"Larry Linson" <bo*****@localhost.not> wrote in
news:sBojf.5220$3x2.1886@trnddc07:
"Lyle Fairfield" <ly***********@aim.com> wrote
Sure they are. And sometimes when the Gestado
aren't paying attention, ADO answers are
allowed too.
Is this something to do with "Much ADO about nothing?" :-)
I was under the impression that ADO answers were allowed only about
the obsolescent "classic ADO" as supported by various versions of
Access, not about the Microsoft's current ADO.NET software which has
succeeded classic ADO, except in Office.
Larry
Microsoft re MDAC
Introduction
This article describes the past, present, and future of Microsoft data
access technologies, including DB-Library, ESQL, DAO, Microsoft® Data
Access Components (MDAC) (including ODBC, ADO, and OLE DB), ADO.NET, and
SQL Native Client. This article identifies which technologies are being
enhanced, and which technologies and components are being deprecated or
excluded from future releases.
Microsoft Data Access Components (MDAC)
With Microsoft Data Access Components (MDAC), developers can connect to
and use data from a wide variety of relational and non-relational data
sources. You can connect to many different data sources using ActiveX®
Data Objects (ADO), Open Database Connectivity (ODBC), or OLE DB. You can
do this through providers and drivers that are either built and shipped
by Microsoft, or that are developed by various third parties.
Current MDAC Architecture
With the current MDAC architecture, client-server, n-tier, or Web browser
applications can access SQL, Semi-Structured, and Legacy Data stores.
Additionally, with MDAC (depending on requirements), these applications
have the flexibility to access the data using ADO, OLE DB, or ODBC.
Figure 1. Current MDAC architecture
For the purposes of this document, you can divide the MDAC stack into the
following components, based on technology and products:
* ADO (Including ADOMD and ADOX)
* OLE DB (including SQL Server OLE DB Provider, Oracle OLE DB
Provider, OLE DB Provider for ODBC Drivers, Data Shape Provider, and
Remote Data Provider)
* ODBC (including SQL ODBC Driver and Oracle ODBC Driver)
Current MDAC Components
These components are supported in the current release. Use these
components when you develop new applications or upgrade existing
applications.
* ADO: ActiveX Data Objects (ADO) provides a high-level programming
model that will continue to be enhanced. Although a little less
performant than coding to OLE DB or ODBC directly, ADO is straightforward
to learn and use, and can be used from script languages such as Microsoft
Visual Basic® Scripting Edition (VBScript) or Microsoft JScript®.
* ADOMD: ADO Multi-Dimensional (ADOMD) is to be used with multi-
dimensional data providers such as Microsoft OLAP Provider, also known as
Microsoft Analysis Services Provider. No major feature enhancements have
been made to it since MDAC 2.0; however, it will be available on the 64-
bit Microsoft Windows® operating system.
* ADOX: ADO Extensions for DDL and Security (ADOX) enables the
creation and modification of definitions of a database, a table, an
index, or a stored procedure. You can use ADOX with any provider. The
Microsoft Jet OLE DB Provider provides full support for ADOX, while the
Microsoft SQL OLE DB Provider provides limited support. No major
enhancements are planned for ADOX in future MDAC releases; however, it
will be available on the 64-bit Windows operating system.
* OLE DB: OLE DB is a comprehensive set of COM interfaces for
accessing a diverse range of data in a variety of data stores. OLE DB
providers exist for accessing data in databases, file systems, message
stores, directory services, workflow, and document stores. OLE DB core
services (though not every OLE DB provider) will be available on the 64-
bit Windows operating system.
* SQLOLEDB: Microsoft OLE DB Provider for SQL Server (SQLOLEDB)
supports access to Microsoft SQL Server 6.5 and later. This OLE DB
Provider will be the primary focus of future MDAC feature enhancements.
It will be available on the 64-bit Windows operating system.
* Microsoft SQL Server Network Libraries: The SQL Server Network
Libraries allow SQLOLEDB and SQLODBC to communicate with the SQL Server
database. The following SQL Server Network Libraries are currently
deprecated in MDAC releases: Banyan Vines, AppleTalk, Servernet, IPX/SPX,
Giganet, and RPC. TCP/IP, Named Pipes, and Shared Memory SQL Server
Network Libraries will continue to be enhanced and will be available on
the 64-bit Windows operating system.
* ODBC: The Microsoft Open Database Connectivity (ODBC) interface is
a C programming language interface that allows applications to access
data from a variety of Database Management Systems (DBMS). Applications
using this API are limited to accessing relational data sources only.
ODBC will be available on the 64-bit Windows operating system.
