Represents a read-only bi-directional cursor in an UltraLite database. Cursors are sets of rows from either a table or the result set from a query.

Syntax

Visual Basic
Public Class ULDataReader
  Inherits DbDataReader

C#
public class ULDataReader: DbDataReader

Remarks

There is no constructor for ULDataReader. To get a ULDataReader object, execute a ULCommand:

' Visual Basic
Dim cmd As ULCommand = new ULCommand( _
    "SELECT emp_id FROM employee FOR READ ONLY", conn _
  )
Dim reader As ULDataReader = cmd.ExecuteReader()

// C#
ULCommand cmd = new ULCommand(
    "SELECT emp_id FROM employee FOR READ ONLY", conn
  );
ULDataReader reader = cmd.ExecuteReader();

UL Ext.: The ADO.NET standard only requires forward-only motion through the result set, but ULDataReader is bi-directional. ULDataReader's Move methods provide you with full flexibility when moving through results.

ULDataReader is a read-only result set. If you need a more flexible object to manipulate results, use a ULCommand.ExecuteResultSet(), ULCommand.ExecuteTable(), or a ULDataAdapter. ULDataReader retrieves rows as needed, whereas ULDataAdapter must retrieve all rows of a result set before you can carry out any action on the object. For large result sets, this difference gives the ULDataReader a much faster response time.

UL Ext.: All columns of a ULDataReader may be retrieved using GetString.

Inherits: System.Data.Common.DbDataReader

Implements: System.Data.IDataReader, System.Data.IDataRecord, System.IDisposable, System.ComponentModel.IListSource

See also

• ULDataReader members
• ULCommand class
• ExecuteResultSet() method
• ExecuteTable() method
• ULDataAdapter class
• GetString method
•  DbDataReader
•  IDataReader
•  IDataRecord
•  IDisposable
•  IListSource