Microsoft Access

Microsoft Access

Microsoft Office Access Icon
Microsoft Office Access 2010 running on Windows 7
Developer(s)	Microsoft Corporation
Initial release	1.0 / November 1992 (1992-11)
Stable release	2010 (14.0) / April 28, 2010 (2010-04-28)
Preview release	2013 Beta (15.0.4128.1014) / July 16, 2012 (2012-07-16)
Operating system	Microsoft Windows
Type	DBMS
License	Proprietary commercial software
Website	office.microsoft.com/access

Microsoft Access, also known as Microsoft Office Access, is a database management system from Microsoft that combines the relational Microsoft Jet Database Engine with a graphical user interface and software-development tools. It is a member of the Microsoft Office suite of applications, included in the Professional and higher editions or sold separately. On May 12, 2010, the current version of Microsoft Access 2010 was released by Microsoft in Office 2010; Microsoft Office Access 2007 was the prior version.

Microsoft Access stores data in its own format based on the Access Jet Database Engine. It can also import or link directly to data stored in other applications and databases.

Software developers and data architects can use Microsoft Access to develop application software, and "power users" can use it to build software applications. Like other Office applications, Access is supported by Visual Basic for Applications, an object-oriented programming language that can reference a variety of objects including DAO (Data Access Objects), ActiveX Data Objects, and many other ActiveX components. Visual objects used in forms and reports expose their methods and properties in the VBA programming environment, and VBA code modules may declare and call Windows operating-system functions.

History

Project Omega

Microsoft's first attempt to sell a relational database product was during the mid 1980s, when Microsoft obtained license to sell R:Base. In the late 1980s Microsoft developed its own solution codenamed Omega. It was confirmed in 1988 that a database product for Windows and OS/2 was in development. It was going to include "EB" Embedded Basic language, which was going to be the language for writing macros in all Microsoft applications, but the unification of macro languages did not happen until the introduction of VBA. Omega was also expected to provide a front end to the Microsoft SQL Server. The application was very resource-hungry, and there were reports that it was working slowly on the 386 processors that were available at the time. It was scheduled to be released in the 1st quarter of 1990, but in 1989 the development of the product was reset and it was rescheduled to be delivered no sooner than in January 1991. Parts of the project were later used for other Microsoft projects: Cirrus (codename for Access) and Thunder (codename for Visual Basic, where the Embedded Basic engine was used). After Access's premiere, the Omega project was demonstrated in 1992 to several journalists and included features that were not available in Access.

Project Cirrus

After the Omega project was scrapped, some of its developers were assigned to the Cirrus project (most were assigned to the team which created Visual Basic). Its goal was to create a competitor for applications like Paradox or dBase that would work on Windows. After Microsoft acquired FoxPro, there were rumors that the Microsoft project might get replaced with it, but the company decided to develop them in parallel. It was assumed that the project would make use of Extensible Storage Engine (Jet Blue) but, in the end, only support for Microsoft Jet Database Engine (Jet Red) was provided. The project used some of the code from both the Omega project and a pre-release version of Visual Basic. In July 1992, betas of Cirrus shipped to developers and the name Access became the official name of the product.

Timeline

1992: Microsoft released Access version 1.0 on 13 November 1992, and an Access 1.1 release in May 1993 to improve compatibility with other Microsoft products and to include the Access Basic programming language.

1993: Microsoft specified the minimum hardware requirements for Access v2.0 as: Microsoft Windows v3.1 with 4 MB of RAM required, 6 MB RAM recommended; 8 MB of available hard disk space required, 14 MB hard disk space recommended. The product shipped on seven 1.44 MB diskettes. The manual shows a 1993 copyright date.

Originally, the software worked well with relatively small databases but testing showed that some circumstances caused data corruption. For example, file sizes over 10 MB proved problematic (note that most hard disks held less than 500 MB at the time this was in wide use), and the Getting Started manual warns about a number of circumstances where obsolete device drivers or incorrect configurations can cause data loss. With the phasing out of Windows 95, 98 and ME, improved network reliability, and Microsoft having released 8 service packs for the Jet Database Engine, the reliability of Access databases has improved and it supports both more data and a larger number of users.

