Microsoft Access
From Wikipedia, the free encyclopedia
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Microsoft Office Access 2013 running on Windows 8
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| Developer(s) | Microsoft Corporation |
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| Initial release | November 1992 |
| Stable release |
2016 (16.0.4229.1024) / September 22, 2015
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| Development status | Active |
| Operating system | Microsoft Windows |
| Type | DBMS |
| License | Trialware |
| Website | office |
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.[1]
Software developers, data architects and power users can use Microsoft Access to develop application software. Like other Microsoft Office applications, Access is supported by Visual Basic for Applications (VBA), an object-based 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 operations.
Contents
History
Project Omega
Microsoft's first attempt to sell a relational database product was during the mid 1980s, when Microsoft obtained the license to sell R:Base.[2] In the late 1980s Microsoft developed its own solution codenamed Omega.[3] It was confirmed in 1988 that a database product for Windows and OS/2 was in development.[4][5] It was going to include the "EB" Embedded Basic language,[3] which was going to be the language for writing macros in all Microsoft applications,[6] but the unification of macro languages did not happen until the introduction of Visual Basic for Applications (VBA). Omega was also expected to provide a front end to the Microsoft SQL Server.[7] 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.[8] It was scheduled to be released in the 1st quarter of 1990,[9] but in 1989 the development of the product was reset[2][10] and it was rescheduled to be delivered no sooner than in January 1991.[11] 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).[2][3] After Access's premiere, the Omega project was demonstrated in 1992 to several journalists and included features that were not available in Access.[12]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).[2] Its goal was to create a competitor for applications like Paradox or dBase that would work on Windows.[13] After Microsoft acquired FoxPro, there were rumors that the Microsoft project might get replaced with it,[14] but the company decided to develop them in parallel. It was assumed that the project would make use of Extensible Storage Engine (Jet Blue)[15] 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.[3] In July 1992, betas of Cirrus shipped to developers[16] and the name Access became the official name of the product.[17]Timeline
1992: Microsoft released Access version 1.0 on November 13, 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.1994: 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 1994 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[when?] 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 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), Access 2010 (version 14.0), and Access 2013 (version 15.0).
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.[18] 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.
Microsoft Access 2000 increased the maximum database size to 2GB from 1GB in Access 97.
Microsoft Access 2007 introduced a new database format: ACCDB. It supports links to SharePoint lists and 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 or files in one field. Microsoft Access 2007 also introduced File Attachment field, which stored data more efficiently than the OLE (Object Linking and Embedding) field.
Microsoft Access 2010 introduced a new version of the ACCDB format supported hosting Access Web solutions on a SharePoint 2010 server. For the first time, this allowed Access solutions to be run without having to install Access on their PC and was the first support of Mac users. Any user on the SharePoint site with sufficient rights could use the Access Web solution. A copy of Access was still required for the developer to create the Access Web solution, and the desktop version of Access remained part of Access 2010. The Access Web solutions were not the same as the desktop solutions. Automation was only through the macro language (not VBA) which Access automatically converted to JavaScript. The data was no longer in an Access database but SharePoint lists. An Access desktop database could link to the SharePoint data, so hybrid applications were possible so that SharePoint users needing basic views and edits could be supported while the more sophisticated, traditional solutions could remain in the desktop Access database.
Microsoft Access 2013 offers traditional Access desktop solutions plus a significantly updated SharePoint 2013 web solution.[19] The Access Web model in Access 2010 was replaced by a new architecture that stores its data in actual SQL Server databases. Unlike SharePoint lists, this offers true relational database design with referential integrity, scalability, extensibility and performance one would expect from SQL Server.[20] The database solutions that can be created on SharePoint 2013 offer a modern user interface designed to display multiple levels of relationships that can be viewed and edited, along with resizing for different devices and support for touch. The Access 2013 desktop is similar to Access 2010 but several features were discontinued including support for Access Data Projects (ADPs), pivot tables, pivot charts, Access data collections, source code control, replication, and other legacy features.[21] Access desktop database maximum size remained 2GB (as it has been since the 2000 version).
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.[22]
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.[23] Years later, Microsoft reused the name for its database software.
Uses
In addition to using its own database storage file, Microsoft Access also may be used as the 'front-end' of a program while other products act 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 such as Visual Basic, ASP.NET, or Visual Studio .NET will use the Microsoft Access database format for its tables and queries. Microsoft Access may also be part of a more complex solution, where it may be integrated with other technologies such as Microsoft Excel, Microsoft Outlook, Microsoft Word, Microsoft PowerPoint and ActiveX controls.Access tables support a variety of standard field types, indices, and referential integrity including cascading updates and deletes. 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 multi-user and handles record-locking.
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 Microsoft's website. These options are available upon starting Access and allow users to enhance a database with predefined tables, queries, forms, reports, and macros. Database templates support VBA code but Microsoft's templates do not include VBA code.
Programmers can create solutions using 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. With the use of Microsoft's Terminal Services and Remote Desktop Application in Windows Server 2008 R2, organizations can host Access applications so they can be run over the web.[24] This technique does not scale the way a web application would but is appropriate for a limited number of users depending on the configuration of the host.
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).
Access 2013 can create web applications directly in SharePoint 2013 sites running Access Services. Access 2013 web solutions store its data in an underlying SQL Server database which is much more scalable and robust than the Access 2010 version which used SharePoint lists to store its data.
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 or ADE file is a Microsoft Access database file with all modules compiled and all editable source code removed. Both the .MDE 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 also offers developer extensions for download to help distribute Access 2007 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 and Oracle. 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.
The 2013 edition of Microsoft Access introduced a mostly flat design and the ability to install apps from the Office Store, but it did not introduce new features. The theme was partially updated again for 2016, but no dark theme was created for Access.
Access Services and Web database
See also: Web form
ASP.NET web forms can query a Microsoft 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.[25]
Access 2013 offers the ability to publish Access web solutions on SharePoint 2013. Rather than using SharePoint lists as its data source, Access 2013 uses an actual SQL Server database hosted by SharePoint or SQL Azure. This offers a true relational database with referential integrity, scalability, maintainability, and extensibility compared to the SharePoint views Access 2010 used. The macro language is enhanced to support more sophisticated programming logic and database level automation.[
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