OracleDataReader Class

OracleDataReader Class

 

Provides a way of reading a forward-only stream of data rows from a data source. This class cannot be inherited.

Namespace:   System.Data.OracleClient
Assembly:  System.Data.OracleClient (in System.Data.OracleClient.dll)

System.Object
  System.MarshalByRefObject
    System.Data.Common.DbDataReader
      System.Data.OracleClient.OracleDataReader

Public NotInheritable Class OracleDataReader
	Inherits DbDataReader

NameDescription
System_CAPS_pubpropertyDepth

Gets a value indicating the depth of nesting for the current row.(Overrides DbDataReader.Depth.)

System_CAPS_pubpropertyFieldCount

Gets the number of columns in the current row.(Overrides DbDataReader.FieldCount.)

System_CAPS_pubpropertyHasRows

Gets a value indicating whether the OracleDataReader contains one or more rows.(Overrides DbDataReader.HasRows.)

System_CAPS_pubpropertyIsClosed

Indicates whether the OracleDataReader is closed.(Overrides DbDataReader.IsClosed.)

System_CAPS_pubpropertyItem(Int32)

Gets the value of the specified column in its native format given the column ordinal.(Overrides DbDataReader.Item(Int32).)

System_CAPS_pubpropertyItem(String)

Gets the value of the specified column in its native format given the column name.(Overrides DbDataReader.Item(String).)

System_CAPS_pubpropertyRecordsAffected

Gets the number of rows changed, inserted, or deleted by execution of the SQL statement.(Overrides DbDataReader.RecordsAffected.)

System_CAPS_pubpropertyVisibleFieldCount

Gets the number of fields in the DbDataReader that are not hidden.(Inherited from DbDataReader.)

NameDescription
System_CAPS_pubmethodClose()

Closes the OracleDataReader object.(Overrides DbDataReader.Close().)

System_CAPS_pubmethodCreateObjRef(Type)

Creates an object that contains all the relevant information required to generate a proxy used to communicate with a remote object.(Inherited from MarshalByRefObject.)

System_CAPS_pubmethodDispose()

Releases all resources used by the current instance of the DbDataReader class.(Inherited from DbDataReader.)

System_CAPS_pubmethodEquals(Object)

Determines whether the specified object is equal to the current object.(Inherited from Object.)

System_CAPS_pubmethodGetBoolean(Int32)

Gets the value of the specified column as a Boolean.(Overrides DbDataReader.GetBoolean(Int32).)

System_CAPS_pubmethodGetByte(Int32)

Gets the value of the specified column as a byte.(Overrides DbDataReader.GetByte(Int32).)

System_CAPS_pubmethodGetBytes(Int32, Int64, Byte(), Int32, Int32)

Reads a stream of bytes from the specified column offset into the buffer as an array, starting at the given buffer offset.(Overrides DbDataReader.GetBytes(Int32, Int64, Byte(), Int32, Int32).)

System_CAPS_pubmethodGetChar(Int32)

Gets the value of the specified column as a character.(Overrides DbDataReader.GetChar(Int32).)

System_CAPS_pubmethodGetChars(Int32, Int64, Char(), Int32, Int32)

Reads a stream of characters from the specified column offset into the buffer as an array, starting at the given buffer offset.(Overrides DbDataReader.GetChars(Int32, Int64, Char(), Int32, Int32).)

System_CAPS_pubmethodGetData(Int32)

Returns a DbDataReader object for the requested column ordinal.(Inherited from DbDataReader.)

System_CAPS_pubmethodGetDataTypeName(Int32)

Gets the name of the source data type.(Overrides DbDataReader.GetDataTypeName(Int32).)

System_CAPS_pubmethodGetDateTime(Int32)

Gets the value of the specified column as a DateTime object.(Overrides DbDataReader.GetDateTime(Int32).)

System_CAPS_pubmethodGetDecimal(Int32)

Gets the value of the specified column as a Decimal object.(Overrides DbDataReader.GetDecimal(Int32).)

System_CAPS_pubmethodGetDouble(Int32)

Gets the value of the specified column as a double-precision floating point number.(Overrides DbDataReader.GetDouble(Int32).)

System_CAPS_pubmethodGetEnumerator()

Returns an IEnumerator that can be used to iterate through the rows in the data reader.(Overrides DbDataReader.GetEnumerator().)

