4GL – Becoming a blessing for business applications!

Fourth-generation languages (4GL) are the programming languages closer to human languages than a high-level programming language. Most 4GLs are used to access databases. It can be defined as the high-level computer language (like SQL) that allows non-programmer users to write programs to query databases and to generate custom reports.

The objective of designing 4GL was to reduce programming effort, the time it takes to develop software, and the cost of software development.

Some researchers have stated that 4GLs are subset of domain-specific programming languages i.e. DSLs because fourth-generation languages are often been compared to DSL. Still, some people expect that even in advanced development environments like MS Studio, system must have the mixture of all the generations with a very limited use of the first one. This expectation is quite obvious because the need is to have a system which can be extended further without loosing compatibility with older ones. 3GL just offered power only to the programmer but 4GL opened the development environment to a wider population.

A number of different types of 4GLs exist:

• Table-driven (codeless) programming: Here instead of coding, the developer uses Table-driven algorithm programming, an example of this is edeveloper. This kind of tool can be used for business application development. Usually they come in a package allowing for both business data manipulation and reporting

• Report Generators: They take a description of the data format and the report to generate. From that description they either generate the required report directly or they generate a program to generate the report.

• Forms Generators: They manage online interactions with the application system users or generate programs to do so.

• Data Management 4GLs like SAS, SPSS and Stata provide sophisticated coding commands for data manipulation, file reshaping, case selection and data documentation in the preparation of data for statistical analysis and reporting.

Some of the 4GL languages are Agile Business Suite, Clipper, DataFlex, Discovery Machine Modeler, FoxPro, IBM Rational EGL (Enterprise Generation Language) etc.

In terms of applications, a 4GL can be business oriented or it could deal with some technical domain also. The usability improvements obtained by some 4GLs and their environments led to the better exploration for solutions.