dBASE III

The correct title of this article is dBASE. The initial letter is capitalized because of technical restrictions.

dBASE was the first widely used database management system or DBMS for microcomputers, published by Ashton-Tate for CP/M, and later on the Apple II, Apple Macintosh and IBM PC under DOS where it became one of the best-selling software titles for a number of years. dBASE was never able to transition successfully to Microsoft Windows and was eventually displaced by newer products like Paradox, Clipper, FoxPro, and Microsoft Access. dBASE was sold to Borland in 1991, which sold the rights to the product line in 1999 to the newly-formed dBASE Inc. Image File history File links Dbaseshot. ... Image File history File links Dbaseshot. ... To meet Wikipedias quality standards, this article or section may require cleanup. ... The Commodore 64 was one of the most popular microcomputers of its era, and is the best selling home computer of all time. ... Ashton-Tate (Ashton-Tate Corporation) was a US based software company best known for developing the popular dBASE database application. ... CP/M is an operating system originally created for Intel 8080/85 and Zilog Z80 based microcomputers by Gary Kildall of Digital Research, Inc. ... The Apple II was one of the most popular personal computers of the 1980s. ... The first Macintosh computer, introduced in 1984, upgraded to a 512K Fat Mac. The Macintosh, or Mac, is a line of personal computers designed, developed, manufactured, and marketed by Apple Computer. ... IBM PC (IBM 5150) with keyboard and green screen monochrome monitor (IBM 5151), running MS-DOS 5. ... ‹ The template below has been proposed for deletion. ... Microsoft Windows is the worlds largest operating system for use on personal computers. ... Paradox is a relational database management software originally released from Ansa-Software. ... Clipper is a computer programming language that is used to create software programs that originally operated primarily under DOS. Although it is a powerful general-purpose programming language, it was primarily used to create database/business programs. ... Visual FoxPro is a data-centric object-oriented and procedural programming language by Microsoft. ... Microsoft Access is a relational database management system from Microsoft, packaged with Microsoft Office Professional which combines the relational Microsoft Jet Database Engine with a graphical user interface. ... Borland Software Corporation is a software company NASDAQ: BORL, founded by Philippe Kahn located in California, best known for its relentless focus on software craftsmanship and intellectual property rights as well as its Turbo Pascal programming tool that has evolved into todays Delphi programming language and now its ALM... 1991 (MCMXCI) was a common year starting on Tuesday of the Gregorian calendar. ... 1999 (MCMXCIX) was a common year starting on Friday, and was designated the International Year of Older Persons by the United Nations. ...

Starting in the mid 1980s many other companies produced their own dialects or variations on the product and language. These included FoxPro (now Visual FoxPro), Arago, Force, Recital, dbFast, dbXL, Quicksilver, Clipper, Xbase++, FlagShip, and Harbour. Together these are informally referred to as xBase or XBase. Visual FoxPro is a data-centric object-oriented and procedural programming language by Microsoft. ... Visual FoxPro is a data-centric object-oriented and procedural programming language produced by Microsoft. ... Clipper is a computer programming language that is used to create software programs that originally operated primarily under DOS. Although it is a powerful general-purpose programming language, it was primarily used to create database/business programs. ... xBase is the generic term for all programming languages that derive from the original dBase (Ashton-Tate) programming language. ...

dBASE's underlying file format, the .dbf file, is widely used in many other applications needing a simple format to store structured data.

dBASE was licensed to users for a term of fifty years in the unlikely event that a user would use their copy of dBASE for a long period of time.

