System and method for accessing cobol data with a cobol compatible structured query language

摘要

A system (10) and method enabling use of a COBOL compatible structured query language (CCSQL) to manipulate data stored in a COBOL data file (90), which is in a non-first normal, hierarchical format. Initially, a dictionary generator subsystem (68) creates a corresponding dictionary (74) for each COBOL data file (90). In the dictionary (74), the NF2 hierarchical logical relationship between the items and attributes (hierarchical nature) of each item of a COBOL data file are defined. Thereafter, whenever a new COBOL data file is produced, a corresponding dictionary is generated. When a user enters a request in the CCSQL format to query a COBOL data file, the request is parsed. The definitions in the dictionary are used by the CCSQL kernel (78) to manipulate the data in response to the user's query. A command interpreter (64) processes the request to determine the appropriate data manipulation to apply and initiates a CCSQL kernel request that carries out the intended action, with reference to the corresponding dictionary (74). For example, the request may require that certain items from a COBOL data file be extracted to produce a report (82). Because the hierarchical logical relationships between the items in the COBOL data are defined in the corresponding dictionary, a CCSQL report generator subsystem can produce the report using data extracted from the COBOL data file in accordance with criteria provided by the user, but without converting the data in the COBOL data files to a 1NF. COBOL programs with embedded CCSQL commands are preprocessed to convert the CCSQL commands to a COBOL compatible structured language that uses the dictionaries to access data referenced in the COBOL data files.