This document provides late-breaking or other information that supplements the Microsoft® Remote Data Service 1.5 documentation.
The following sections are included in this document:
Microsoft Remote Data Service (RDS) is a fast and efficient data connectivity and data publishing framework for applications hosted in 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® to Web developers who need to build distributed, data-intensive applications for use over corporate intranets and the Internet.
Change in Product Name
The name, Microsoft® Advanced Data Connector (ADC) is changing to Microsoft® Remote Data Service (RDS), a feature of Microsoft® ActiveX™ Data Objects (ADO). ADC has always relied on ADO and this change represents a move to more closely integrate and clarify the relationship between these two components. ADO is a programming interface which allows easy and flexible access to OLE DB and ODBC data sources. Remote Data Service builds on ADO to provide an easy, disconnected recordset, and remoting service. The functionality of Advanced Data Connector has not been affected by this change, and you will see a number of great new features with the release of version 1.5.
The following are new features in Remote Data Service 1.5. For more information on these features, refer to the documentation.
- Expanded updatability. You can now update data to all ODBC compliant data sources, and no longer need to use the “for browse” clause.
- ActiveX Data Objects (ADO) methods now also provide RDS remoting functionality from within ADO. This addition in programming model seamlessly integrates RDS into ADO.
- Sorting and filtering on Recordset objects.
- Added support for asynchronous execution and result set fetching. This allows the control to be handed back to the programmer or user without having to wait for a query to finish.
- Multiple output parameter support for business objects.
- The CreateRecordset method on the RDS.DataControl object, so custom Recordset objects can now be created on the client as well as on the RDSServer.DataFactory.
- The ConvertToString method on the RDSServer.DataFactory object.
- Safe array marshaling provides support for the Safe Array data type.
- Client impersonation provides support for IIS’ NT Challenge/Response password authentication feature.
Before you install Microsoft Remote Data Service, make sure that your client and server computers meet the minimum hardware and software requirements.
To install Remote Data Service, you must meet certain hardware requirements, which include the following:
- Any Microsoft® Windows NT® or Microsoft® Windows® 98 x86-compatible computer, or a Digital Equipment Corporation Alpha processor machine.
- A hard disk with a minimum of 8 megabytes (MB) available space for a full installation of all the updated components required for RDS to run.
- A minimum of 12 MB of RAM for client computers.
- A minimum of 24 MB of RAM for server computers (32 MB of RAM recommended).
Before you install Remote Data Service on a server computer, your server computer must meet the following software requirements:
- Any of the following operating system platforms: Windows NT 4.0 Server or Workstation with Service Pack 3 (SP3) or later. Remote Data Service currently supports the x86/Intel and Alpha platforms. For production data environments, the NT Server platform is strongly recommended.
- Microsoft® Internet Information Server (IIS) 3.0 or 4.0, with Microsoft® Active Server Pages.
- Microsoft® SQL Server 6.5 with Service Pack 2, or other ODBC 2.0 or greater (Level 1 compliant) data source.
To access Remote Data Service applications from client computers, client computers must meet the following software requirements:
- Any of the following operating system platforms: Windows 98, Windows NT Server 4.0 or later or Windows NT Workstation 4.0 or later.
- Microsoft® Internet Explorer version 4.0 or later.
Note Remote Data Service has not been tested with the Netscape browser technology.
To build client Web pages, you can use typical HTML authoring tools, such as Notepad or the more fully featured Microsoft ActiveX Control Pad.
To program server-side business objects, you can use any ActiveX™/COM DLL-compatible tool, such as Microsoft® Visual Basic® 4.0 or later, or Microsoft® Visual C++®.
Installing Microsoft Remote Data Service
For Remote Data Service to work correctly, you should ensure that the Remote Data Service server and client components are installed correctly. The server component is installed via the setup program (mdac_nts.exe for Windows NT Server; mdac_ntw.exe for Windows NT Workstation; mdac_95.exe for Windows 98; mdac_as for Alpha server; mdac_aw.exe for Alpha workstation) or with the IIS 4.0 integrated setup. The client files required are provided with Internet Explorer 4.0, so no .cab file or setup program is required.
Installing RDS Server Components on Your Web Servers
You will install the Microsoft Remote Data Service server components on your Web server computer, which should have Windows NT Server version 4.0 with SP3 or later. Setup assumes that your computer meets all of the software requirements.
To install Remote Data Service server components:
- From your Web server computer, connect to the Remote Data Service World Wide Web site at http://www.microsoft.com/data/rds/.
- Click Free Downloads in the left frame.
- Click the link for the installation you want (mdac_nts.exe for Windows NT Server; mdac_ntw.exe for Windows NT Workstation; mdac_95.exe for Windows 98; mdac_as.exe for Alpha server; mdac_aw.exe for Alpha workstation) to install the software and documentation.
- Close other programs which may be running.
- Follow the Setup instructions on the screen.
