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
'宣言
Protected Overridable Function OnDeriveSchema ( _
command As String, _
commandType As DataCommandType, _
parameters As IVsDataParameter(), _
commandTimeout As Integer _
) As IVsDataReader
'使用
Dim command As String
Dim commandType As DataCommandType
Dim parameters As IVsDataParameter()
Dim commandTimeout As Integer
Dim returnValue As IVsDataReader
returnValue = Me.OnDeriveSchema(command, _
commandType, parameters, commandTimeout)
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
)
protected function OnDeriveSchema(
command : String,
commandType : DataCommandType,
parameters : IVsDataParameter[],
commandTimeout : int
) : IVsDataReader
Parameters
command
Type: System.StringThe command for which the schema is derived.
commandType
Type: Microsoft.VisualStudio.Data.Services.SupportEntities.DataCommandTypeA 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: []A list of parameters to pass with the command.
commandTimeout
Type: System.Int32Amount 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.
Permissions
- 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.