|
|
|
| This is only the first few lines of this paper. If you would like to view the entire paper you need to register for free here. If you are already a member then login here. |
| Word Count: |
3518 |
Featured Papers from DirectEssays
1. servers
|
|
|
Microsoft(R) ActiveX(R) Data Objects version 2.0
|
|
|
-------- CONTENTS -------- 1. PRODUCT DESCRIPTION 2. NEW FEATURES 2.1 Asynchronous Connection, Execution, Fetching, and Events 2.2 Data Shaping 2.3 Persistence 2.4 Fabricated Recordset Objects 2.5 Sort, Filter, and Find 2.6 ADO Extensions for VC++ 2.7 ADO Support for Visual Analyzer (Microsoft Visual Studio(TM), Enterprise Edition Only) 2.8 Conflict Resolution for Client Cursors 2.9 Customizable DataFactory Behavior 3. TECHNICAL NOTES 3.1 Security Enhancements 3.2 Restrictive Behavior 3.3 Customizing Security Settings 4. KNOWN BUGS, LIMITATIONS, WORKAROUNDS, AND LATE-BREAKING DOCUMENTATION NOTES ---------------------- 1. PRODUCT DESCRIPTION ---------------------- ActiveX Data Objects (ADO) is an Automation-based interface for accessing data. ADO uses the OLE DB interface to access a broad range of data sources, including but not limited to data provided via ODBC. Users of RDO and DAO should quickly become comfortable with programming to ADO because the overall design of ADO comes from our experience in developing those interfaces. Microsoft Remote Data Service (RDS) is a component of ADO that provides fast and efficient data connectivity and the data publishing framework for applications hosted in Microsoft Internet Explorer. It is based on a client/server, distributed technology that works over HTTP, HTTPS (HTTP over Secure Sockets layer), and DCOM application protocols. Using data-aware ActiveX controls, RDS provides data access programming in the style of Microsoft Visual Basic(R) to Web developers who need to build distributed, data-intensive applications for use over corporate intranets and the Internet. --------------- 2. NEW FEATURES --------------- ADO 2.0 adds several new features for developers. 2.1 Asynchronous Connection, Execution, Fetching, and Events As did RDO 2.0, ADO now supports asynchronous operations. Asynchronous operations allow you to cancel out of an extended operation or to continue processing while waiting for the connection to complete. Events notify you when an asynchronous operation has been completed. Asynchronous fetching is a feature specific to the client cursor (CursorLocation = adUseClient), which returns the first rows from a query result and then continues fetching in the background while you manipulate the rows that have already been fetched. 2.2 Data Shaping In conjunction with the MSDataShape provider, ADO can expose data hierarchically. ADO can also expose grouping and aggregation over a recordset. 2.3 Persistence You can now save a Recordset object right to your local hard drive and load it later (when working with client cursors). This allows you to connect to the server, execute a query, call rst.Save("myfilename"), shut down the computer, and later call rs.Open("myfilename",,,adCmdFile) and modify the data. 2.4 Fabricated Recordset Objects You can create Recordset objects in ADO 2.0 without executing a query against the data source. Just create a new Recordset object, append some Field objects, call rst.Open(), and you now have a Recordset object that you can append data to, remote, and treat just as if the Recordset object had been created from a query. 2.5 Sort, Filter, and Find Allows you to manipulate results at the client when using client cursors. 2.6 ADO Extensions for VC++ Provides improved performance for VC++ users by enabling the use of native data types instead of Variants in C++ code. 2.7 ADO Support for Visual Analyzer (Microsoft Visual Studio, Enterprise Edition Only) ADO works with Visual Analyzer, submitting events to help in analyzing performance. 2.8 Conflict Resolution for Client Cursors Provides enhanced functionality for Recordset objects built with client-side cursors in two-tier scenarios. New functions, like Resync and Update, with conflict resolution are now supported on client cursors. 2.9 Customizable DataFactory Behavior Implicit remoting behavior is customizable now via the DataFactory Handler object implementation. DataFactory handler can be used to customize the open and batchupdate behavior of Recordset objects opened via RDS. You have a choice of writing a new handler yourself or using the default handler (MSDFMAP.dll) that ships with RDS 2.0. The behavior of the default handler can be driven by editing the default INI file it uses -- MSDFMAP.INI. ------------------ 3. TECHNICAL NOTES ------------------ 3.1 Security Enhancements This release includes security enhancements for ADO and RDS objects so that some of the operations are restricted when Internet Explorer is running in a "safe" mode. 3.1.1. Zones You can set different security settings for different "zones" in Internet Explorer 4.0 to customize the behavior of ADO/RDS objects in those zones. The following four zones are defined in Internet Explorer 4.0: * Internet zone * Local intranet zone * Restricted sites zone * Trusted sites zone 3.1.2. Security Levels For each of these zones, you can specify the security level to use. The following security levels are available for each zone: * High * Medium * Low * Custom Like any other ActiveX controls, in order for ADO/RDS objects to work at all in Internet Explorer 4.0, the security level must be set to "Medium" or "High." Custom settings are used to set ADO/RDS objects to behave in safe or unsafe mode. 3.2 Restrictive Behavior By default, any unsafe operations on ADO/RDS objects in Internet Explorer 4.0 will result in a user prompt when accessing pages from "Local trusted zone," "Trusted sites zone," and "Internet zone." Unsafe operations on ADO/RDS objects are disabled, by default, for pages loaded from "Restricted sites zone." The following describes ADO/RDS behavior when running in these modes: 3.2.1 Safe Objects The following objects are considered "safe." This means that unsafe operations (detailed in 3.2.3) are disallowed in a safe environment (e.g., Internet Explorer, by default; unless custom settings are used to run in an unsafe mode) and allowed in an unsafe environment (e.g., Visual Basic).
|
|
|
|
Still Can't Find What Your Looking For? Then Try a Essay Search!
|
