IDataRecord Interface

 

Provides access to the column values within each row for a DataReader, and is implemented by .NET Framework data providers that access relational databases.

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

public interface IDataRecord

NameDescription
System_CAPS_pubpropertyFieldCount

Gets the number of columns in the current row.

System_CAPS_pubpropertyItem[Int32]

Gets the column located at the specified index.

System_CAPS_pubpropertyItem[String]

Gets the column with the specified name.

NameDescription
System_CAPS_pubmethodGetBoolean(Int32)

Gets the value of the specified column as a Boolean.

System_CAPS_pubmethodGetByte(Int32)

Gets the 8-bit unsigned integer value of the specified column.

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.

System_CAPS_pubmethodGetChar(Int32)

Gets the character value of the specified column.

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.

System_CAPS_pubmethodGetData(Int32)

Returns an IDataReader for the specified column ordinal.

System_CAPS_pubmethodGetDataTypeName(Int32)

Gets the data type information for the specified field.

System_CAPS_pubmethodGetDateTime(Int32)

Gets the date and time data value of the specified field.

System_CAPS_pubmethodGetDecimal(Int32)

Gets the fixed-position numeric value of the specified field.

System_CAPS_pubmethodGetDouble(Int32)

Gets the double-precision floating point number of the specified field.

System_CAPS_pubmethodGetFieldType(Int32)

Gets the Type information corresponding to the type of Object that would be returned from GetValue.

System_CAPS_pubmethodGetFloat(Int32)

Gets the single-precision floating point number of the specified field.

System_CAPS_pubmethodGetGuid(Int32)

Returns the GUID value of the specified field.

System_CAPS_pubmethodGetInt16(Int32)

Gets the 16-bit signed integer value of the specified field.

System_CAPS_pubmethodGetInt32(Int32)

Gets the 32-bit signed integer value of the specified field.

System_CAPS_pubmethodGetInt64(Int32)

Gets the 64-bit signed integer value of the specified field.

System_CAPS_pubmethodGetName(Int32)

Gets the name for the field to find.

System_CAPS_pubmethodGetOrdinal(String)

Return the index of the named field.

System_CAPS_pubmethodGetString(Int32)

Gets the string value of the specified field.

System_CAPS_pubmethodGetValue(Int32)

Return the value of the specified field.

System_CAPS_pubmethodGetValues(Object[])

Populates an array of objects with the column values of the current record.

System_CAPS_pubmethodIsDBNull(Int32)

Return whether the specified field is set to null.

The IDataReader and IDataRecord interfaces enable an inheriting class to implement a DataReader class. This provides a way of reading one or more forward-only streams of result sets. For more information about DataReader classes, see Retrieving Data Using a DataReader.

An application does not create an instance of the IDataRecord interface directly, but creates an instance of a class that inherits IDataRecord. Typically, you do this by obtaining a DataReader through the ExecuteReader method of the Command object.

Classes that inherit IDataRecord must implement all inherited members, and typically define additional members to add provider-specific functionality.

Providers implementing a DataReader are required to expose data in common language runtime (CLR) types. Type coercion is defined for some types not included in the CLR. These values may be accessed as alternative types that comply with CLR types. As an example, the following table lists suggested mappings from OLE DB data types to CLR types, with alternative types in parentheses.

OLE DB type

CLR type

DBTYPE_BOOL

Int16

DBTYPE_BSTR

string

DBTYPE_BYTES

byte[]

DBTYPE_CY

Decimal

DBTYPE_DATE

DateTime

DBTYPE_DBDATE

DateTime

DBTYPE_DBTIME

DateTime

DBTYPE_DBTIMESTAMP

DateTime

DBTYPE_DECIMAL

Decimal

DBTYPE_EMPTY

null

DBTYPE_ERROR

ExternalException

DBTYPE_FILETIME

DateTime

DBTYPE_GUID

Guid

DBTYPE_HCHAPTER

not supported

DBTYPE_I1

SByte

DBTYPE_I2

Int16

DBTYPE_I4

Int32

DBTYPE_I8

Int64

DBTYPE_IDISPATCH

object

DBTYPE_IUNKNOWN

object

DBTYPE_NULL

DBNull.Value

DBTYPE_NUMERIC

Decimal

DBTYPE_PROPVARIANT

object

DBTYPE_R4

Single

DBTYPE_R8

Double

DBTYPE_STR

string

DBTYPE_UDT

not supported

DBTYPE_UI1

byte (Int16)

DBTYPE_UI2

UInt16 (Int32)

DBTYPE_UI4

UInt32 (Int64)

DBTYPE_UI8

UInt64 (Decimal)

DBTYPE_VARIANT

object

DBTYPE_VARNUMERIC

not supported

DBTYPE_WSTR

string

The following example creates instances of the derived classes, SqlConnection, SqlCommand, and SqlDataReader. The example reads through the data, writing it out to the console. Finally, the example closes the SqlDataReader, and then the SqlConnection.

using System;
using System.Data;
using System.Data.SqlClient;


class Program
{
    static void Main()
    {
        string str = "Data Source=(local);Initial Catalog=Northwind;"
            + "Integrated Security=SSPI";
        ReadOrderData(str);
    }

    private static void ReadOrderData(string connectionString)
    {
        string queryString =
            "SELECT OrderID, CustomerID FROM dbo.Orders;";

        using (SqlConnection connection =
                   new SqlConnection(connectionString))
        {
            SqlCommand command =
                new SqlCommand(queryString, connection);
            connection.Open();

            SqlDataReader reader = command.ExecuteReader();

            // Call Read before accessing data.
            while (reader.Read())
            {
                ReadSingleRow((IDataRecord)reader);
            }

            // Call Close when done reading.
            reader.Close();
        }
    }

    private static void ReadSingleRow(IDataRecord record)
    {
        Console.WriteLine(String.Format("{0}, {1}", record[0], record[1]));
    }

}

.NET Framework
Available since 1.1
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