With Office 95, Microsoft Access 7.0 (a.k.a. "Access 95") became part of the Microsoft Office Professional Suite, joining Microsoft Excel, Word, and PowerPoint and transitioning from Access Basic to Visual Basic for Applications (VBA). Since then, Microsoft has released new versions of Microsoft Access with each release of Microsoft Office. This includes Access 97 (version 8.0), Access 2000 (version 9.0), Access 2002 (version 10.0), Access 2003 (version 11.5), Access 2007 (version 12.0), and Access 2010 (version 14.0).

Versions 3.0 and 3.5 of Microsoft Jet database engine (used by Access 7.0 and the later-released Access 97 respectively) had a critical issue which made these versions of Access unusable on a computer with more than 1 GB of memory. While Microsoft fixed this problem for Jet 3.5/Access 97 post-release, it never fixed the issue with Jet 3.0/Access 95.

The native Access database format (the Jet MDB Database) has also evolved over the years. Formats include Access 1.0, 1.1, 2.0, 7.0, 97, 2000, 2002, 2007, and 2010. The most significant transition was from the Access 97 to the Access 2000 format; which is not backward compatible with earlier versions of Access. As of 2011 all newer versions of Access support the Access 2000 format. New features were added to the Access 2002 format which can be used by Access 2002, 2003, 2007, and 2010.

MS Access 2007 introduced a new database format: ACCDB. ACCDB supports complex data types such as multivalue and attachment fields. These new field types are essentially recordsets in fields and allow the storage of multiple values in one field. With Access 2010, a new version of the ACCDB format supports hosting on a SharePoint 2010 server for exposure to the web.

Prior to the introduction of Access, Borland (with Paradox and dBase) and Fox (with FoxPro) dominated the desktop database market. Microsoft Access was the first mass-market database program for Windows. With Microsoft's purchase of FoxPro in 1992 and the incorporation of Fox's Rushmore query optimization routines into Access, Microsoft Access quickly became the dominant database for Windows - effectively eliminating the competition which failed to transition from the MS-DOS world.

Access's initial codename was Cirrus; the forms engine was called Ruby. This was before Visual Basic - Bill Gates saw the prototypes and decided that the BASIC language component should be co-developed as a separate expandable application, a project called Thunder. The two projects were developed separately.

Access was also the name of a communications program from Microsoft, meant to compete with ProComm and other programs. This proved a failure and was dropped. Years later, Microsoft reused the name for its database software.

Uses

In addition to using its own database storage file, Microsoft Access may also be used as the 'front-end' with other products as the 'back-end' tables, such as Microsoft SQL Server and non-Microsoft products such as Oracle and Sybase. Multiple backend sources can be used by a Microsoft Access Jet Database (accdb and mdb formats). Similarly, some applications will only use the Microsoft Access tables and use another product as a front-end, such as Visual Basic or ASP.NET. Microsoft Access may be only part of the solution in more complex applications, where it may be integrated with other technologies such as Microsoft Excel, Microsoft Outlook or ActiveX Data Objects.

Access tables support a variety of standard field types, indices, and referential integrity. Access also includes a query interface, forms to display and enter data, and reports for printing. The underlying Jet database, which contains these objects, is multiuser-aware and handles record-locking and referential integrity including cascading updates and deletes.

Repetitive tasks can be automated through macros with point-and-click options. It is also easy to place a database on a network and have multiple users share and update data without overwriting each other's work. Data is locked at the record level which is significantly different from Excel which locks the entire spreadsheet.

There are template databases within the program and for download from their website. These options are available upon starting Access and allow users to enhance a database with predefined tables, queries, forms, reports, and macros. Templates do not include VBA code.

Programmers can create solutions using the programming language Visual Basic for Applications (VBA), which is similar to Visual Basic 6.0 (VB6) and used throughout the Microsoft Office programs such as Excel, Word, Outlook and PowerPoint. Most VB6 code, including the use of Windows API calls, can be used in VBA. Power users and developers can extend basic end-user solutions to a professional solution with advanced automation, data validation, error trapping, and multi-user support.

The number of simultaneous users that can be supported depends on the amount of data, the tasks being performed, level of use, and application design. Generally accepted limits are solutions with 1 GB or less of data (Access supports up to 2 GB) and performs quite well with 100 or fewer simultaneous connections (255 concurrent users are supported). This capability is often a good fit for department solutions. If using an Access database solution in a multi-user scenario, the application should be "split". This means that the tables are in one file called the back end (typically stored on a shared network folder) and the application components (forms, reports, queries, code, macros, linked tables) are in another file called the front end. The linked tables in the front end point to the back end file. Each user of the Access application would then receive his or her own copy of the front end file.

