Mapa mental
Database Terms
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Database Terms
Key Field
- Piece of data in a database that is unique to a particular record
- Example: Pupil number in a school database
Tables
- Consists of rows and columns
- First row contain field names
- Following rows contain the records
- Columns contain database fields
Relational Databases
- Data is stored in more than one table
- Tables are linked
- Most commercial databases are relational
- Foreign key is a field of one table which is also the key field for another
Problems with flat line systems
- Data redundancy (data is duplicated so more data needs to be entered than is needed)
- When a record is deleted then other data which still may be useful is deleted)
Advantages of Relational Databases
- Time is saved by not having to type as much data
- Entering less data means fewer typing errors
- Data redundancy is redunced
Informações
- Descrição
- GCSE IT Mapa Mental sobre Database Terms, criado por ashleighcattell em 05-06-2014.
- Criado por
- ashleighcattell · jun 2014
- Atualizado
- 19 fev 2016
- Visualizações
- 12
- Avaliação