ULDataReader class

Represents a read-only bi-directional cursor in an UltraLite database.

Visual Basic syntax

Public Class ULDataReader
    Inherits System.Data.Common.DbDataReader
    Implements System.ComponentModel.IListSource

C# syntax

public class ULDataReader : 
    System.Data.Common.DbDataReader, 
    System.ComponentModel.IListSource

Members

All members of ULDataReader class, including all inherited members.

Name	Description
Close method	Closes the cursor.
Dispose method (Inherited from System.Data.Common.DbDataReader)	Releases all resources used by the current instance of the System.Data.Common.DbDataReader class.
GetBoolean method	Returns the value for the specified column as a System.Boolean.
GetByte method	Returns the value for the specified column as an unsigned 8-bit value (System.Byte).
GetBytes method	UL Ext: Returns the value for the specified column as an array of System.Bytes.
GetChar method	This method is not supported in UltraLite.NET.
GetChars method	Copies a subset of the value for the specified ULDbType.LongVarchar column, beginning at the specified offset, to the specified offset of the destination System.Char array.
GetData method (Inherited from System.Data.Common.DbDataReader)	Returns a System.Data.Common.DbDataReader object for the requested column ordinal.
GetDataTypeName method	Returns the name of the specified column's provider data type.
GetDateTime method	Returns the value for the specified column as a System.DateTime with millisecond accuracy.
GetDbDataReader method (Inherited from System.Data.Common.DbDataReader)	Returns a System.Data.Common.DbDataReader object for the requested column ordinal that can be overridden with a provider-specific implementation.
GetDecimal method	Returns the value for the specified column as a System.Decimal.
GetDouble method	Returns the value for the specified column as a System.Double.
GetEnumerator method	Returns an System.Collections.IEnumerator that iterates through the ULDataReader.
GetFieldType method	Returns the System.Type most appropriate for the specified column.
GetFloat method	Returns the value for the specified column as a System.Single.
GetGuid method	Returns the value for the specified column as a UUID (System.Guid).
GetInt16 method	Returns the value for the specified column as a System.Int16.
GetInt32 method	Returns the value for the specified column as an Int32.
GetInt64 method	Returns the value for the specified column as an Int64.
GetName method	Returns the name of the specified column.
GetOrdinal method	Returns the column ID of the named column.
GetProviderSpecificFieldType method (Inherited from System.Data.Common.DbDataReader)	Returns the provider-specific field type of the specified column.
GetProviderSpecificValue method (Inherited from System.Data.Common.DbDataReader)	Gets the value of the specified column as an instance of System.Object.
GetProviderSpecificValues method (Inherited from System.Data.Common.DbDataReader)	Gets all provider-specific attribute columns in the collection for the current row.
GetRowCount method	UL Ext: Returns the number of rows in the cursor, within threshold.
GetSchemaTable method	Returns a System.Data.DataTable that describes the column metadata of the ULDataReader.
GetString method	Returns the value for the specified column as a System.String.
GetTimeSpan method	Returns the value for the specified column as a System.TimeSpan with millisecond accuracy.
GetUInt16 method	Returns the value for the specified column as a System.UInt16.
GetUInt32 method	Returns the value for the specified column as a UInt32.
GetUInt64 method	Returns the value for the specified column as a System.UInt64.
GetValue method	Returns the value of the specified column in its native format.
GetValues method	Returns all the column values for the current row.
IsDBNull method	Checks whether the value from the specified column is NULL.
MoveAfterLast method	UL Ext: Positions the cursor to after the last row of the cursor.
MoveBeforeFirst method	UL Ext: Positions the cursor to before the first row of the cursor.
MoveFirst method	UL Ext: Positions the cursor to the first row of the cursor.
MoveLast method	UL Ext: Positions the cursor to the last row of the cursor.
MoveNext method	UL Ext: Positions the cursor to the next row or after the last row if the cursor was already on the last row.
MovePrevious method	UL Ext: Positions the cursor to the previous row or before the first row.
MoveRelative method	UL Ext: Positions the cursor relative to the current row.
NextResult method	Advances the ULDataReader to the next result when reading the results of batch SQL statements.
Read method	Positions the cursor to the next row, or after the last row if the cursor was already on the last row.
Depth property	Returns the depth of nesting for the current row.
FieldCount property	Returns the number of columns in the cursor.
HasRows property	Checks whether the ULDataReader has one or more rows.
IsBOF property	UL Ext: Checks whether the current row position is before the first row.
IsClosed property	Checks whether the cursor is currently open.
IsEOF property	UL Ext: Checks whether the current row position is after the last row.
RecordsAffected property	Returns the number of rows changed, inserted, or deleted by execution of the SQL statement.
RowCount property	UL Ext: Returns the number of rows in the cursor.
Schema property	UL Ext: Holds the schema of this cursor.
this property	Returns the value of the specified column in its native format.
VisibleFieldCount property (Inherited from System.Data.Common.DbDataReader)	Gets the number of fields in the System.Data.Common.DbDataReader that are not hidden.

Remarks

Cursors are sets of rows from either a table or the result set from a query.

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", conn _
)
Dim reader As ULDataReader = cmd.ExecuteReader()

The following code is the C# language equivalent:

// C#
ULCommand cmd = new ULCommand(
    "SELECT emp_id FROM employee", 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.