Karteikarten
Databases
Karten in diesem Stapel (12)
- 1What is a databaseIts a structured persistent store of data
- 2Benefits Of a DatabaseQuicker and more convenient to:
Access Data
Update Data
Search for Data
present data in a usable way - 3What Do databases doProvide Security
Provide Automatic backup
Enforce data integrity rules
Control data redundancy
Provide users with controlled access to data they need - 4What is an entityAny item in the system about which data is stored e.g supermarket, stock, manager
- 5What is an attributeProperty of an entity, equivalent to a field in a database. For example, an attribute of Manager is Name or Age
- 6What is a relationshipExists between entitys. This dictates whether an entity can be connected to multiple entities or just one.
- 7Relational databasesAll data is stored in relationships formed by tables. Data is contained in fields and records are identifiable via their primary key.
- 8Relationship typesThe relationships between entities are of the foundation of databases but it is the type of relation found between entitys where the variation comes from.
- 9One to OneWhere one entity only connects to one other entity. An example is a tutor and an office, each tutor will have one office.
- 10One to ManyMost Common relationship type, where one field is connected to several records in another table. An example is a tutor and qualifications, one tutor can have many qualifications.
- 11Many to manyQuite common. For example a teacher might have numerous students and the students may have numerous teachers,
- 12Composite Primary KeyA primary key that involves more than one attribute.
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- Beschreibung
- AS - Level Computer Science Karteikarten am Databases, erstellt von Nathan King am 05/06/2016.
- Erstellt von
- Nathan King
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