System_CAPS_pubmethodGetFieldType(Int32)

Gets the Type that is the data type of the object.(Overrides DbDataReader.GetFieldType(Int32).)

System_CAPS_pubmethodGetFieldValue(Of T)(Int32)

Synchronously gets the value of the specified column as a type.(Inherited from DbDataReader.)

System_CAPS_pubmethodGetFieldValueAsync(Of T)(Int32)

Asynchronously gets the value of the specified column as a type.(Inherited from DbDataReader.)

System_CAPS_pubmethodGetFieldValueAsync(Of T)(Int32, CancellationToken)

Asynchronously gets the value of the specified column as a type.(Inherited from DbDataReader.)

System_CAPS_pubmethodGetFloat(Int32)

Gets the value of the specified column as a single-precision floating-point number.(Overrides DbDataReader.GetFloat(Int32).)

System_CAPS_pubmethodGetGuid(Int32)

Gets the value of the specified column as a globally-unique identifier (GUID).(Overrides DbDataReader.GetGuid(Int32).)

System_CAPS_pubmethodGetHashCode()

Serves as the default hash function. (Inherited from Object.)

System_CAPS_pubmethodGetInt16(Int32)

Gets the value of the specified column as a 16-bit signed integer.(Overrides DbDataReader.GetInt16(Int32).)

System_CAPS_pubmethodGetInt32(Int32)

Gets the value of the specified column as a 32-bit signed integer.(Overrides DbDataReader.GetInt32(Int32).)

System_CAPS_pubmethodGetInt64(Int32)

Gets the value of the specified column as a 64-bit signed integer.(Overrides DbDataReader.GetInt64(Int32).)

System_CAPS_pubmethodGetLifetimeService()

Retrieves the current lifetime service object that controls the lifetime policy for this instance.(Inherited from MarshalByRefObject.)

System_CAPS_pubmethodGetName(Int32)

Gets the name of the specified column.(Overrides DbDataReader.GetName(Int32).)

System_CAPS_pubmethodGetOracleBFile(Int32)

Gets the value of the specified column as an OracleBFile object.

System_CAPS_pubmethodGetOracleBinary(Int32)

Gets the value of the specified column as an OracleBinary object.

System_CAPS_pubmethodGetOracleDateTime(Int32)

Gets the value of the specified column as an OracleDateTime object.

System_CAPS_pubmethodGetOracleLob(Int32)

Gets the value of the specified column as an OracleLob object.

System_CAPS_pubmethodGetOracleMonthSpan(Int32)

Gets the value of the specified column as an OracleMonthSpan object.

System_CAPS_pubmethodGetOracleNumber(Int32)

Gets the value of the specified column as an OracleNumber object.

System_CAPS_pubmethodGetOracleString(Int32)

Gets the value of the specified column as an OracleString object.

System_CAPS_pubmethodGetOracleTimeSpan(Int32)

Gets the value of the specified column as an OracleTimeSpan object.

System_CAPS_pubmethodGetOracleValue(Int32)

Gets the value of the column at the specified ordinal in its Oracle format.

System_CAPS_pubmethodGetOracleValues(Object())

Gets all the attribute columns in the current row in Oracle format.

System_CAPS_pubmethodGetOrdinal(String)

Gets the column ordinal, given the name of the column.(Overrides DbDataReader.GetOrdinal(String).)

System_CAPS_pubmethodGetProviderSpecificFieldType(Int32)

Gets an Object that is a representation of the underlying provider specific field type.(Overrides DbDataReader.GetProviderSpecificFieldType(Int32).)

System_CAPS_pubmethodGetProviderSpecificValue(Int32)

Gets an Object that is a representation of the underlying provider specific field type.(Overrides DbDataReader.GetProviderSpecificValue(Int32).)

System_CAPS_pubmethodGetProviderSpecificValues(Object())

Gets an array of objects that are a representation of the underlying provider specific values.(Overrides DbDataReader.GetProviderSpecificValues(Object()).)

System_CAPS_pubmethodGetSchemaTable()

Returns a DataTable that describes the column metadata of the OracleDataReader.(Overrides DbDataReader.GetSchemaTable().)

System_CAPS_pubmethodGetStream(Int32)

Retrieves data as a Stream.(Inherited from DbDataReader.)