* SQLODBC: Microsoft SQL Server ODBC Driver (SQLODBC) enables access
to Microsoft SQL Server 6.5 and later. SQLODBC will be available on the
64-bit Windows operating system.
Deprecated MDAC Components
These components are still supported in the current release of MDAC, but
might be removed in future releases. Microsoft recommends that when you
develop new applications, you avoid using these components. Additionally,
when you upgrade or modify existing applications, remove any dependency
on these components.
* Jet: Starting with version 2.6, MDAC no longer contains Jet
components. In other words, MDAC 2.6, 2.7, 2.8, and all future MDAC
releases do not contain Microsoft Jet, Microsoft Jet OLE DB Provider, or
the ODBC Desktop Database Drivers.
* MSDASQL: The Microsoft OLE DB Provider for ODBC (MSDASQL) provides
ADO clients access to databases through ODBC Drivers. This has been the
default provider for ADO; however, for future releases of MDAC and the
64-bit Windows operating system, MSDASQL has been deprecated. Therefore,
to access the database from ADO, clients must use appropriate Native OLE
DB Providers, such as SQLOLEDB, to access Microsoft SQL Server. MSDASQL
will be not available on the 64-bit Windows operating system; however, it
will still be possible to use on the 64-bit Windows operating system
through the 32-bit Windows subsystem.
* MSDADS: With the Microsoft OLE DB Provider for Data Shaping
(MSDADS), you can create hierarchical relationships between keys, fields,
or rowsets in an application. No major feature enhancements have been
made since MDAC 2.1. This Provider has been deprecated in future MDAC
releases. Microsoft recommends that you use XML instead of MSDADS.
* Oracle ODBC: The Microsoft Oracle ODBC Driver (Oracle ODBC)
provides access to Oracle database servers. It provides full support for
Oracle 7. It also uses Oracle 7 emulation to provide limited support for
Oracle 8 databases. The Oracle ODBC Driver has not been tested with
Oracle 9 databases.
* MSDAORA: The Microsoft Oracle OLE DB Provider (MSDAORA) provides
access to Oracle database servers. It provides full support for Oracle 7.
It also uses Oracle 7 emulation to provide limited support for Oracle 8
databases. The Oracle OLE DB Provider has not been tested with Oracle 9
databases. A 64-bit version of this provider will not be available on the
64-bit Microsoft Windows® operating system.
* RDS: Remote Data Services (RDS) is a proprietary Microsoft
mechanism to access remote ADO Recordset objects across the Internet or
an intranet. No major feature enhancements have been made to RDS since
MDAC 2.1. This component is being deprecated. Microsoft now ships the
Microsoft SOAP Toolkit 2.0, in which applications can access remote data
by using an open, XML-based standard. Applications that use RDS should
migrate to SOAP.
* JRO: The Microsoft Jet OLE DB Provider and other related components
have been removed from the MDAC stack since MDAC 2.6. Jet Replication
Objects (JRO) is used only with Jet (Access) databases, basically to
create or compact the Jet Database and Jet Replication Management. JRO
has been deprecated and MDAC 2.7 will be its last release. It will not be
available on the 64-bit Windows operating system.
* SQL XML: SQL XML provides extensions to Microsoft OLE DB Provider
for SQL Server (SQLOLEDB) to allow clients to request Microsoft SQL
Server 2000 data through XML, and to retrieve XML streams. It was first
released with MDAC 2.6. With SQL XML Web Release 1, clients can insert,
update, and delete data in SQL Server 2000 using Updategrams and Bulk
Load. This component is not being deprecated, but it is being removed
from future MDAC releases. Current and later versions of this product are
available as Web downloads. SQL XML will be available on the 64-bit
Windows operating system.
MDAC Releases
Here is a list of the supportability scenarios of past, present, and
future MDAC releases, starting with the earliest.
* MDAC 1.5, MDAC 2.0, and MDAC 2.1: These versions of MDAC were
independent releases that were released through the Microsoft Windows NT®
Option Pack, the Microsoft Windows Platform SDK, or the MDAC Web site.
These versions of MDAC are no longer supported.
* MDAC 2.5: This version of MDAC was included with the Windows 2000
operating system. Future services packs of MDAC 2.5 will be included with
corresponding Windows 2000 service packs. Additionally, these MDAC
services packs will be released to the MDAC Web site in accordance with
the Windows 2000 service pack release schedule. You can only install this
version of MDAC on Windows NT, Windows 95, and Windows 98 platforms. You
can only install this version on Windows 2000 and Windows Millennium
Edition platforms through the operating systems or their services packs.