The Setup program installs the program files to the :\Program Files\Common Files\System\MSADC directory. (This location is adjacent to other complementary Microsoft technologies such as ActiveX Data Objects and OLE DB.) The following subdirectories are created under the \MSADC directory with the setup program.
|..\MSADC\Doc||Contains the documentation.|
|..\MSADC\Samples||Contains the sample files.|
|..\MSADC\Samples11||Contains the sample files for the RDS 1.1 client, if this was installed.|
The server installation program (mdac_nts.exe) also creates a Microsoft Internet Information Server virtual root on your Web server computer. The root is designated http:///msadc and you can use it to reference the files in that directory tree from the browser.
Once you have followed this procedure to set up Microsoft Remote Data Service on your Web server computer, you can validate your installation (see Validating Setup, below).
Installing RDS Client Components on Your Client Computers
Microsoft Internet Explorer 4.0 already includes the necessary Remote Data Service (RDS) client components. Therefore, you don’t need to include a .cab file on your Web page because client computers will already have the RDS client component DLLs. See the Technical Notes for a list of client files if your application needs to provide the client files.
You can use the ADCTest.asp sample application to validate your Microsoft Remote Data Service installation.
To validate setup with ADCTest:
- Start Internet Explorer, and enter the following address:
http:///MSADC/Samples/adctest.asp where is the name of your Web server. This should display the Remote Data Service Query Page. You’ll notice that the server, connection, and query information is already provided for you.
- Click Run to execute the query.
If the grid displays a resultset, your installation is correct.
If you run into any problems, review the setup instructions and see “Troubleshooting Remote Data Service” and “Other RDS Configuration Information” in online Help.
If you have a technical question about Remote Data Service, please refer to the Windows 98 documentation for the product support telephone number.
Visiting the Microsoft Remote Data Service Web Site
You can visit the Microsoft Remote Data Service Home Page on the World Wide Web for documentation updates and information about other related technologies. The address is http://www.microsoft.com/data/rds.
Joining the Remote Data Service Public Newsgroup
To facilitate discussion and information sharing, Microsoft has set up a public newsgroup: microsoft.public.ado.rds. You are welcome to post articles and messages to this unmoderated, unsupported newsgroup. Microsoft does not guarantee responses or direct support. For more information, visit the Remote Data Service Web site, http://www.microsoft.com/data/rds/.
- RDS (ADC) Beta 1 and Beta 2 clients and servers are not intended to be mixed with final release versions of RDS clients and servers. You should uninstall, and upgrade to the release version of the software to gain the benefit of product fixes and new features. The client files for RDS 1.5 are provided with Internet Explorer 4.0, so no .cab file or separate installation is required.
- Using FoxPro Databases
- Sample Applications
- When you install the sample applications, an attempt is made to create a user account (“adcdemo”) within Microsoft® SQL Server. If this account already exists, the installation will succeed, however, when you run the sample application you may receive a “login failed” message. You can edit the sample files to set the username and password to the actual test account information.
- “System error: Out of Virtual Memory” Error
- MDAC Client Files Provided with Internet Explorer 4.0
- If the install location name must be changed, the IIS vroot of /MSADC must remain. The file MSADCS.DLL requires it be located in the root directory of the /MSADC vroot.
- Cannot filter for NULL
- The RDS.DataControl features three events that are not mentioned in the documentation. These events are associated with asynchronous recordset population.
- The connection string for Remote Data Service typically references System DSNs with a syntax like “DSN=MyDSN;UID=SalesMgr;PWD=Secret;”. The syntax for using a File DSN would be “FileDSN=c:\MySQL.dsn;”.
If you access Visual FoxPro data, you must use the latest Visual FoxPro ODBC driver (version 126.96.36.1992 or later), which is available from http://www.microsoft.com/vfoxpro/vfdownload. If you don’t use the latest driver, you may not be able to execute queries correctly.
To load the grid in the RDS sample applications, you need to be able to access the Internet (as opposed to your intranet). If you try to load the samples that use the Sheridan grid, the Sheridan cab file referenced in the CODEBASE line attempts to download the mfc42.dll file patch from the Microsoft general fixes Web site. If it is unable to access this patch, the grid will not load. If the ActiveX control for the grid (ssdatb32.ocx) already resides on the client computer, the CODEBASE line will not need to unpack the .cab file, and the patch download prompt will not be encountered.
If you receive the error “System error: out of virtual memory error” from the Web Server requiring a reboot, the following may address the error. Your Web server machine may be out of virtual memory, or the SQL data source server may require more TempDB space to handle the size of the query you are attempting to run. Virtual memory can be adjusted from Control Panel (click the System icon, select the Performance tab, and click the Virtual Memory button to see if there is extra hard disk space available). More information on how to adjust the TempDB space can be found in the the “Performance” Help topic’s subtopic, “Ensuring Sufficient TempDB Space.”