System_CAPS_pubmethodGetString(Int32)

Gets the value of the specified column as a string.(Overrides DbDataReader.GetString(Int32).)

System_CAPS_pubmethodGetTextReader(Int32)

Retrieves data as a TextReader.(Inherited from DbDataReader.)

System_CAPS_pubmethodGetTimeSpan(Int32)

Gets the value of the specified column as a System.TimeSpan.

System_CAPS_pubmethodGetType()

Gets the Type of the current instance.(Inherited from Object.)

System_CAPS_pubmethodGetValue(Int32)

Gets the value of the column at the specified ordinal in its native format.(Overrides DbDataReader.GetValue(Int32).)

System_CAPS_pubmethodGetValues(Object())

Populates an array of objects with the column values of the current row.(Overrides DbDataReader.GetValues(Object()).)

System_CAPS_pubmethodInitializeLifetimeService()

Obtains a lifetime service object to control the lifetime policy for this instance.(Inherited from MarshalByRefObject.)

System_CAPS_pubmethodIsDBNull(Int32)

Gets a value indicating whether the column contains non-existent or missing values.(Overrides DbDataReader.IsDBNull(Int32).)

System_CAPS_pubmethodIsDBNullAsync(Int32)

An asynchronous version of IsDBNull, which gets a value that indicates whether the column contains non-existent or missing values.(Inherited from DbDataReader.)

System_CAPS_pubmethodIsDBNullAsync(Int32, CancellationToken)

An asynchronous version of IsDBNull, which gets a value that indicates whether the column contains non-existent or missing values. Optionally, sends a notification that operations should be cancelled.(Inherited from DbDataReader.)

System_CAPS_pubmethodNextResult()

Advances the OracleDataReader to the next result (Overrides DbDataReader.NextResult().)

System_CAPS_pubmethodNextResultAsync()

An asynchronous version of NextResult, which advances the reader to the next result when reading the results of a batch of statements.

Invokes NextResultAsync with CancellationToken.None.(Inherited from DbDataReader.)

System_CAPS_pubmethodNextResultAsync(CancellationToken)

This is the asynchronous version of NextResult. Providers should override with an appropriate implementation. The cancellationToken may optionally be ignored.

The default implementation invokes the synchronous NextResult method and returns a completed task, blocking the calling thread. The default implementation will return a cancelled task if passed an already cancelled cancellationToken. Exceptions thrown by NextResult will be communicated via the returned Task Exception property.

Other methods and properties of the DbDataReader object should not be invoked while the returned Task is not yet completed.(Inherited from DbDataReader.)

System_CAPS_pubmethodRead()

Advances the OracleDataReader to the next record.(Overrides DbDataReader.Read().)

System_CAPS_pubmethodReadAsync()

An asynchronous version of Read, which advances the reader to the next record in a result set. This method invokes ReadAsync with CancellationToken.None.(Inherited from DbDataReader.)

System_CAPS_pubmethodReadAsync(CancellationToken)

This is the asynchronous version of Read. Providers should override with an appropriate implementation. The cancellationToken may optionally be ignored.

The default implementation invokes the synchronous Read method and returns a completed task, blocking the calling thread. The default implementation will return a cancelled task if passed an already cancelled cancellationToken. Exceptions thrown by Read will be communicated via the returned Task Exception property.

Do not invoke other methods and properties of the DbDataReader object until the returned Task is complete.(Inherited from DbDataReader.)

System_CAPS_pubmethodToString()

Returns a string that represents the current object.(Inherited from Object.)

NameDescription
System_CAPS_pubinterfaceSystem_CAPS_privmethodIDataRecord.GetData(Int32)

For a description of this member, see IDataRecord.GetData.(Inherited from DbDataReader.)

NameDescription
System_CAPS_pubmethodAsParallel()

Overloaded. Enables parallelization of a query.(Defined by ParallelEnumerable.)

System_CAPS_pubmethodAsQueryable()

Overloaded. Converts an IEnumerable to an IQueryable.(Defined by Queryable.)

System_CAPS_pubmethodCast(Of TResult)()

Casts the elements of an IEnumerable to the specified type.(Defined by Enumerable.)

System_CAPS_pubmethodOfType(Of TResult)()

Filters the elements of an IEnumerable based on a specified type.(Defined by Enumerable.)