This version is currently supported.
* MDAC 2.6: MDAC 2.6 RTM, SP1, and SP2 were included with Microsoft
SQL Server 2000 RTM, SP1, and SP2, respectively. Additionally, these MDAC
service packs were released to the MDAC Web site in accordance with the
Microsoft SQL Server 2000 service pack release schedule. You can install
this version of MDAC and its service packs on Windows 2000, Windows
Millennium Edition, Windows NT, Windows 95, and Windows 98 platforms.
This version is no longer supported.
* MDAC 2.7: This version of MDAC is included with the Microsoft
Windows XP RTM and SP1 operating systems. You can install this version of
MDAC and its service packs on Windows 2000, Windows Millennium, Windows
NT, and Windows 98 platforms. You can only install this version on the
Windows XP platform through the operating system or its services packs.
o The 32-bit version of MDAC 2.7 has been released to the MDAC
Web site.
o The 64-bit version of MDAC 2.7 will release with the 64-bit
version of Windows XP only.
* MDAC 2.8: This version of MDAC is included with Windows Server 2003
and Windows XP SP2 and later.
o The 32-bit version of MDAC 2.8 will also be released to the
MDAC Web site at the same time Windows Server 2003 is released to the
customer.
o The 64-bit version of MDAC 2.8 will release with the 64-bit
version of Windows Server 2003 only.
SQL Native Client (SQLNCLI)
SQL Native Client (SQLNCLI) is a data access technology that is new to
Microsoft SQL Server 2005, and it is a stand alone data access
Application Programming Interface (API) that is used for both OLE DB and
ODBC. It combines the SQL OLE DB Provider and the SQL ODBC Driver into
one native dynamic link library (DLL) while also providing new
functionality that is separate and distinct from the Microsoft Data
Access Components (MDAC). SQL Native Client can be used to create new
applications or enhance existing applications that need to take advantage
of new SQL Server 2005 features such as Multiple Active Result Sets
(MARS), User-Defined Types (UDT), and XML data type support.
Note SQL Native Client is not supported with SQL Server versions
6.5 and earlier.
ADO.NET
ADO.NET is an evolutionary improvement over traditional ADO for creating
distributed, data sharing applications. It is a high-level application
programming interface that is targeted at loosely coupled, n-tier,
Internet-based applications that support disconnected access to data. It
is a core component of the Microsoft .NET Framework.
Figure 2. ADO.NET architecture
ADO.NET provides .NET-managed providers for connected access, and
DataSets that read and write in XML for disconnected management of
retrieved data and user interaction. The following data providers are
available for ADO.NET:
* Microsoft SQL .NET Data Provider: This provider allows .NET
applications to directly access a Microsoft SQL Server database.
* Microsoft OLE DB .NET Data Provider: This provider allows .NET
applications to access databases using their native OLE DB Providers.
* Microsoft ODBC .NET Data Provider: This provider allows .NET
applications to access databases by using their ODBC drivers.
* Microsoft Oracle .NET Data Provider: This provider allows .NET
applications to access an Oracle database.
The DataSet reads and writes XML and the XMLDataDocument integrates
relational and XML views.
Obsolete Data Access Technologies
Obsolete technologies are technologies that have not been enhanced or
updated in several product releases and that will be excluded from future
product releases. Do not use these technologies when you write new
applications. When you modify existing applications that are written
using these technologies, consider migrating those applications to
ADO.NET.
The following components are considered obsolete:
* DB-Library: This is a SQL Server-specific programming model that
includes C APIs. There have been no feature enhancements to the DB-
Library since SQL Server 6.5. Its final release was with SQL Server 2000
and it will not be ported to the 64-bit Windows operating system.
* Embedded SQL (E-SQL): This is a SQL Server-specific programming
model that enables Transact-SQL statements to be embedded in Visual C
code. No feature enhancements have been made to the E-SQL since SQL
Server 6.5. Its final release was with SQL Server 2000 and it will not be
ported to the 64-bit Windows operating system.
* Data Access Objects (DAO): DAO provides access to JET (Access)
databases. This API can be used from Microsoft Visual Basic®, Microsoft
Visual C++®, and scripting languages. It was included with Microsoft
Office 2000 and Office XP. DAO 3.6 is the final version of this
technology. It will not be available on the 64-bit Windows operating
system.
* Remote Data Objects (RDO): RDO was specifically designed to access
remote ODBC relational data sources, and made it easier to use ODBC
without complex application code. It was included with Microsoft Visual
Basic versions 4, 5, and 6. RDO version 2.0 was the final version of this
technology.
--
Lyle Fairfield