From registers to files

Manual record keeping. A class teacher keeps a register of students' attendance and details. With 50 students and 26 working days, that is 1,300 hand-written entries a month, plus totals.

Problems with paper registers:

• Details must be copied again into a new register every year.
• Entries can be written inconsistently (in different ways).
• Registers can be lost or damaged.
• Totals and calculations can be wrong.
• Searching, updating and deleting records is slow.

Computer files solve many of these: records can be copied, searched, added, modified and deleted easily, and the computer does the calculations.

• A file is a container that stores data on a computer. It can hold text, program code, comma separated values (CSV), pictures, audio and video.

The school's two files (the book's running example):

• STUDENT: RollNumber, SName (student's name), SDateofBirth, GName (guardian's name), GPhone and GAddress.
• ATTENDANCE: AttendanceDate, RollNumber, SName and AttendanceStatus (P for present, A for absent), that is, 4 columns.

Example (new): a small clinic writing every patient's visits in a notebook must flip through months of pages to find one patient's history; in a computer file, a search by patient number finds every visit in seconds, and a copy can be kept as a backup.