To create an OracleDataReader, you must call the ExecuteReader method of the OracleCommand object, rather than directly using a constructor.

Changes made to a resultset by another process or thread while data is being read may be visible to the user of the OracleDataReader.

IsClosed and RecordsAffected are the only properties that you can call after the OracleDataReader is closed. In some cases, you must call Close before you can call RecordsAffected.

More than one OracleDataReader can be open at any given time.

The following two Visual Basic examples demonstrate how to use an OracleDataReader to retrieve an Oracle REF CURSOR. These examples use tables that are defined in the Oracle Scott/Tiger schema, and require the following PL/SQL package and package body. You must create these on your server to use the examples.

Create the following Oracle package on the Oracle server.

CREATE OR REPLACE PACKAGE CURSPKG AS 
   TYPE T_CURSOR IS REF CURSOR; 
   PROCEDURE OPEN_ONE_CURSOR (N_EMPNO IN NUMBER, 
      IO_CURSOR IN OUT T_CURSOR); 
   PROCEDURE OPEN_TWO_CURSORS (EMPCURSOR OUT T_CURSOR, 
      DEPTCURSOR OUT T_CURSOR);
END CURSPKG;
/

Create the following Oracle package body on the Oracle server.


CREATE OR REPLACE PACKAGE BODY CURSPKG AS 
    PROCEDURE OPEN_ONE_CURSOR (N_EMPNO IN NUMBER, 
                               IO_CURSOR OUT T_CURSOR) 
    IS 
        V_CURSOR T_CURSOR; 
    BEGIN 
        IF N_EMPNO <> 0 THEN 
             OPEN V_CURSOR FOR 
             SELECT EMP.EMPNO, EMP.ENAME, DEPT.DEPTNO, DEPT.DNAME 
                  FROM EMP, DEPT 
                  WHERE EMP.DEPTNO = DEPT.DEPTNO 
                        AND EMP.EMPNO = N_EMPNO; 
        ELSE 
             OPEN V_CURSOR FOR 
             SELECT EMP.EMPNO, EMP.ENAME, DEPT.DEPTNO, DEPT.DNAME 
                  FROM EMP, DEPT 
                  WHERE EMP.DEPTNO = DEPT.DEPTNO; 
        END IF; 
        IO_CURSOR := V_CURSOR; 
    END OPEN_ONE_CURSOR; 
    PROCEDURE OPEN_TWO_CURSORS (EMPCURSOR OUT T_CURSOR, 
                                DEPTCURSOR OUT T_CURSOR) 
    IS 
        V_CURSOR1 T_CURSOR; 
        V_CURSOR2 T_CURSOR; 
    BEGIN 
        OPEN V_CURSOR1 FOR SELECT * FROM EMP; 
        OPEN V_CURSOR2 FOR SELECT * FROM DEPT; 
        EMPCURSOR  := V_CURSOR1; 
        DEPTCURSOR := V_CURSOR2; 
    END OPEN_TWO_CURSORS; 
END CURSPKG;
/

This Visual Basic example executes a PL/SQL stored procedure that returns a REF CURSOR parameter, and reads the value as an OracleDataReader.

Private Sub ReadOracleData(ByVal connectionString As String)
   Dim connection As New OracleConnection(connectionString)
   Dim command As New OracleCommand()
   Dim reader As OracleDataReader

   connection.Open()
   command.Connection = connection
   command.CommandText = "CURSPKG.OPEN_ONE_CURSOR"
   command.CommandType = CommandType.StoredProcedure
   command.Parameters.Add(New OracleParameter("N_EMPNO", OracleType.Number)).Value = 7369
   command.Parameters.Add(New OracleParameter("IO_CURSOR", OracleType.Cursor)).Direction = ParameterDirection.Output

   reader = command.ExecuteReader()
   While (reader.Read())
      ' Do something with the values.
   End While
   reader.Close()
   connection.Close()
End Sub

This Visual Basic example executes a PL/SQL stored procedure that returns two REF CURSOR parameters, and reads the values using an OracleDataReader.

