Lição 3: Recuperando um lista de campos para a definição de relatório

Como cada definição de relatório deve ter uma lista de campos que representam os dados no relatório, você deve gerar uma lista de campos com base na sua consulta.

Para gerar uma lista de campos

  • Substitua o código para o método GenerateFieldsList () em seu projeto pelo seguinte código:
Public Sub GenerateFieldsList()
   Dim command As SqlCommand
   Dim reader As SqlDataReader
   
   ' Executing a query to retrieve a fields list for the report
   command = m_connection.CreateCommand()
   m_commandText = "SELECT Person.CountryRegion.Name AS CountryName, Person.StateProvince.Name AS StateProvince " + "FROM Person.StateProvince " + "INNER JOIN Person.CountryRegion ON Person.StateProvince.CountryRegionCode = Person.CountryRegion.CountryRegionCode " + "ORDER BY Person.CountryRegion.Name"
   command.CommandText = m_commandText
   
   ' Execute and create a reader for the current command
   reader = command.ExecuteReader(CommandBehavior.SchemaOnly)
   
   ' For each field in the resultset, add the name to an array list
   m_fields = New ArrayList()
   Dim i As Integer
   For i = 0 To reader.FieldCount - 1
      m_fields.Add(reader.GetName(i))
   Next i
End Sub 'GenerateFieldsList
public void GenerateFieldsList()
{
   SqlCommand command;
   SqlDataReader reader;

   // Executing a query to retrieve a fields list for the report
   command = m_connection.CreateCommand();
   m_commandText = 
      "SELECT Person.CountryRegion.Name AS CountryName, Person.StateProvince.Name AS StateProvince " +
      "FROM Person.StateProvince " +
      "INNER JOIN Person.CountryRegion ON Person.StateProvince.CountryRegionCode = Person.CountryRegion.CountryRegionCode " +
      "ORDER BY Person.CountryRegion.Name";
   command.CommandText = m_commandText;
   
   // Execute and create a reader for the current command
   reader = command.ExecuteReader(CommandBehavior.SchemaOnly);
   
   // For each field in the resultset, add the name to an array list
   m_fields = new ArrayList();
   for (int i = 0; i <= reader.FieldCount - 1; i++)
   {
      m_fields.Add(reader.GetName(i));
   }
}