update, or Delete command template executes to propagate the modified row to the data source. When the SqlDataAdapter fills a DataSet, it creates the necessary tables and columns for the returned data if they do not already exist. However, primary key information is not included in the implicitly created schema unless the MissingSchemaAction property is set to AddWithKey. You may also have the SqlDataAdapter create the schema of the DataSet, including primary key information, before filling it with data using FillSchema. For more information, see Adding Existing Constraints to a DataSet.

SqlDataAdapter is used in conjunction with SqlConnection and SqlCommand to increase performance when connecting to a SQL Server database.

Note
If you are using SQL Server stored procedures to edit or delete data using a DataAdapter, make sure that you do not use SET NOCOUNT ON in the stored procedure definition. This causes the rows affected count returned to be zero, which the DataAdapter interprets as a concurrency conflict. In this event, a DBConcurrencyException will be thrown.

The SqlDataAdapter also includes the SelectCommand, InsertCommand, DeleteCommand, UpdateCommand, and TableMappings properties to facilitate the loading and updating of data.

When an instance of SqlDataAdapter is created, the read/write properties are set to initial values. For a list of these values, see the SqlDataAdapter constructor.

The InsertCommand, DeleteCommand, and UpdateCommand are generic templates that are automatically filled with individual values from every modified row through the parameters mechanism.

For every column that you propagate to the data source on Update, a parameter should be added to the InsertCommand, UpdateCommand, or DeleteCommand. The SourceColumn property of the DbParameter object should be set to the name of the column. This setting indicates that the value of the parameter is not set manually, but is taken from the particular column in the currently processed row.

Note
An InvalidOperationException will occur if the Fill method is called and the table contains a user-defined type that is not available on the client computer. For more information, see Creating and Using User-Defined Types in SQL Server Books Online.

The following example uses the SqlCommand, SqlDataAdapter, and SqlConnection to select records from a database and populate a DataSet with the selected rows. The filled DataSet is then returned. To accomplish this, the method is passed an initialized DataSet, a connection string, and a query string that is a Transact-SQL SELECT statement.

private static DataSet SelectRows(DataSet dataset,
    string connectionString,string queryString) 
{
    using (SqlConnection connection = 
        new SqlConnection(connectionString))
    {
        SqlDataAdapter adapter = new SqlDataAdapter();
        adapter.SelectCommand = new SqlCommand(
            queryString, connection);
        adapter.Fill(dataset);
        return dataset;
    }
}

.NET Framework

.NET Framework Client Profile

Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

Reference

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