Applications that run complex queries or analysis across large datasets would naturally require greater bandwidth and memory. Microsoft Access is designed to scale to support more data and users by linking to multiple Access databases or using a back-end database like Microsoft SQL Server. With the latter design, the amount of data and users can scale to enterprise-level solutions.

Microsoft Access's role in web development prior to version 2010 is limited. User interface features of Access, such as forms and reports, only work in Windows. In versions 2000 through 2003 an Access object type called Data Access Pages created publishable web pages. Data Access Pages are no longer supported. The Microsoft Jet Database Engine, core to Access, can be accessed through technologies such as ODBC or OLE DB. The data (i.e., tables and queries) can be accessed by web-based applications developed in ASP.NET, PHP, or Java.

Access 2010 allows databases to be published to SharePoint 2010 web sites running Access Services. These web-based forms and reports run in any modern web browser. The resulting web forms and reports, when accessed via a web browser, don't require any add-ins or extensions (e.g. ActiveX, Silverlight).

A compiled version of an Access database (File extensions: .MDE /ACCDE or .ADE; ACCDE only works with Access 2007 or later) can be created to prevent user from accessing the design surfaces to modify module code, forms, and reports. An MDE/ACCDE file is a Microsoft Access database file with all modules compiled and all editable source code removed. An ADE file is an Access project file with all modules compiled and all editable source code removed. Both the .MDE/ACCDE and .ADE versions of an Access database are used when end-user modifications are not allowed or when the application’s source code should be kept confidential.

Microsoft offers a runtime version of Microsoft Access 2007 for download. This allows people to create Access solutions and distribute it for use by non-Microsoft Access owners (similar to the way DLLs or EXEs are distributed). Unlike the regular version of Access, the runtime version allows users to use the Access application but they cannot use its design surfaces.

Microsoft also offers developer extensions for download to help distribute Access applications, create database templates, and integrate source code control with Microsoft Visual SourceSafe.

Features

Users can create tables, queries, forms and reports, and connect them together with macros. Advanced users can use VBA to write rich solutions with advanced data manipulation and user control. Access also has report creation features that can work with any data source that Access can "access".

The original concept of Access was for end users to be able to "access" data from any source. Other features include: the import and export of data to many formats including Excel, Outlook, ASCII, dBase, Paradox, FoxPro, SQL Server, Oracle, ODBC, etc. It also has the ability to link to data in its existing location and use it for viewing, querying, editing, and reporting. This allows the existing data to change while ensuring that Access uses the latest data. It can perform heterogeneous joins between data sets stored across different platforms. Access is often used by people downloading data from enterprise level databases for manipulation, analysis, and reporting locally.

There is also the Jet Database format (MDB or ACCDB in Access 2007) which can contain the application and data in one file. This makes it very convenient to distribute the entire application to another user, who can run it in disconnected environments.

One of the benefits of Access from a programmer's perspective is its relative compatibility with SQL (structured query language) — queries can be viewed graphically or edited as SQL statements, and SQL statements can be used directly in Macros and VBA Modules to manipulate Access tables. Users can mix and use both VBA and "Macros" for programming forms and logic and offers object-oriented possibilities. VBA can also be included in queries.

Microsoft Access offers parameterized queries. These queries and Access tables can be referenced from other programs like VB6 and .NET through DAO or ADO. From Microsoft Access, VBA can reference parameterized stored procedures via ADO.

The desktop editions of Microsoft SQL Server can be used with Access as an alternative to the Jet Database Engine. This support started with MSDE (Microsoft SQL Server Desktop Engine), a scaled down version of Microsoft SQL Server 2000, and continues with the SQL Server Express versions of SQL Server 2005 and 2008.

Microsoft Access is a file server-based database. Unlike client–server relational database management systems (RDBMS), Microsoft Access does not implement database triggers, stored procedures, or transaction logging. Access 2010 includes table-level triggers and stored procedures built into the ACE data engine. Thus a Client-server database system is not a requirement for using stored procedures or table triggers with Access 2010. Tables, queries, Forms, reports and Macros can now be developed specifically for web base application in Access 2010. Integration with Microsoft SharePoint 2010 is also highly improved.

