1. What’s new in ADO 2.5 Greg Hinkel Program Manager Data Access Group mdac@microsoft.com

3. Agenda  ADO - Overview  Semi-structured Data  ADO 2.5 - Programming Model  URL binding for ADO Objects  Record Object  Stream Object  Performance and XML  Summary

4. ADO Overview  A single, powerful consumer interface for data exposed by OLE DB providers  For use in Web-based, Client/Server and distributed applications  Works with many languages (Visual Basic ®, Visual C++ ®, Visual J++ ™, Visual Basic Scripting Edition)  High Performance  Simple Object Model

5. Semi-structured data  Data that is: More structured than a BLOB More structured than a BLOB Structured differently than a relational database table Structured differently than a relational database table  Examples: A file system A file system Email data Email data An arbitrary XML stream An arbitrary XML stream Web pages Web pages

6. Semi-structured data  Data tends to be organized hierarchically, like a tree Hierarchies have arbitrary depth Hierarchies have arbitrary depth  Each node in the tree has a set of properties Each node may have a unique set of properties Each node may have a unique set of properties  Leaf-nodes associated with a special “Value” property  Non-leaf nodes are collections of other nodes

7. Semi-structured data: Requirements  Node Operations Get/Set properties, Add/Delete properties Get/Set properties, Add/Delete properties  Scoped Operations Move, Copy, Delete operations apply to all contained nodes Move, Copy, Delete operations apply to all contained nodes  Querying A list of nodes that satisfy a predicate on properties A list of nodes that satisfy a predicate on properties  Lightweight Operations such as reading email properties, etc. are done many times Operations such as reading email properties, etc. are done many times

8. ADO 2.5 - Design Goals  Keep it simple!  Allow ADO objects to be opened with URL strings  Extend ADO to work with tree- structured & hierarchical data sources  Provide the ability to do scoped operations  Extend ADO so that it may be used to read and manipulate binary streams

9. Modeling semi-structured data with ADO 2.5  Collections are modeled as recordsets Common properties are modeled as fields of the recordset Common properties are modeled as fields of the recordset Folders, Directories Folders, Directories  Nodes are modeled as a record object Properties are modeled as fields of the record object Properties are modeled as fields of the record object Files, Email folder objects Files, Email folder objects  Contents of a record can be manipulated by the Stream object

10. ADO 2.1 - Object Model Connection Command Recordset Errors Parameters

11. ADO 2.5 - Object Model Connection Command Recordset Errors Fields Parameters RecordStream

12. URL Naming for ADO  URLs can be used to directly identify objects in a data source nodes in a hierarchical namespace (files and folders) nodes in a hierarchical namespace (files and folders) table in a relational database, unique rows in a table table in a relational database, unique rows in a table  Record object represents a unique object file, folder, table, row file, folder, table, row  Recordset object represents the contents of a collection object rows of a table, files in a folder rows of a table, files in a folder

13. URL binding in ADO 2.5  ADO 2.5 allows URL naming for Connection, Recordset, Record, and Stream objects Connection, Recordset, Record, and Stream objects For a Recordset, URL must point to a collection type node For a Recordset, URL must point to a collection type node For stream, URL must point to an object with a default stream defined For stream, URL must point to an object with a default stream defined  The RootBinder cracks URLs and calls the right provider  New record objects can also be created directly

14. URL naming - sample code Sub RsOpen() Dim cn As New ADODB.Connection Dim rs As New ADODB.Recordset Dim rs1 as New ADODB.Recordset cn.Open “URL=http://server01/myfolder” rs1.Open “mysubfolder”, cn rs.Open “URL=http://server01/myfolder",, _ adOpenForwardOnly, _ adLockReadOnly End Sub

15. Record Object (1 of 2)  New automation object implemented in ADO 2.5  Models an entity that has a collection of properties and (possibly) nested entities Email, Files, web pages, structured documents, folders, XML node, Databases, Tables, etc. Email, Files, web pages, structured documents, folders, XML node, Databases, Tables, etc. can also represent a row of a recordset can also represent a row of a recordset Email/File contents appear as a stream property Email/File contents appear as a stream property

16. Record Object (2 of 2)  Expresses the notion of containment & scoping Folders contain other folders and files Folders contain other folders and files Folder operations such as move, copy, etc. apply within the folder’s scope Folder operations such as move, copy, etc. apply within the folder’s scope  Properties are modeled as a collection of Fields  Containment is modeled as Sub-Records Records can be viewed in a tabular form as a recordset Records can be viewed in a tabular form as a recordset  Properties and methods are implemented to operate on the record object

17. Opening a Record Object   Many ways to open a record object Open directly using a URL that uniquely identifies it From an ADO recordset by specifying an individual record From a field’s value property  Record object always exists in the context of a Connection object connection object is either implicitly created or explicitly specified connection object is either implicitly created or explicitly specified

