Hi First you have to define the Method in interface like this
[OperationContract]
DataSet GetEmployees();
This method will return dataset.
Then go to Web.config file and declare your connection
<connectionstrings>
<add name="FAST" connectionstring="Server=localhost;User id=Ashad-PC\Ashad;Password=;Initial Catalog=FAST_PROD;Integrated Security=SSPI" />
</connectionstrings>
Then give the implementation for this method in your class
public DataSet GetEmployees()
{
SqlConnection con = new SqlConnection(WebConfigurationManager.ConnectionStrings["FAST"].ConnectionString);
SqlCommand cmd = new SqlCommand("select * from Employee", con);
SqlDataAdapter da = new SqlDataAdapter(cmd);
DataSet ds = new DataSet();
da.Fill(ds);
return ds;
}
Create a client application,create the proxy of your wcf service and bind the dataset to dropdownlist of gridview or whatever you want.