For Web client convenience, the Microsoft Data Access Components client files are included with Internet Explorer version 4.0. Provided below is a list of files and their install locations if you wish to make these files available to your non-Internet Explorer client components using the MDAC server.
Files marked with an asterisk (*) should be self-registered with regsvr32.dll which can be found in the \system (or \system32) directory of your machine. The notation for \system below refers to \winnt\system32 directory on Windows NT machines, or \\system on Windows 98 machines. It is important that these files are consistently installed to these locations, to ensure that all programs which rely on them will continue to function correctly in this and later versions.
msadce.dll* – installed to \Program Files\Common Files\system\msadc msadcer.dll – installed to \Program Files\Common Files\system\msadc msadco.dll* – installed to \Program Files\Common Files\system\msadc msadcor.dll – installed to \Program Files\Common Files\system\msadc msader15.dll – installed to \Program Files\Common Files\system\ado msador15.dll* – installed to \Program Files\Common Files\system\ado msdadc.dll* – installed to \Program Files\Common Files\system\ole db msdaps.dll* – installed to \Program Files\Common Files\system\ole db msdaer.dll* – (Optional, for ADO error messages) installed to \Program Files\Common Files\system\ole db msdaerr.dll* – (Optional, for ADO error messages) installed to \Program Files\Common Files\system\ole db msr2c.dll* – installed to \system by Internet Explorer msr2cenu.dll – installed to \system by Internet Explorer wininet.dll* – installed to \system by Internet Explorer
msdatsrc.tlb – installed to \system
The Filter property is not currently able to search for Null values. The setting might be set as follows ‘zipcode’, ‘=’, ” (which gets converted to NULL by the VBScript code), followed by the Reset method to run the filter action. You will get a type mismatch error.
OnReadyStateChange – Fires whenever the ReadyState property changes. This event is not available in JScript.
OnDataSetComplete – Fires when all data is fetched.
OnDataSetChanged – Fires when a new Recordset is returned but not yet fully populated.
During an async fetch, the following sequence of events occurs:
OnReadyStateChange – The ReadyState property is set to adcReadyStateInteractive while data is being fetched.
OnDataSetComplete – All data is fetched, but ReadyState is still set to adcReadyStateInteractive.
OnReadyStateChange – The ReadyState property changes to adcReadyStateComplete.
To get a disconnected recordset via ADO, you can use the following syntax.
Rather than: cnn.Connectionstring = “provider=msdasql;dsn=MySQL;uid=SalesMgr;pwd=Secret” you can use: cnn.Connectionstring = “provider=MS Remote;Remote Server=http://MyServer;Remote Provider=msdasql;dsn=MySQL;uid=sa;pwd=”
The following is a list of Remote Data Service 1.5 known issues.
- The OnReadyStateChange async event is not issued. To work around this, you can test the following events and property for equivalent state:
OnDataSetChanged event will be issued when the Recordset exists, the query execution is complete, but not all rows are present. Immediately after the OnDataSetChanged event is issued, the ReadyState property is a value of 3.
OnDataSetComplete event will be issued when the Recordset exists, and all rows are present. Immediately after the OnDataSetComplete event is issued the ReadyState property a value of 4.
- If you receive an error in Setup about the MTXOCI.DLL, your machine may have an older version of Microsoft Transaction Server (MTS). To resolve this issue, upgrade to the newest version of MTS, which provides this necessary file.
- Version 188.8.131.526 of the Visual Basic Script DLL (vbscript.dll) contains a memory leak. An updated version of the DLL (184.108.40.2064 or later) resolves the issue. It is available with Internet Information Server 3.0, and can be downloaded from http://www.microsoft.com/vbscript.
- The file msdaps.dll will register and work correctly. Currently it is unable to unregister, however. This will only affect uninstall, and not the functionality of the product. This may be resolved in NT Service Pack 4.
- When using Microsoft SQL Server 6.5 with SQL Server Service Pack 3 installed, an UPDATE, INSERT, or DELETE will fail if attempted against a self-join. An error will occur on the line of code containing the SubmitChanges method.
- The adctest.asp sample will silently fail unless the machine it is running on has access to the internet (as opposed to an intranet). The application needs to load some dll’s from microsoft.com.
- The language reference topics for the Reset method and the SortColumn, SortDirection, FilterValue, FilterCriterion, and FilterColumn properties all state that execution of the Reset method replaces the existing RDS.DataControl object’s Recordset with a read-only Recordset. This is incorrect; the new Recordset is updatable.
- When using an ORDER BY clause in a query against Microsoft SQL server with Microsoft SQL Server Sevice Pack 3 installed, and returning an updatable client-side cursor, columns referenced in the ORDER BY clause must also be referenced in the SELECT clause.
- The ODBC driver for Informix databases does not support transactions (being able to roll back a change to the data). RDS does not support updating to drivers without transactions support. Attempting to call SubmitChanges will give the following error, “The operation requested by the application is not supported by the provider.”
© 1997 Microsoft Corporation
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