Relational databases

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Key points

  • A relational database is a database that contains multiple tables linked together. Each table should have a Primary Key. The Primary Key uniquely identifies each item (or row or record) in that table. One table is linked to another by referring to a row in one table from another using the Primary Key to identify the row you are referring to. When a field refers to a field which is a Primary Key in another table then it is called a Foreign Key.
  • A relational database allows data to be split into separate tables. This means data can be reused by multiple tables. It prevents duplication of data because only the foreign key is needed to link one record to another.
  • Relational tables also prevent data from being deleted because it is stored in its own table.
  • Updates in a relational database will lead to less errors as one change can be made, rather than many changes to the duplicated data.




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