Access Services and Web database

See also: Web form and web database

ASP.NET web forms can query an MS Access database, retrieve records and display them on the browser.

SharePoint Server 2010 via Access Services allows for Access 2010 databases to be published to SharePoint, thus enabling multiple users to interact with the database application from any standards-compliant Web browser. Access Web databases published to SharePoint Server can use standard objects such as tables, queries, forms, macros, and reports. Access Services stores those objects in SharePoint.

Import or Link sources

Microsoft Access can also import or link directly to data stored in other applications and databases. Microsoft Office Access 2007 and newer can import from or link to:

• Microsoft Access
• Excel
• SharePoint lists
• text
• XML
• Outlook
• HTML
• dBase
• Paradox (with Access 2007; dropped in Access 2010)
• Lotus 1-2-3
• ODBC-compliant data containers, including:
  • Microsoft SQL Server
  • Oracle
  • MySQL
  • PostgreSQL

Development

Access stores all database tables, queries, forms, reports, macros, and modules in the Access Jet database as a single file.

For query development, Access offers a "Query Designer", a graphical user interface that allows users to build queries without knowledge of structured query language. In the Query Designer, users can "show" the datasources of the query (which can be tables or queries) and select the fields they want returned by clicking and dragging them into the grid. One can set up joins by clicking and dragging fields in tables to fields in other tables. Access allows users to view and manipulate the SQL code if desired. Any Access table, including linked tables from different data sources, can be used in a query.

Access also supports the creation of "pass-through queries". These snippets of SQL code can address external data sources through the use of ODBC connections on the local machine. This enables users to interact with data stored outside the Access program without using linked tables or Jet. Users construct the pass-through queries using the SQL syntax supported by the external data source.

When developing reports that are linked to queries placing or moving items in the design view of the report, Access runs the linked query in the background on any placement or movement of an item in that Report. If the report is linked to a query that takes a long time to return records this means having to wait until the query has run before you can add/edit or move the next item in the report (this feature cannot be turned off).

Non-programmers can use the macro feature to automate simple tasks through a series of drop-down selections. Macros allow users to easily chain commands together such as running queries, importing or exporting data, opening and closing forms, previewing and printing reports, etc. Macros support basic logic (IF-conditions) and the ability to call other macros. Macros can also contain sub-macros which are similar to subroutines. In Access 2007 enhanced macros with the inclusion of error-handling and of support for temporary variables. Access 2007 also introduced embedded macros that are essentially properties of an object's event. This eliminated the need to store macros as individual objects. Macros however, are limited in their functionality by a lack of programming loops and of advanced coding logic. Most professional Access developers use the VBA programming language for a richer and more powerful development environment.

The programming language available in Access is, as in other products of the Microsoft Office suite, Microsoft Visual Basic for Applications, which is nearly identical to Visual Basic 6.0 (VB6). VBA code can be stored in modules and code behind forms and reports. Modules can also be classes.

To manipulate data in tables and queries in VBA, Microsoft provides two database access libraries of COM components:

1. Data Access Objects (DAO) (32-bit only), which is included in Access and Windows and evolved to ACE in Microsoft Access 2007 for the ACCDE database format
2. ActiveX Data Objects ActiveX Data Objects (ADO) (both 32-bit and 64-bit versions)

Beside DAO and ADO, developers can also use OLE DB and ODBC for developing native C/C++ programs for Access. For ADPs and the direct manipulation of SQL Server data, ADO is required. DAO is most appropriate for managing data in Access/Jet databases, and the only way to manipulate the complex field types in ACCDB tables.

In the database container or navigation pane of Access 2007, the system automatically categorizes each object by type. Many Access developers use the Leszynski naming convention, though this is not universal; it is a programming convention, not a DBMS-enforced rule. It is particularly helpful in VBA where references to object names may not indicate its data type (e.g. tbl for tables, qry for queries).

Developers deploy Microsoft Access most often for individual and workgroup projects (the Access 97 speed characterization was done for 32 users). Since Access 97, and with Access 2003 and 2007, Microsoft Access and hardware have evolved significantly. Databases under 1 GB in size (which can now fit entirely in RAM) and 50 simultaneous users are well within the capabilities of Microsoft Access. Of course, performance depends on the database design and tasks. Disk-intensive work such as complex searching and querying take the most time.

