Control break

{{Short description|A change in the value of one of the keys on which a file}}

{{dablink|Not to be confused with 'Control-Break' displayed in MS-DOS when cancelling an ongoing task by pressing Ctrl+Break key combination.}}

In computer programming a control break is a change in the value of one of the keys on which a file is sorted which requires some extra processing.[https://books.google.com/books?id=EGWeBQAAQBAJ&dq=Control+break+computer+programming&pg=PA201 Computer Programming Languages in Practice: Made Simple Computerbooks], 2014, page 32-227[https://books.google.com/books?id=J88gAQAAIAAJ&q=Control+break+computer+programming Logic and Structured Design for Computer Programmers], 2001, page 74-390[https://books.google.com/books?id=RzAeCgAAQBAJ&dq=Control+break+computer+programming&pg=PT368 Programming Logic and Design, Introductory], 2014[https://books.google.com/books?id=pkwsAQAAIAAJ&q=Control+break+computer+programming Introduction to computer programming RPG], 1972, pages 1-8 For example, with an input file sorted by post code, the number of items found in each postal district might need to be printed on a report, and a heading shown for the next district. Quite often there is a hierarchy of nested control breaks in a program, e.g. streets within districts within areas, with the need for a grand total at the end. Structured programming techniques have been developed to ensure correct processing of control breaks in languages such as COBOL and to ensure that conditions such as empty input files and sequence errors are handled properly.[https://books.google.com/books?id=nauWlPTBcjIC&dq=Control+break+computer+programming&pg=PA512 Academic Press Dictionary of Science and Technology], 1992, pages 307-2112[https://books.google.com/books?id=cE0gAQAAIAAJ&q=Control+break+computer+programming Introduction to computer programming structured COBOL], 1977, pages 8-20

With fourth generation languages such as SQL, the programming language should handle most of the details of control breaks automatically.[https://books.google.com/books?id=Hi9fMnOoRtAC&dq=Control+break+computer+programming+SQL&pg=PA528 Joe Celko's SQL for Smarties: Advanced SQL Programming], 2010, page 528[https://books.google.com/books?id=ytBQAAAAYAAJ&q=Control+break+computer+programming+SQL Oracle SQL], 2003, pages 76-201[https://books.google.com/books?id=HUSeBQAAQBAJ&dq=Control+break+computer+programming+SQL&pg=PA46 Relational Databases: State of the Art Report 14:5] 2014, page 46