Paradox (database)
| paradox | |
|---|---|
| Basic data
|
|
| developer | Corel |
| Publishing year | 1985 |
| Current version | 11.0.0.676 (April 2016) |
| operating system | Windows |
| category | Database |
| License | Proprietary |
| German speaking | Yes |
| WordPerfect | |
Paradox is a database - development environment or a file-based database format from Borland and Corel , which dBASE , dBASE and dBASE IV is available in the market III 3+ very similar since the 1980s.
construction
Database
Paradox is designed to work with the Borland Database Engine (BDE). This is not part of Paradox itself, but an independent library and is used in many other software products.
The BDE provides access to a relational database as a database interface. In the case of Paradox as the database format, each table (* .DB) and each index occupies one ( primary index * .PX) or two (each secondary index * .XG? And * .YG?) Separate file (s). If a table contains memo fields, validity checks or formatting information, these are also stored in special files (* .MB, * .VAL, * .TV). In the case of multi-user operation, these files are on a network drive, while the PDA instances of the participating computers coordinate shared access with one another through a network control file ("PDOXUSRS.NET") and lock files (* .LCK). Paradox or the DB engine masters so-called "record locking" (locking of individual data records) and is therefore - in contrast to competitors such as Microsoft Access - better suited for multi-user operation.
User interface
The core functionality of Paradox is the forms. These are Windows windows that are designed with the help of the (paid) developer version by placing ready-made input and control elements. This creates screen masks for viewing and entering data.
Programming in the sense of program code lines is not required here. The Paradox runtime environment takes care of loading, locking and saving data sets automatically.
Another user interface are the so-called reports. They are constructed in a similar way to the forms, but are not used for screen display, but for formatted printing.
A form occupies a file, as does a report.
Script language
Program code can be stored for almost all events (such as entries, scrolling or mouse clicks), which changes the Paradox-specific processing of the event in any way. For example, in the case of the "Save" event, inconsistent data can be recognized, a message can be output and the saving can be canceled. In modern terms this can be referred to as scripting language.
In Paradox, the Paradox Application Language (PAL) or ObjectPAL (in the Windows versions) is available as a script language. ObjectPAL is the object-based variant of PAL (Paradox correctly differentiates between object-based and object-oriented). Both are derived from Pascal .
Often the script language is also vaguely referred to as "paradox".
Application programming
Paradox applications are compiled into intermediate code. A Paradox system or a (free) Paradox runtime is still required to run these programs. In contrast to Access, for example, the partial compilation means that the source code does not have to be passed on.
history
Paradox for Windows 1.0 appeared at the beginning of 1993. For marketing reasons, version 1.1 was brought onto the market in 1994 as version 4.5 - as Paradox for DOS was at this version. The Paradox table format is therefore also supported up to level 4 in Paradox for Windows 1.0 and 4.5. Paradox for Windows 5.0 was the actual second generation (Paradox Table Level 5). Then came Paradox 7 in a version for Windows 16-bit and Windows 32-bit ("Table Level 7" - the latest format status). The product Paradox was released to Corel after version 7 for Windows (first version of Corel is Corel Paradox 8). Corel integrated the program into the Professional versions of its WordPerfect Office Suite . It was released in versions 9, 10, 11, 12, X3, X4, X5, X6, X7, X8 and X9 of the Office suite. The Paradox version currently published by Corel is only available in conjunction with Word Perfect Professional X9. The last German version is Paradox 9.
safety
The content of unencrypted Paradox tables can be read with non-paradoxical means, even with simple word processing programs. The Paradox program offers the option of encrypting tables so that a password is required when accessing Paradox. You don't necessarily need a password to decrypt such tables: The encryption rules are fixed and the key for reading is stored in the database, so that no brute-force password search is necessary. Various auxiliary programs such as decryptpdxtable , pxunsec (up to version 4) and pxdazz (up to version 7) can be used to save an unencrypted copy or to determine the password of a paradox table. There are also some universal passwords with which every encrypted paradox table can be opened.
Web links
Individual evidence
- ↑ WordPerfect Office | Free Trial. Retrieved November 16, 2019 .
- ↑ WordPerfect Office | Free Trial. Retrieved November 16, 2019 .
- ↑ Randybeck.com: Paradox Specification. Retrieved July 28, 2011.
- ↑ About.com Delphi Programming: How to open a password protected Paradox DB (if you do not know the password). Retrieved July 28, 2011 (archived February 15, 2016).