As data from a Microsoft Access database can be cached in RAM, processing speed may substantially improve when there is only a single user or if the data are not changing. In the past, the effect of packet latency on the record-locking system caused Access databases to run slowly on a Virtual Private Network (VPN) or a Wide Area Network (WAN) against a Jet database. As of 2010 broadband connections have mitigated this issue. Performance can also be enhanced if a continuous connection is maintained to the back-end database throughout the session rather than opening and closing it for each table access. If Access Database performance over VPN or WAN suffers, then a client using Remote Desktop Protocol (such as Microsoft Terminal Services) can provide an effective solution. Access databases linked to SQL Server or to Access Data Projects work well over VPNs and WANs.

In July 2011, Microsoft acknowledged an intermittent query performance problem with all versions of Access and Windows 7 and Windows Server 2008 R2 due to the nature of resource management being vastly different in newer operating systems. This issue affects query performance severely on both Access 2003 and earlier with the Jet Database Engine code as well as Access 2007 and later with the Access Database Engine (ACE). Microsoft has issued hotfixes KB2553029 for Access 2007 and KB2553116 for Access 2010, but will not fix the issue with Jet 4.0 as it is out of mainstream support.

In previous versions of Microsoft Access the ability to distribute applications required the purchase of the Developer Toolkit, from Access 2010 the Runtime Only version is offered as a free download, making the distribution of free applications possible on Windows 7.

Split Database Architecture

Microsoft Access applications can adopt a split-database architecture. The database can be divided into a front-end database that contains the application objects (queries, forms, reports, macros, and modules), and is linked to tables stored in a back-end shared database containing the data. The "back-end" database can be stored in a location shared by many users, such as a file server. The "front-end" database is distributed to each user's desktop and linked to the shared database. Using this design, each user has a copy of Microsoft Access installed on their machine along with their application database. This reduces network traffic since the application is not retrieved for each use, and allows the front-end database to contain tables with data that is private to each user for storing settings or temporary data. This split-database design also allows development of the application independent of the data. When a new version is ready, the front-end database is replaced without impacting the data database. Microsoft Access has two built-in utilities, Database Splitter and Linked Table Manager, to facilitate this architecture.

Linked tables in Access use absolute paths rather than relative paths, so the development environment either has to have the same path as the production environment or a "dynamic-linker" routine can be written in VBA.

For very large Access databases, this may have performance issues and a SQL backend should be considered in these circumstances. This is less of an issue if the entire database can fit in the PC's RAM since Access caches data and indexes.

Access to SQL Server Upsizing (Upgrading) (SQL as a backend)

To scale Access applications to enterprise or web solutions, one possible technique involves migrating to Microsoft SQL Server or equivalent server database. A client–server design significantly reduces maintenance and increases security, availability, stability, and transaction logging.

Access includes an Upsizing Wizard that allows users to upgrade their databases to Microsoft SQL Server, an ODBC client–server database. An additional solution, the SQL Server Migration Assistant for Access (SSMA), is also available for download from Microsoft.

A variety of upgrading options are available. After migrating the data and queries to SQL Server, the MDB/ACCDB Access database can be linked to the database. This is the easiest migration and most appropriate if the user does not have rights to create objects such as stored procedures on SQL Server. Retrieving data from linked tables is optimized to just the records needed, but this scenario operates less efficiently for multi-table joins that may require copying the whole table across the network.

Access databases can also be converted to Access Data Projects (ADP) which are tied directly to one SQL Server database. ADP's support the ability to directly create and modify SQL Server objects such as tables, views, stored procedures, and SQL Server constraints. The views and stored procedures can significantly reduce the network traffic for multi-table joins. Fortunately, SQL Server supports temporary tables and links to other data sources beyond the single SQL Server database.

Finally, some Access databases are completely replaced by another technology such as ASP.NET or Java once the data is converted.

In many cases, developers build web interfaces using ASP.NET, while keeping administrative or reporting features that don't need to be distributed to everyone and/or don't change often in Access for information workers to maintain.

While all Access data can migrate to SQL Server, some queries cannot migrate successfully. In some situations, you may need to translate VBA functions and user defined functions into T–SQL or .NET functions / procedures. Crosstab queries can be migrated to SQL Server using the PIVOT command.

Microsoft Access has a reputation among IT professionals as not being as economical on server resources when running large query transactions, especially if users force-terminate the application on the client side. Transactions that were running might still be running on the SQL server unbeknownst to the end-user.

