DP4 provides the programming tools to help you produce application programs quickly and easily. If you are new to programming, the fourth generation program development tools will help you to start producing useful programs quickly. If you are an experienced programmer, DP4 provides third and fourth generation tools for you to construct complex applications.
DP4 offers several programming environments:
QA Build, or QAB for short, is the DP4 environment for producing application programs quickly. The QA Build program editor consists of a series of menus and questions which determine how each part of your program is to work. Your responses are used to generate a program that is analysed as partially compiled with the QA Build compiler, and then executed, either with the standard QA Build Interpreter (PROGRUN), or a version of the Interpreter that you have extended by adding to it your own C functions called from QAB, or which contains C functions that call QAB programs.
Report Writer is one of a number of specialised tools for creating specific types of prograsm. Report Writer helps you construct report programs, and one or two other related types of program. Reports output information from your database in a table format. Report Writer uses a similar question-and-answer technique to QA Build. On Microsoft Windows platforms you may want to use third part Report utilities instead. A tool related to Report Writer is Importer, which helps you import data from flat files into a DP4 database.
SQL is an industry-standard language that you can use to interrogate and update the database. You can enter SQL commands interactively, or you can define a file of commands that are interpreted as a batch process. On Microsoft Windows platforms you can use SQL commands via ODBC or ADO to access a DP4 database from any program that supports them. The various ways of using SQL with DP4 are described here.
The DP4 Programming Environment provides a library of functions that you incorporate into your program. DP4 programming with C is available on any platform where DP4 is supported, and many other languages are, or can be, supported on most platforms (On Microsoft Windows platforms you can use the native DP4 database APIs from any tool that supports the use of DLLs, including Visual Basic and Borland Delphi). With this type of program you have the highest degree of control over how the database is accessed and what the user interface is like. See the DP4 C Programming Environment for further details.
DP4 gives you the flexibility to combine QA Build and C/C++ in your application program. A function written in C or C++ can be called from a QA Build program, and a QA Build program can be called from a C or C++ program.