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IDataParameter Interface

Represents a parameter to a Command object, and optionally, its mapping to DataSet columns; and is implemented by .NET Framework data providers that access data sources.

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

Public Interface IDataParameter
Dim instance As IDataParameter

public interface IDataParameter
public interface IDataParameter
Not applicable.

The IDataParameter interface allows an inheriting class to implement a Parameter class, which represents a parameter to a Command object. For more information about Parameter classes, see Using Stored Procedures with a Command. For more information about implementing .NET Framework data providers, see Implementing a .NET Framework Data Provider.

An application does not create an instance of the IDataParameter interface directly, but creates an instance of a class that inherits IDataParameter.

Classes that inherit IDataParameter must implement the inherited members, and typically define additional members to add provider-specific functionality. For example, the IDataParameter interface defines the DbType property. In turn, the OleDbParameter class inherits this property, and also defines the OleDbType property.

Notes to Implementers: To promote consistency among .NET Framework data providers, name the inheriting class in the form Prv Parameter where Prv is the uniform prefix given to all classes in a specific .NET Framework data provider namespace. For example, Sql is the prefix of the SqlCommand class in the System.Data.SqlClient namespace. When you inherit from the IDataParameter interface, you should implement the following constructors:




Initializes a new instance of the Parameter class.

PrvParameter(string name, PrvDbType dataType)

Initializes a new instance of the Parameter class with the parameter name and data type.

PrvParameter(string name, object value)

Initializes a new instance of the Parameter class with the parameter name and an object that is the value of the Parameter.

PrvParameter(string name, PrvDbType dataType, int size)

Initializes a new instance of the Parameter class with the parameter name, data type, and width.

PrvParameter(string name, PrvDbType dataType, int size, string srcColumn)

Initializes a new instance of the DbParameter class with the parameter name, data type, width, and source column name.

PrvParameter(string parameterName, PrvDbType dbType, int size, ParameterDirection direction, Boolean isNullable, Byte precision, Byte scale, string srcColumn, DataRowVersion srcVersion, object value)

Initializes a new instance of the OleDbParameter class with the parameter name, data type, width, source column name, parameter direction, numeric precision, and other properties.

The following example creates multiple instances of the derived class, SqlParameter, through the SqlParameterCollection collection within the SqlDataAdapter. These parameters are used to select data from the data source and place the data in the DataSet. This example assumes that a DataSet and a SqlDataAdapter have already been created with the appropriate schema, commands, and connection.

Public Sub AddSqlParameters()
    ' ...
    ' create categoriesDataSet and categoriesAdapter
    ' ...
    categoriesAdapter.SelectCommand.Parameters.Add( _
        "@CategoryName", SqlDbType.VarChar, 80).Value = "toasters"
    categoriesAdapter.SelectCommand.Parameters.Add( _
        "@SerialNum", SqlDbType.Int).Value = 239
End Sub  

Windows 98, Windows Server 2000 SP4, Windows CE, Windows Millennium Edition, Windows Mobile for Pocket PC, Windows Mobile for Smartphone, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition

The Microsoft .NET Framework 3.0 is supported on Windows Vista, Microsoft Windows XP SP2, and Windows Server 2003 SP1.

.NET Framework

Supported in: 3.0, 2.0, 1.1, 1.0

.NET Compact Framework

Supported in: 2.0, 1.0

XNA Framework

Supported in: 1.0

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