IDataParameter Interface
TOC
Collapse the table of content
Expand the table of content

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

NameDescription
System_CAPS_pubpropertyDbType

Gets or sets the DbType of the parameter.

System_CAPS_pubpropertyDirection

Gets or sets a value indicating whether the parameter is input-only, output-only, bidirectional, or a stored procedure return value parameter.

System_CAPS_pubpropertyIsNullable

Gets a value indicating whether the parameter accepts null values.

System_CAPS_pubpropertyParameterName

Gets or sets the name of the IDataParameter.

System_CAPS_pubpropertySourceColumn

Gets or sets the name of the source column that is mapped to the DataSet and used for loading or returning the Value.

System_CAPS_pubpropertySourceVersion

Gets or sets the DataRowVersion to use when loading Value.

System_CAPS_pubpropertyValue

Gets or sets the value of the parameter.

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 Configuring Parameters and Parameter Data Types.

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:

Item

Description

PrvParameter()

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 void AddSqlParameters() 
{
// ...
// create categoriesDataSet and categoriesAdapter
// ...

  categoriesAdapter.SelectCommand.Parameters.Add(
    "@CategoryName", SqlDbType.VarChar, 80).Value = "toasters";
  categoriesAdapter.SelectCommand.Parameters.Add(
    "@SerialNum", SqlDbType.Int).Value = 239;
  categoriesAdapter.Fill(categoriesDataSet);

}

.NET Framework
Available since 1.1
Return to top
Show:
© 2016 Microsoft