18. Record Properties

19. Record Methods

20. The Record Object ‘opens an existing record object or creates a new one Sub OpenFolderIfExists() Dim rec As New Record Dim rs As Recordset Dim rs As Recordset rec.Open "TestFolder", "URL=http://adot20/davfs/greghin/",, adOpenIfExists Or adCreateCollection rec.Open "TestFolder", "URL=http://adot20/davfs/greghin/",, adOpenIfExists Or adCreateCollection Debug.Print "Record is Collection : " & Str(rec.RecordType) Debug.Print "Record is Collection : " & Str(rec.RecordType) Debug.Print rec.CopyRecord(, "http://adot20/davfs/greghin/TestSubFolder") Debug.Print rec.CopyRecord(, "http://adot20/davfs/greghin/TestSubFolder") Set rs = rec.GetChildren Set rs = rec.GetChildren While Not rs.EOF While Not rs.EOF Debug.Print rs(0) Debug.Print rs(0) rs.MoveNext rs.MoveNext Wend Wend End Sub

21. Fields of a Record object  A field represents a property associated with a record object Title, size, modified time of a file, folder, email message Title, size, modified time of a file, folder, email message  Fields are implemented as a collection on the record object  Methods and properties are same as that on recordset’s field object  New fields can be added to the collection of an already open record object

22. The Recordset Object  When a record is a collection (such as a folder), it has other records contained in it  A view of contained records is available as a recordset tabular view as opposed to the tree view tabular view as opposed to the tree view  Use GetChildren method on the Record object opens the default contents recordset - pre- defined schema for document source providers opens the default contents recordset - pre- defined schema for document source providers  Execute a command against a folder Ability to search on properties Ability to search on properties  Use Record and Recordset for navigation URL is one of the fields on the contents recordset & can be used to open the contained records URL is one of the fields on the contents recordset & can be used to open the contained records

23. Recordsets with Variable # of Columns  Many data sources generate recordsets where each row has a different set of columns  Case in point: Contents of a mail folder An email folder has different properties from the Contacts folder An email folder has different properties from the Contacts folder  Case in point: An XML stream Each element may have a different set of attributes Each element may have a different set of attributes  Case in point: The Contents recordset Each file in a folder has different set of properties Each file in a folder has different set of properties

24. Supporting Variable Column Recordsets  The fields collection on the recordset contains the set of “common” fields From address, subject, receive date, etc. for email From address, subject, receive date, etc. for email File name, size, last modified, etc. for files File name, size, last modified, etc. for files  Each record has a set of fields unique to that row This is a superset of the common columns that exist for the recordset This is a superset of the common columns that exist for the recordset  To view the variable fields, obtain a record object from the recordset and then use its fields collection

25. Relationship between the Record & Recordset Objects  Record’s field collection Superset of the fields collection on the associated source recordset, if any Superset of the fields collection on the associated source recordset, if any  It is possible to add/delete fields from an already open record object only for fields that are unique to that record only for fields that are unique to that record  Record behaves in the same update mode as its source recordset if no source recordset, then in immediate update mode if no source recordset, then in immediate update mode

26. Working with the Recordset Object 'open Recordset Sub OpenRecordset() Dim rs As New ADODB.Recordset Dim rec As New ADODB.Record Dim cn As New ADODB.Connection stSrc = "http://server02/myfolder/testfolder" http://server02/myfolder/testfolder rs.Open stSrc,, _ adOpenForwardOnly, _ adLockReadOnly, _ adCmdURLBindrs.MoveNext rec.Open rs End Sub

27. Working with the Fields collection Sub RSFields() Dim rs As New Recordset Dim rec as new Record stURL = "http://server01/myfolder" http://server01/myfolder rs.Open stURL,,,, adCmdURLBind while rs.eof <> True rec.Open rs For i = 0 To rec.Fields.Count - 1 Debug.Print rec.fields(I).name, “=“, _ rec.fields(I).value rec.fields(I).value Next I rs.MoveNextWend End Sub

28. Stream Object  A new ADO 2.5 object  An automation object used to manipulate the contents of a binary/textual stream  Implemented on top of IStream interface  Record objects usually have a default stream associated with them content of an email message, default document for a web folder content of an email message, default document for a web folder  BLOB/Text fields in a database may also be viewed as a stream object

29. Stream Properties

30. Stream Methods (1 of 3) Open ([Source as variant], [Mode as ModeEnum = adoModeUnknown], [Options as StreamOpenOptionsEnum = adOpenFromURL], [uid as string], [pwd as string])

31. Stream Methods (2 of 3) ReadText ([NumChar as long = adReadAll]) as String WriteText (StrChars as string, [Options as StreamWriteOptionsEnum = adWriteChar])

32. Stream Methods (3 of 3) CopyTo(destStream as stream, [NumChars as integer = - 1]) LoadFromFile (strFileName as string) SaveToFile(FileName as string, [SaveOptions as SaveOptionsEnum = adSaveCreateNotExist])

33. Working with the Stream object Sub StmOperations() Dim Stm as New ADODB.Stream stURL = "http://server01/myfolder/mydoc.doc" http://server01/myfolder/mydoc.doc Stm.Open stURL Debug.Print Stm.Size Debug.Print Stm.Type Debug.Print Stm.ReadText Stm.SaveToFile “c:\my documents\copyofmydoc.doc” End Sub

34. ADO 2.5 - Summary  Extends core ADO to work with semi- structured data exposed by new data sources  Enables web-publishing and document management through scripting languages  Shipping in MDAC 2.5 with Windows 2000 Will be available in Beta3 Will be available in Beta3

35. Performance  ADO 2.5 is faster than ADO 2.1  We wrote our own IDispatch for scripting languages  Much better on multiple processor machines

36. XML  rs.Save Response, adPersistXML  rs.Open Request

37. Questions?