Protection

Microsoft Access offers several ways to secure the application while allowing users to remain productive.

The most basic is a database password. Once entered, the user has full control of all the database objects. This is a relatively weak form of protection which can be easily cracked.

A higher level of protection is the use of workgroup security requiring a user name and password. Users and groups can be specified along with their rights at the object type or individual object level. This can be used to specify people with read-only or data entry rights but may be challenging to specify. A separate workgroup security file contains the settings which can be used to manage multiple databases. Workgroup security is not supported in the Access 2007 and Access 2010 ACCDB database format, although Access 2007 and Access 2010 still support it for MDB databases.

Databases can also be encrypted. The ACCDB format offers significantly advanced encryption from previous versions.

Additionally, if the database design needs to be secured to prevent changes, Access databases can be locked/protected (and the source code compiled) by converting the database to a .MDE file. All changes to the VBA project (modules, forms, or reports) need to be made to the original MDB and then reconverted to MDE. In Access 2007 and Access 2010, the ACCDB database is converted to an ACCDE file. Some tools are available for unlocking and "decompiling", although certain elements including original VBA comments and formatting are normally irretrievable.

File extensions

Microsoft Access saves information under the following file formats:

File format	Extension
Protected Access Project	.ade
Access Project	.adp
Access Blank Project Template	.adn
Access Database (2007)	.accdb
Access Database Runtime (2007)	.accdr
Access Database Template (2007)	.accdt
Access Database (2003 and earlier)	.mdb
Access Database, used for addins (2,95,97), previously used for workgroups (2).	.mda
Access Blank Database Template (2003 and earlier)	.mdn
Access Add-in Data (2003 and earlier)	.mdt
Access Workgroup, database for user-level security.	.mdw
Access (SQL Server) detached database (2000)	.mdf
Protected Access Database, with compiled VBA (2003 and earlier)	.mde
Protected Access Database, with compiled VBA (2007)	.accde
Windows Shortcut: Access Macro	.mam
Windows Shortcut: Access Query	.maq
Windows Shortcut: Access Report	.mar
Windows Shortcut: Access Table	.mat
Windows Shortcut: Access Form	.maf
Access lock files	.ldb

Versions

Version	Version number	Release Date	Jet version	Supported OS	Office suite version
Access 1.1	1	1992	1.1	Windows 3.0
Access 2.0	2.0	1993	2.0	Windows 3.1x	Office 4.3 Pro
Access for Windows 95	7.0	Aug. 24, 1995	3.0	Windows 95	Office 95 Professional
Access 97	8.0	Jan. 16, 1997	3.5	Windows 9x, NT 3.51/4.0	Office 97 Professional and Developer
Access 2000	9.0	June 7, 1999	4.0 SP1	Windows 9x, NT 4.0, 2000, XP	Office 2000 Professional, Premium and Developer
Access 2002	10	May 31, 2001	4.0 SP1	Windows 98, Me, 2000, XP	Office XP Professional and Developer
Access 2003	11	Nov. 27, 2003	4.0 SP1	Windows 2000, XP, XP Professional x64, Vista	Office 2003 Professional and Professional Enterprise
Access 2007	12	Jan. 27, 2007	12	Windows XP SP2, XP Professional x64, Vista	Office 2007 Professional, Professional Plus, Ultimate and Enterprise
Access 2010	14	July 15, 2010	14	Windows XP SP3, Vista, Windows 7	Office 2010 Professional, Professional Academic and Professional Plus

Note: There are no Access versions between 2.0 and 7.0 because the Windows 95 version was launched with Word 7. All of the Office 95 products have OLE 2 capabilities, and Access 7 shows that it was compatible with Word 7.

Note: Version number 13 was skipped due to superstition.

See also

• Comparison of relational database management systems
• Form (web)
• MDB Tools
• Kexi

External links

• Access Team Blog
• Microsoft Access Home Page
• Office 2010 product guide
• Microsoft Access Newsgroups
• Microsoft Access 3rd Party Tools
• FAQ site about Microsoft Access
• Microsoft Access 2010 Error Number and Error Description Reference

This article is based on material taken from the Free On-line Dictionary of Computing prior to 1 November 2008 and incorporated under the "relicensing" terms of the GFDL, version 1.3 or later.