DataAsyncCommand.OnDeriveSchema Method

Dispatches the asynchronous derive schema operation to the synchronous DeriveSchema method call.

Namespace:  Microsoft.VisualStudio.Data.Framework
Assembly:  Microsoft.VisualStudio.Data.Framework (in Microsoft.VisualStudio.Data.Framework.dll)

Syntax

'Declaration
Protected Overridable Function OnDeriveSchema ( _
    command As String, _
    commandType As DataCommandType, _
    parameters As IVsDataParameter(), _
    commandTimeout As Integer _
) As IVsDataReader

protected virtual IVsDataReader OnDeriveSchema(
    string command,
    DataCommandType commandType,
    IVsDataParameter[] parameters,
    int commandTimeout
)

protected:
virtual IVsDataReader^ OnDeriveSchema(
    String^ command, 
    DataCommandType commandType, 
    array<IVsDataParameter^>^ parameters, 
    int commandTimeout
)

abstract OnDeriveSchema : 
        command:string * 
        commandType:DataCommandType * 
        parameters:IVsDataParameter[] * 
        commandTimeout:int -> IVsDataReader  
override OnDeriveSchema : 
        command:string * 
        commandType:DataCommandType * 
        parameters:IVsDataParameter[] * 
        commandTimeout:int -> IVsDataReader

protected function OnDeriveSchema(
    command : String, 
    commandType : DataCommandType, 
    parameters : IVsDataParameter[], 
    commandTimeout : int
) : IVsDataReader

Parameters

• command
  Type: System.String

  The command for which the schema is derived.

• commandType
  Type: Microsoft.VisualStudio.Data.Services.SupportEntities.DataCommandType

  A value from the DataCommandType enumeration representing the command type for the indicated command. The value specifies how to interpret the contents of the command parameter.

• parameters
  Type: array<Microsoft.VisualStudio.Data.Services.SupportEntities.IVsDataParameter[]

  A list of parameters to pass with the command.

• commandTimeout
  Type: System.Int32

  Amount of time, in seconds, before which the command times out.

Return Value

Type: Microsoft.VisualStudio.Data.Services.SupportEntities.IVsDataReader
An IVsDataReader object. This object provides a forward-only, read-only data stream that describes the layout of items and blocks, that is, the schema, for the reader object returned upon executing the specified command.

.NET Framework Security

• Full trust for the immediate caller. This member cannot be used by partially trusted code. For more information, see Using Libraries from Partially Trusted Code.

See Also

Reference

DataAsyncCommand Class

Microsoft.VisualStudio.Data.Framework Namespace