Origins

The original developer of dBASE was Wayne Ratliff[1]. In 1978, while at the Jet Propulsion Laboratory, Ratliff wrote a database program in assembly language for CP/M based microcomputers to help him win the football pool at the office. He based it on Jeb Long's JPLDIS (Jet Propulsion Laboratory Display Information System) and called it "Vulcan," after Mr. Spock of Star Trek. According to Ratliff, the language in JPLDIS was a simple, command-driven language intended for interactive use on printing terminals. There is some evidence that JPLDIS was influenced by a legacy mainframe database product called RETRIEVE. Please wikify (format) this article as suggested in the Guide to layout and the Manual of Style. ... 1978 (MCMLXXVIII) was a common year starting on Sunday (the link is to a full 1978 calendar). ... The NASA Jet Propulsion Laboratory (JPL), in La Cañada Flintridge, near Los Angeles, California, USA, builds and operates unmanned spacecraft for the National Aeronautics and Space Administration (NASA). ... It has been suggested that Assembler be merged into this article or section. ... In the mid-1960s, the Jet Propulsion Laboratory (JPL) of the California Institute of Technology (CalTech) was using an IBM product named RETRIEVE. For reasons lost to history, in the late 60’s Jeb Long, a new programmer at JPL, was assigned the task of writing a program which... Spock, commonly called Mr. ... Star Trek collectively refers to an American science-fiction franchise spanning six unique television series (which comprise 726 episodes) and ten feature films, in addition to hundreds of novels, computer and video games, fan stories, and other works of fiction — all of which are set within the same fictional universe...

In late 1980, George Tate, of Ashton-Tate, entered into a marketing agreement with Ratliff. Vulcan was renamed to dBASE, and the software quickly became a huge success. 1980 (MCMLXXX) was a leap year starting on Tuesday. ...

dBASE programming language

After porting Vulcan to the IMSAI 8080 and later to CP/M and MS-DOS (as dBASE), Ratliff added commands to accommodate the video screen interface as well as commands for improved control of flow (such as DO WHILE/ENDDO) and conditional logic (such as IF/ENDIF). The IMSAI 8080 microcomputer, manufactured by IMS Associates, Inc. ...

For handling data, dBASE provided detailed procedural commands and functions to open and traverse files (e.g., USE, SKIP, GO TOP, GO BOTTOM, and GO recno), manipulate field values (REPLACE and STORE), and manipulate text strings (e.g., STR() and SUBSTR()), numbers, and dates. Its ability to simultaneously open and manipulate multiple files containing related data lead Ashton-Tate to label dBASE a "relational database," even though it did not meet the criteria defined by Dr. Edgar F. Codd's relational model. A relational database is a database structured in accordance with the relational model. ... Edgar Ted Codd Edgar F. Ted Codd (August 23, 1923 – April 18, 2003) was a British computer scientist who made seminal contributions to the theory of relational databases. ... It has been suggested that Relational database be merged into this article or section. ...

dBASE used a runtime interpreter architecture, which allowed the user to execute commands by typing them in a command line "dot prompt." Upon typing a command or function and pressing the return key, the interpreter would immediately execute or evaluate it. Similarly, program scripts (text files with PRG extensions) ran in the interpreter (with the DO command), where each command and variable was evaluated at runtime. This made dBASE programs quick and easy to write and test because programmers didn't have to first compile and link them before running them. (For other languages, these steps were tedious in the days of single- and double-digit megahertz CPUs.) The interpeter also handled automatically and dynamically all memory management (i.e., no preallocating memory and no hexademical notation), which more than any other feature made it possible for a business person with no programming experience to develop applications.

Conversely, the ease and simplicity of dBASE presented a challenge as its users became more expert and as professional programmers were drawn to it. More complex and more critical applications demanded professional programming features for greater reliability and performance, as well as greater developer productivity.

Over time, Ashton-Tate's competitors introduced so-called clone products and compilers that introduced more robust programming features such as user-defined functions (UDFs) to supplement the built-in function set, scoped variables for writing routines and functions that were less likely to be affected by external processes, arrays for complex data handling, packaging features for delivering applications as executable files without external runtime interpreters, object-oriented syntax, and interfaces for accessing data in remote database management systems. Ashton-Tate also implemented many of these features with varying degrees of success. Ashton-Tate and its competitors also began to incorporate SQL, the ANSI/ISO standard language for creating, modifying, and retrieving data stored in relational database management systems. SQL (commonly expanded to Structured Query Language — see History for the terms derivation) is the most popular computer language used to create, modify and retrieve and manipulate data from relational database management systems. ...

In the late 1980s, developer groups sought to create a dBASE language standard (IEEE 1192). It was then that the language started being referred to as "Xbase" to distinguish it from the Ashton-Tate product. Hundreds of books have been written on dBASE and Xbase programming.

