2.1.5 Databases

2.1.5 Databases

1. What is a database?

   • A database is a persistent, organised store of data.
     • 'Persistent' means that once data has been put in the database it can be stored and accessed again later.
   • Data handling software, e.g. Microsoft Access, helps us to create and use databases.
   • There are different components within a database.
     • A record is all of the data about a single person/thing.
     • An entity is a category of person/thing that the database holds information about, e.g. users, products, staff. There is a table for each entity.
       • A database that contains only one table is called a flat file database.
   • The software used to access a database is called client software.

2. Relational databases

   • Relational databases are databases containing more than one linked table.
     • They help to reduce data redundancy.
   • The databases need to be linked

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