The ADO.NET DataSet contains DataTableCollection and their DataRelationCollection. It represents a collection of data retrieved from the Data Source. We can use Dataset in combination with DataAdapter Class. The DataSet object offers disconnected data source architecture. The Dataset can work with the data without knowing the source of the data coming from. That is, the Dataset can work with a disconnected mode from its Data Source.

The Dataset contains the copy of the data requested. The Dataset contains more than one Table at a time. We can set up Data Relations between these tables within the DataSet. The DataAdapter Object allows us to fill DataTables in a DataSet. We can use Fill method of the DataAdapter for populating data in a Dataset. The DataSet can be filled either from a data source or dynamically. A DataSet can be saved to an XML file and then loaded back into memory very easily. A DataSet can read and write data and schema as XML documents. The data and schema can then be transported across HTTP and used by any application, on any platform that is XML-enabled.

Dataset with Sql Server

The DataSet contains the copy of the data requested through the SQL statement. The DataSet is a memory-resident representation of data that provides a consistent relational programming model regardless of the data source.

We can use Dataset in combination with SqlDataAdapter Class. Build and fill each DataTable in a DataSet with data from a data source using a DataAdapter. The SqlDataAdapter object allows us to populate Data Tables in a DataSet.

Example

string strConnection = "Server = abc\\SQLEXPRESs; Database=Employee; Trusted_Connection=True";
SqlConnection con = new SqlConnection(strConnection);
con.Open();
SqlDataAdapter da = new SqlDataAdapter("select * from employee", con);
DataSet ds = new DataSet();
da.Fill(ds, "Employee");

Tables in a Dataset

The DataSet contains DataTableCollection and their DataRelationCollection. The DataTableCollection contains zero or more DataTable objects. The Dataset may comprise data for one or more members, corresponding to the number of rows. The SqlDataAdapter Object allows us to populate DataTables in a DataSet. Build and fill each DataTable in a DataSet with data from a data source using a DataAdapter.

Example

DataTable dt = ds.Tables["Employee"];

Dataset rows count

The DataSet Object contains copy of the data requested through the SQL statement. The DataSet consists of DataTableCollection and their DataRelationCollection. The DataTableCollection contains zero or more DataTable objects. A DataSet represents a complete set of data.

The Dataset may comprise data for one or more members, corresponding to the number of rows. The DataRow Class represents the actual data contained in a table. We use the DataRow and its properties and methods to retrieve, evaluate, and manipulate the data in a table.

Example

MessageBox.Show("Number of row(s) - " + ds.Tables[0].Rows.Count);

How to find Column Definition

The data inside Table is in the form of Rows and Columns. The DataRow class represents the actual data contained in a table. We use the DataRow and its properties and methods to retrieve, evaluate, and manipulate the data in a table. In some situations we have to find the column headers in a DataTable. There is a ColumnsCollection Object in the Datatable hold the column Definitions.

Example

foreach (DataColumn column in dt.Columns)
{
MessageBox.Show(column.ColumnName);
}