2.2. First Normal Form (1NF)
Consider a requirement to maintain data about class schedules. We are required to keep the course, section, department name, time, room, room size, professor, student, major, and grade. Suppose that we initially set up a Pascal file with records that look like this:
Classes = RECORD course: ARRAY [1:7] OF CHAR; section: CHAR; time: INTEGER; room: INTEGER; roomsize: INTEGER; professor: ARRAY [1:25] OF CHAR; dept_name: ARRAY [1:10] OF CHAR; students: ARRAY [1:classsize] OF RECORD student ARRAY [1:25] OF CHAR; major ARRAY [1:10] OF CHAR; grade CHAR; END; END;
This table is not in the most basic normal form of relational databases. First Normal Form (1NF) means that the table has no repeating groups. That is, every column ...