OracleDataReader Class
Provides a way of reading a forward-only stream of data rows from a data source. This class cannot be inherited.
System::MarshalByRefObject
System.Data.Common::DbDataReader
System.Data.OracleClient::OracleDataReader
Assembly: System.Data.OracleClient (in System.Data.OracleClient.dll)
The OracleDataReader type exposes the following members.
| Name | Description | |
|---|---|---|
![]() | Depth | Gets a value indicating the depth of nesting for the current row. (Overrides DbDataReader::Depth.) |
![]() | FieldCount | Gets the number of columns in the current row. (Overrides DbDataReader::FieldCount.) |
![]() | HasRows | Gets a value indicating whether the OracleDataReader contains one or more rows. (Overrides DbDataReader::HasRows.) |
![]() | IsClosed | Indicates whether the OracleDataReader is closed. (Overrides DbDataReader::IsClosed.) |
![]() | Item[Int32] | Gets the value of the specified column in its native format given the column ordinal. (Overrides DbDataReader::Item[Int32].) |
![]() | Item[String] | Gets the value of the specified column in its native format given the column name. (Overrides DbDataReader::Item[String].) |
![]() | RecordsAffected | Gets the number of rows changed, inserted, or deleted by execution of the SQL statement. (Overrides DbDataReader::RecordsAffected.) |
![]() | VisibleFieldCount | Gets the number of fields in the DbDataReader that are not hidden. (Inherited from DbDataReader.) |
| Name | Description | |
|---|---|---|
![]() | Close | Closes the OracleDataReader object. (Overrides DbDataReader::Close().) |
![]() | CreateObjRef | Creates an object that contains all the relevant information required to generate a proxy used to communicate with a remote object. (Inherited from MarshalByRefObject.) |
![]() | Dispose() | Releases all resources used by the current instance of the DbDataReader class. (Inherited from DbDataReader.) |
![]() | Dispose(Boolean) | Releases the managed resources used by the DbDataReader and optionally releases the unmanaged resources. (Inherited from DbDataReader.) |
![]() | Equals(Object) | Determines whether the specified Object is equal to the current Object. (Inherited from Object.) |
![]() | Finalize | Allows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection. (Inherited from Object.) |
![]() | GetBoolean | Gets the value of the specified column as a Boolean. (Overrides DbDataReader::GetBoolean(Int32).) |
![]() | GetByte | Gets the value of the specified column as a byte. (Overrides DbDataReader::GetByte(Int32).) |
![]() | GetBytes | 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, array<Byte>, Int32, Int32).) |
![]() | GetChar | Gets the value of the specified column as a character. (Overrides DbDataReader::GetChar(Int32).) |
![]() | GetChars | 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, array<Char>, Int32, Int32).) |
![]() | GetData | Returns a DbDataReader object for the requested column ordinal. (Inherited from DbDataReader.) |
![]() | GetDataTypeName | Gets the name of the source data type. (Overrides DbDataReader::GetDataTypeName(Int32).) |
![]() | GetDateTime | Gets the value of the specified column as a DateTime object. (Overrides DbDataReader::GetDateTime(Int32).) |
![]() | GetDbDataReader | Returns a DbDataReader object for the requested column ordinal that can be overridden with a provider-specific implementation. (Inherited from DbDataReader.) |
![]() | GetDecimal | Gets the value of the specified column as a Decimal object. (Overrides DbDataReader::GetDecimal(Int32).) |
![]() | GetDouble | Gets the value of the specified column as a double-precision floating point number. (Overrides DbDataReader::GetDouble(Int32).) |
![]() | GetEnumerator | Returns an IEnumerator that can be used to iterate through the rows in the data reader. (Overrides DbDataReader::GetEnumerator().) |
![]() | GetFieldType | Gets the Type that is the data type of the object. (Overrides DbDataReader::GetFieldType(Int32).) |
![]() | GetFloat | Gets the value of the specified column as a single-precision floating-point number. (Overrides DbDataReader::GetFloat(Int32).) |
![]() | GetGuid | Gets the value of the specified column as a globally-unique identifier (GUID). (Overrides DbDataReader::GetGuid(Int32).) |
