Database Normalisation

It's all about reorganising tables to avoid data duplication and improve maintainability. For a scientific methodology, see C.J.Date's book on databases.

Example: a Student/classes database. Unnormalized would be e.g. 1 table with columns: Student ID + student name + class name + class description, with a record for each class a student takes. Normalized would be table 1: Student ID+ student name, table2: class ID + class name + class description, and table 3: student ID + class ID.

This should answer your questions:
Database Normalization Basics 209534

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