AdoDotNetSchemaReader Class

Artikel
02/28/2011

Provides a means for obtaining the schema of the DbDataReader object that encapsulates the result set.

Inheritance Hierarchy

System.Object
Microsoft.VisualStudio.Data.Framework.DataReader
Microsoft.VisualStudio.Data.Framework.AdoDotNet.AdoDotNetSchemaReader

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

Syntax

'Declaration
Public Class AdoDotNetSchemaReader _
    Inherits DataReader

public class AdoDotNetSchemaReader : DataReader

public ref class AdoDotNetSchemaReader : public DataReader

type AdoDotNetSchemaReader =  
    class
        inherit DataReader
    end

public class AdoDotNetSchemaReader extends DataReader

The AdoDotNetSchemaReader type exposes the following members.

Constructors

	Name	Description
	AdoDotNetSchemaReader(DbDataReader)	Initializes a new instance of the AdoDotNetSchemaReader class with a data reader object.
	AdoDotNetSchemaReader(DbDataReader, DbCommand)	Initializes a new instance of the AdoDotNetSchemaReader class with a data reader object and a data command object.

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Properties

	Name	Description
	Descriptor	Gets information that describes the data from a data source. (Inherited from DataReader.)
	HasDescriptor	Gets a value indicating whether the data parameter exposes its IVsDataReaderDescriptor implementation through the Descriptor() property. (Overrides DataReader.HasDescriptor.)
	IsClosed	Gets a value indicating whether the AdoDotNetSchemaReader is closed. (Overrides DataReader.IsClosed.)
	ItemCount	Gets an integer value specifying the number of data items contained in the current AdoDotNetSchemaReader instance. (Overrides DataReader.ItemCount.)
	SchemaTable	Gets the DataTable object that represents the schema of the DbDataReader passed into the constructor of the AdoDotNetSchemaReader.
	Status	Gets a numerical status code returned by the method currently providing data to the DataReader object. (Overrides DataReader.Status.)

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Methods

	Name	Description
	Close	Closes the current AdoDotNetSchemaReader instance. (Overrides DataReader.Close().)
	Dispose()	Releases managed resources held for the current DataReader instance. (Inherited from DataReader.)
	Dispose(Boolean)	Cleans up resources associated with the current DataReader instance, both when the public Dispose method is called and when the object is finalized with a call to the Finalize method. (Inherited from DataReader.)
	Equals	Determines whether the specified Object is equal to the current Object. (Inherited from Object.)
	Finalize	Finalizes the current DataReader instance. (Inherited from DataReader.)
	GetBytes(String, array<Byte[], Int32, Int32)	Retrieves a specified number of bytes of raw binary data. (Inherited from DataReader.)
	GetBytes(Int32, array<Byte[], Int32, Int32)	Reads a stream of bytes into the buffer as an array, starting at a specified offset. (Overrides DataReader.GetBytes(Int32, array<Byte[], Int32, Int32).)
	GetHashCode	Serves as a hash function for a particular type. (Inherited from Object.)
	GetItem(Int32)	Retrieves a data item at a specified index. (Overrides DataReader.GetItem(Int32).)
	GetItem(String)	Retrieves a data item with a specified name. (Overrides DataReader.GetItem(String).)
	GetItemIndex	Retrieves the index of the item for the given item name, such as the index of a column for a given column name. (Overrides DataReader.GetItemIndex(String).)
	GetItemMaxLength	Retrieves an integer value specifying the maximum length of the data item at the specified index. (Overrides DataReader.GetItemMaxLength(Int32).)
	GetItemName	Retrieves the string literal name of the data item at the specified index. (Overrides DataReader.GetItemName(Int32).)
	GetItemType(Int32)	Retrieves the data type of a data item, or items, at the specified index for the default format Default. (Inherited from DataReader.)
	GetItemType(Int32, DataItemTypeFormat)	Retrieves the data type for a data item at a specified index and with a specified item type format. (Overrides DataReader.GetItemType(Int32, DataItemTypeFormat).)
	GetType	Gets the Type of the current instance. (Inherited from Object.)
	IsNullItem(Int32)	Retrieves a Boolean value indicating whether the data item at the specified index is nulla null reference (Nothing in Visual Basic). (Overrides DataReader.IsNullItem(Int32).)
	IsNullItem(String)	Retrieves a Boolean value indicating whether the data item value for the specified data item name is nulla null reference (Nothing in Visual Basic). (Overrides DataReader.IsNullItem(String).)
	MemberwiseClone	Creates a shallow copy of the current Object. (Inherited from Object.)
	NextResult	Tests whether there is another result set and, if true, advances the AdoDotNetSchemaReader. (Overrides DataReader.NextResult().)
	Read	Tests whether there is another data record and, if true, advances the AdoDotNetSchemaReader to the next record. (Overrides DataReader.Read().)
	Terminate	Terminates the DataReader object immediately, without necessarily returning all of the data or setting output parameters. (Overrides DataReader.Terminate().)
	ToString	Returns a string that represents the current object. (Inherited from Object.)

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Remarks

Implements the IVsDataReader and the IVsDataReaderDescriptor interfaces. This class takes as input a DbDataReader object and exposes the schema of the DbDataReader object as a DDEX DataReader.

The format of the data reader exposed is that required by the DeriveSchema(String, DataCommandType, array<IVsDataParameter[], Int32) method, which has a fixed set of columns. It does not expose exactly the same information that is provided when calling the GetSchemaTable method on the underlying DbDataReader instance.

Thread Safety

Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.

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