Private Sub ReadOracleData(ByVal connectionString As String)
   Dim dataSet As New DataSet()
   Dim connection As New OracleConnection(connectionString)
   Dim command As New OracleCommand()
   Dim reader As OracleDataReader

   connection.Open()
   command.Connection = connection
   command.CommandText = "CURSPKG.OPEN_TWO_CURSORS"
   command.CommandType = CommandType.StoredProcedure
   command.Parameters.Add(New OracleParameter("EMPCURSOR", OracleType.Cursor)).Direction = ParameterDirection.Output
   command.Parameters.Add(New OracleParameter("DEPTCURSOR", OracleType.Cursor)).Direction = ParameterDirection.Output

   reader = command.ExecuteReader(CommandBehavior.CloseConnection)
   While (reader.Read())
      ' Do something with the values.
   End While
   reader.NextResult()
   While (reader.Read())
        ' Do something with the values.
   End While
   reader.Close()
   connection.Close()
 End Sub

This C# example creates an Oracle table and loads it with data. You must run this example prior to running the subsequent example, which demonstrates using an OracleDataReader to access the data using OracleType structures.

public void Setup(string connectionString)
{
   OracleConnection connection = new OracleConnection(connectionString);
   try
   {
      connection.Open();
      OracleCommand command = connection.CreateCommand();
      command.CommandText ="CREATE TABLE OracleTypesTable (MyVarchar2 varchar2(3000),MyNumber number(28,4) PRIMARY KEY,MyDate date, MyRaw raw(255))";
      command.ExecuteNonQuery();
      command.CommandText ="INSERT INTO OracleTypesTable VALUES ('test', 2, to_date('2000-01-11 12:54:01','yyyy-mm-dd hh24:mi:ss'), '0001020304')";
      command.ExecuteNonQuery();
      command.CommandText="SELECT * FROM OracleTypesTable";
   }
   catch(Exception)
   {
   }
   finally
   {
      connection.Close();
   }
}

This C# example uses an OracleDataReader to access data, and uses several OracleType structures to display the data.

public void ReadOracleTypesExample(string connectionString)
{
   OracleConnection connection = new OracleConnection(connectionString);
   connection.Open();
   OracleCommand command = connection.CreateCommand();
   try
   {
      command.CommandText = "SELECT * FROM OracleTypesTable";
      OracleDataReader reader = command.ExecuteReader();
      reader.Read();
      //Using the Oracle specific getters for each type is faster than
      //using GetOracleValue.
      //First column, MyVarchar2, is a VARCHAR2 data type in Oracle Server
      //and maps to OracleString.
      OracleString oraclestring1 = reader.GetOracleString(0);
      Console.WriteLine("OracleString " + oraclestring1.ToString());

      //Second column, MyNumber, is a NUMBER data type in Oracle Server
      //and maps to OracleNumber.
      OracleNumber oraclenumber1 = reader.GetOracleNumber(1);
      Console.WriteLine("OracleNumber " + oraclenumber1.ToString());

      //Third column, MyDate, is a DATA data type in Oracle Server
      //and maps to OracleDateTime.
      OracleDateTime oracledatetime1 = reader.GetOracleDateTime(2);
      Console.WriteLine("OracleDateTime " + oracledatetime1.ToString());

      //Fourth column, MyRaw, is a RAW data type in Oracle Server and
      //maps to OracleBinary.
      OracleBinary oraclebinary1 = reader.GetOracleBinary(3);

      //Calling value on a null OracleBinary throws
      //OracleNullValueException; therefore, check for a null value.
      if (oraclebinary1.IsNull==false)
      {
         foreach(byte b in oraclebinary1.Value)
         {
            Console.WriteLine("byte " + b.ToString());
         }
      }
      reader.Close();
   }
   catch(Exception e)
   {
      Console.WriteLine(e.ToString());
   }
   finally
   {
      connection.Close();
   }
}

The following example creates an OracleConnection, an OracleCommand, and an OracleDataReader. The example reads through the data, writing it out to the console. Finally, the example closes the OracleDataReader, then the OracleConnection.

Public Sub ReadData(ByVal connectionString As String)
    Dim queryString As String = "SELECT EmpNo, EName FROM Emp"
    Using connection As New OracleConnection(connectionString)
        Dim command As New OracleCommand(queryString, connection)
        connection.Open()
        Using reader As OracleDataReader = command.ExecuteReader()
            ' Always call Read before accessing data.
            While reader.Read()
                Console.WriteLine(reader.GetInt32(0).ToString() + ", " _
                   + reader.GetString(1))
            End While
        End Using
    End Using
End Sub

.NET Framework
Available since 1.1

Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.

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