dBase

In the late 1960s, Fred Thompson at the Jet Propulsion Laboratory (JPL) was using a Tymshare product named RETRIEVE to manage a database of electronic calculators, which were at that time very expensive products. In 1971, Thompson collaborated with Jack Hatfield, a programmer at JPL, to write an enhanced version of RETRIEVE, which became the JPLDIS project. JPLDIS was written in FORTRAN on the UNIVAC 1108 mainframe, and was presented publicly in 1973. When Hatfield left JPL in 1974, Jeb Long took over his role.[15]

While working at JPL as a contractor, C. Wayne Ratliff entered the office football pool. He had no interest in the game as such, but felt he could win the pool by processing the post-game statistics found in newspapers.[16] In order to do this, he turned his attention to a database system and, by chance, came across the documentation for JPLDIS. He used this as the basis for a port to PTDOS on his kit-built IMSAI 8080 microcomputer, and called the resulting system Vulcan (after the home planet of Mr. Spock on Star Trek).[17][18][19]

George Tate and Hal Lashlee had built two successful start-up companies: Discount Software, which was one of the first to sell PC software programs through the mail to consumers, and Software Distributors, which was one of the first wholesale distributors of PC software in the world. They entered into an agreement with Ratliff to market Vulcan, and formed Ashton-Tate[20] (the name Ashton was chosen purely for marketing reasons) to do so. Ratliff ported Vulcan from PTDOS to CP/M. Hal Pawluk, who handled marketing for the nascent company, decided to change the name to the more business-like "dBase". Pawluk devised the use of lower case "d" and all-caps "BASE" to create a distinctive name. Pawluk suggested calling the new product version two ("II") to suggest it was less buggy than an initial release. dBase II was the result and became a standard CP/M application along with WordStar and SuperCalc.[21]

In 1981, IBM commissioned a port of dBase for the then-in-development PC. The resultant program was one of the initial pieces of software available when the IBM PC went on sale in the fall of 1981. dBase was one of a few "professional" programs on the platform then, and became a huge success. The customer base included not only end-users, but an increasing number of "value added resellers", or VARs, who purchased dBase, wrote applications with it, and sold the completed systems to their customers. The May 1983 release of dBase II RunTime further entrenched dBase in the VAR market by allowing the VARs to deploy their products using the lower-cost RunTime system.

Although some critics stated that dBase was difficult to learn, its success created many opportunities for third parties. By 1984, more than 1,000 companies offered dBase-related application development, libraries of code to add functionality, applications using dBase II Runtime, consulting, training, and how-to books. A company in San Diego (today known as Advisor Media) premiered a magazine devoted to the professional use of dBase, Data Based Advisor; its circulation exceeded 35,000 after eight months.[22] All of these activities fueled the rapid rise of dBase as the leading product of its type.[23][24]

Screenshot of Dbase III Plus

As platforms and operating systems proliferated in the early 1980s, the company found it difficult to port the assembly language-based dBase to target systems. This led to a rewrite of the platform in the C programming language, using automated code conversion tools. The resulting code worked, but was essentially undocumented and inhuman in syntax, a problem that would prove to be serious in the future.

In May 1984, the rewritten dBase III was released. Although reviewers widely panned its lowered performance, the product was otherwise well reviewed. After a few rapid upgrades, the system stabilized and was once again a best-seller throughout the 1980s, and formed the famous "application trio" of PC compatibles (dBase, Lotus 123, and WordPerfect). By the fall of 1984, the company had over 500 employees and was taking in US$40 million a year in sales (equivalent to $113 million in 2022), the vast majority from dBase products.

There was also an unauthorized clone of dBase III called Rebus in the Soviet Union. Its adaptation to the Russian language was reduced to the mechanical replacement of the name, the russification of the help files and the correction of the sorting tables for the Russian language.

Introduced in 1988,[25] after delays,[26] dBase IV had "more than 300 new or improved features". By then, FoxPro had made inroads, and even dBase IV's support for Query by Example and SQL were not enough.

Along the way, Borland, which had bought Ashton-Tate, brought out a revised dBase IV in 1992[27] but with a focus described as "designed for programmers" rather than "for ordinary users".

Full timeline for all the dBase Products.

• dBASE PLUS: A Windows-based database.
• dBASE 2019: Successor of dBASE PLUS 12. Requires Windows Vista or later. Only 32-bit Windows Vista is supported, but 32 and 64-bit Windows Server 2012 are supported.
• dBASE CLASSIC:[35] dBASE V for DOS without DOS emulator, originally found in dBASE PLUS 9. Also includes original documentation included in the installation in PDF format.
• dbDOS: A MS-DOS emulator.

• dbDOS PRO: Successor of dbDOS 1.5.1, starts with version 2.
• dbDOS Open Source: Open source version of dbDOS.
• dbDOSv: Successor of dbDOS PRO 7.

• dbfUtilities: .dbf file processing utilities.

• dbfCompare: Compares differences between tables.
• dbfExport: Converts .dbf table to other file formats.
• dbfImport: Converts other file formats into .dbf format.
• dbfInspect: Read, modify, insert, delete, pack, and print using any dBASE IV and later tables.

• dumpSQL: Extracts all of the records of an existing table into a new table in the supported file formats.
• moveSQL: Transfers all of the records of an existing table into a new table in the supported database formats.

Today, implementations of the dBase language have expanded to include many features targeted for business applications, including object-oriented programming, manipulation of remote and distributed data via SQL, Internet functionality, and interaction with modern devices.

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 supervisors > 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. Because of its origins as an interpreted interactive language, dBase used a variety of contextual techniques to reduce the amount of typing needed. This facilitated incremental, interactive development but also made larger-scale modular programming difficult. A tenet of modular programming is that the correct execution of a program module must not be affected by external factors such as the state of memory variables or tables being manipulated in other program modules. Because dBase was not designed with this in mind, developers had to be careful about porting (borrowing) programming code that assumed a certain context and it would make writing larger-scale modular code difficult. Work-area-specific references were still possible using the arrow notation ("B->customer") so that multiple tables could be manipulated at the same time. In addition, if the developer had the foresight to name their tables appropriately, they could clearly refer to a large number of tables open at the same time by notation such as ("employee->salary") and ("vacation->start_date"). Alternatively, the alias command could be appended to the initial opening of a table statement which made referencing a table field unambiguous and simple. For example. one can open a table and assign an alias to it in this fashion, "use EMP alias Employee", and henceforth, refer to table variables as "Employee->Name".

Another notable feature is the re-use of the same clauses for different commands. For example, the FOR clause limits the scope of a given command. (It is somewhat comparable to SQL's WHERE clause.) Different commands such as LIST, DELETE, REPLACE, BROWSE, etc. could all accept a FOR clause to limit (filter) the scope of their activity. This simplifies the learning of the language.

dBase was also one of the first business-oriented languages to implement string evaluation.

 i = 2
 myMacro = "i + 10"
 i = &myMacro
 * comment: i now has the value 12

Here the "&" tells the interpreter to evaluate the string stored in "myMacro" as if it were programming code. This is an example of a feature that made dBase programming flexible and dynamic, sometimes called "meta ability" in the profession. This could allow programming expressions to be placed inside tables, somewhat reminiscent of formulas in spreadsheet software.

However, it could also be problematic for pre-compiling and for making programming code secure from hacking. But, dBase tended to be used for custom internal applications for small and medium companies where the lack of protection against copying, as compared to compiled software, was often less of an issue.

ASSIST application in dBase III+.