![]() | GetHashCode | Serves as a hash function for a particular type. (Inherited from Object.) |
![]() | GetInt16 | Gets the value of the specified column as a 16-bit signed integer. (Overrides DbDataReader::GetInt16(Int32).) |
![]() | GetInt32 | Gets the value of the specified column as a 32-bit signed integer. (Overrides DbDataReader::GetInt32(Int32).) |
![]() | GetInt64 | Gets the value of the specified column as a 64-bit signed integer. (Overrides DbDataReader::GetInt64(Int32).) |
![]() | GetLifetimeService | Retrieves the current lifetime service object that controls the lifetime policy for this instance. (Inherited from MarshalByRefObject.) |
![]() | GetName | Gets the name of the specified column. (Overrides DbDataReader::GetName(Int32).) |
![]() | GetOracleBFile | Gets the value of the specified column as an OracleBFile object. |
![]() | GetOracleBinary | Gets the value of the specified column as an OracleBinary object. |
![]() | GetOracleDateTime | Gets the value of the specified column as an OracleDateTime object. |
![]() | GetOracleLob | Gets the value of the specified column as an OracleLob object. |
![]() | GetOracleMonthSpan | Gets the value of the specified column as an OracleMonthSpan object. |
![]() | GetOracleNumber | Gets the value of the specified column as an OracleNumber object. |
![]() | GetOracleString | Gets the value of the specified column as an OracleString object. |
![]() | GetOracleTimeSpan | Gets the value of the specified column as an OracleTimeSpan object. |
![]() | GetOracleValue | Gets the value of the column at the specified ordinal in its Oracle format. |
![]() | GetOracleValues | Gets all the attribute columns in the current row in Oracle format. |
![]() | GetOrdinal | Gets the column ordinal, given the name of the column. (Overrides DbDataReader::GetOrdinal(String).) |
![]() | GetProviderSpecificFieldType | Gets an Object that is a representation of the underlying provider specific field type. (Overrides DbDataReader::GetProviderSpecificFieldType(Int32).) |
![]() | GetProviderSpecificValue | Gets an Object that is a representation of the underlying provider specific field type. (Overrides DbDataReader::GetProviderSpecificValue(Int32).) |
![]() | GetProviderSpecificValues | Gets an array of objects that are a representation of the underlying provider specific values. (Overrides DbDataReader::GetProviderSpecificValues(array<Object>).) |
![]() | GetSchemaTable | Returns a DataTable that describes the column metadata of the OracleDataReader. (Overrides DbDataReader::GetSchemaTable().) |
![]() | GetString | Gets the value of the specified column as a string. (Overrides DbDataReader::GetString(Int32).) |
![]() | GetTimeSpan | Gets the value of the specified column as a System.TimeSpan. |
![]() | GetType | Gets the Type of the current instance. (Inherited from Object.) |
![]() | GetValue | Gets the value of the column at the specified ordinal in its native format. (Overrides DbDataReader::GetValue(Int32).) |
![]() | GetValues | Populates an array of objects with the column values of the current row. (Overrides DbDataReader::GetValues(array<Object>).) |
![]() | InitializeLifetimeService | Obtains a lifetime service object to control the lifetime policy for this instance. (Inherited from MarshalByRefObject.) |
![]() | IsDBNull | Gets a value indicating whether the column contains non-existent or missing values. (Overrides DbDataReader::IsDBNull(Int32).) |
![]() | MemberwiseClone() | Creates a shallow copy of the current Object. (Inherited from Object.) |
![]() | MemberwiseClone(Boolean) | Creates a shallow copy of the current MarshalByRefObject object. (Inherited from MarshalByRefObject.) |
![]() | NextResult | Advances the OracleDataReader to the next result (Overrides DbDataReader::NextResult().) |
![]() | Read | Advances the OracleDataReader to the next record. (Overrides DbDataReader::Read().) |
![]() | ToString | Returns a string that represents the current object. (Inherited from Object.) |
| Name | Description | |
|---|---|---|
![]() ![]() | IDataRecord::GetData | For a description of this member, see IDataRecord::GetData. (Inherited from DbDataReader.) |
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.
Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2
The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.
