A host language interface to a relational database using a SQL/ PASCAL preprocessor

SQL/PASCAL is a relational database query system which is implemented using the preprocessor method. The application program contains Pascal statements and data retrieval statements (a distinguishes the data retrieval statements from the Pascal statements). The data retrieval statements include the host variable declaration statement, the host variable, the database name, the password assignment statements, and the query statements. SQL query statements, embedded in the application program, are analyzed and converted to proper Pascal statements by the SQL/PASCAL precompiler, before the normal host language compilation. At the same time, the precompiler collects the access modules required to load with the resulting pure Pascal program. The loaded module is then executed to get the information from the database. The advantages gained using the preprocessor method are compared with the other host language interface method, the call procedure method. General topics concerning the relational database system and relational languages are also discussed.