Today, implementations of the dBASE language have expanded to included many features targed for business applications, including the manipulation of the graphical user interface, manipulation of remote and distributed data, Internet functionality, and interaction with modern devices. Despite its functionality and ease of use, the dBASE language's legacy of being "embedded" in a popular commercial product is one of the reasons it is not a dominant standard today.

Programming example

The following example opens an employee table ("empl"), gives every manager who supervises 1 or more employees a 10-percent raise, and then prints the names and salaries.

 USE empl REPLACE ALL salary WITH salary * 1.1 FOR supervises > 0 LIST ALL fname, lname, salary TO PRINT * (comment: reserved words shown in CAPITALS for illustration purposes) 

Note how one does not have to keep mentioning the table name. The assumed ("current") table stays the same until told otherwise. This is in contrast to SQL which almost always needs explicit tables. dBASE used a lot of similar "context" based techniques to reduce the volume of typing needed and facilitate incremental, interactive development. However, one had to be careful about porting (borrowing) programming code that assumed a certain context and it would make writing larger-scale modular code difficult. SQL (commonly expanded to Structured Query Language — see History for the terms derivation) is the most popular computer language used to create, modify and retrieve and manipulate data from relational database management systems. ...

dBASE was also one of the first business-oriented languages to implement string evaluation (long before Perl) Perl, also Practical Extraction and Report Language (a backronym, see below) is a dynamic procedural programming language designed by Larry Wall and first released in 1987. ...

 i = 2 myMacro = "i + 10" i = &myMacro // i now has the value 12 

Here the "&" tells the interpreter to evaluate the string stored in "myMacro" just like it was programming code. This is an example of a feature that made dBASE programming flexible and dynamic, sometimes called "meta ability" in the profession. However, it could also be problematic for pre-compiling and for making programming code secure from hacking. However, dBASE tended to target custom applications for small and medium companies where compile-based security was often less of an issue. For example, nobody would contemplate writing an operating system in the language.

Niches

Although the language has fallen out of favor as a primary business language, some find it an excellent interactive ad-hoc data transformation tool. Unlike SQL, one can easily break data transformations into small steps to analyze and visually inspect. It also allegedly makes it easy to collect existing interactive data manipulation commands into subroutines to become automated scripts, in constrast to competitors which can require starting from scratch to go from interactive mouse commands to program scripts.

It allegedly fills the gap between formal RDBMS and array programming languages such as APL's modern derivatives (J, K, etc.) It is also often used with bulk data file preperation for shipment to external (other vendor) sites via protocols such as FTP and email. Array programming languages (also known as vector or multidimensional languages) generalize operations on scalars to apply transparently to vectors, matrices, and higher dimensional arrays. ... APL (for A Programming Language) is an array programming language based on a notation invented in 1957 by Kenneth E. Iverson while at Harvard University. ... The J programming language, developed in the early 1990s by Ken Iverson and Roger Hui, is a synthesis of APL (also by Iverson) and the FP and FL functional programming languages created by John Backus (of FORTRAN, ALGOL, and BNF fame). ... K is a high level array programming language developed by Arthur Whitney, a very influential member of the APL community. ...

.dbf file format

A major legacy of dBASE is its .dbf file format, which has been adopted in a number of other applications. For example, the shapefile format developed by ESRI for spatial data in a geographic information system uses .dbf files to store feature attribute data. The term XBase is often used for the group of applications. Shapefile is a widely used for spatial data file format format used in geographic information systems. ... ESRI was founded as Environmental Systems Research Institute in 1969 as a privately held consulting firm that specialized in land use analysis projects. ... A geographic information system or geographical information system (GIS) is a system for creating and managing spatial data and associated attributes. ... xBase is the generic term for all programming languages that derive from the original dBase (Ashton-Tate) programming language. ...

dBASE's database system was one of the first to provide a header section for describing the structure of the data in the file. This meant that the program no longer required advance knowledge of the data structure, but rather could ask the data file how it was structured. In information technology, Header refers to supplemental data placed at the beginning of a block of data being stored or transmitted, which contain information for the handling of the data block. ...

External links

• dBASE, Inc.
• An interview with C. Wayne Ratliff describing his career and history of Vulcan/dBASE
• Xbase ( & dBASE ) File Format Description
• C2 Wiki Description of "XBase"