Karteikarten
Relational Database Flash Cards!
Karten in diesem Stapel (21)
- 1EntityA real world object which contains many attributes. Examples of entities are: Customer, Appointments.
- 2AttributesThis makes up the data within an entity. For example a customer entity would have the attributes: Customer ID, First Name, Surname, Date of Birth, Address and Phone no.
- 3One to One RelationshipThis is a link between 2 entities. For example: 1 husband can only have 1 wife.
- 4One to Many RelationshipThis is where 1 entity has a link to many other entities. E.g. A mother can have many children but a child can only have one mother.
- 5Many to Many RelationshipThis is where many entities share links with many other entities. E.g. A video can be hired by many customers and customers can hire many videos.
- 6Length ChecksThis is where the user can only input a certain amount of characters or cannot above/below an amount of characters.
- 7Presence CheckThis checks if a value has been inputted into a cell. This would be used in choosing a gender from a drop down list on a digital form for example.
- 8LookupThis checks the value inputted against a table of values to confirm the value inputted. This would be used likely be used in drop down lists.
- 9Range CheckThis is used to limit the range of data a user can put in. This would be seen when choosing the month of your date of birth and being restricted to the numbers 1 through to 12.
- 10Type CheckThis is used to check if the user is inputting the correct data type in. For example if they were to input numbers into a box that requested their surname.
- 11Input MaskThis is used to make sure the user inputs data into a specific order/format. For example when to ring someone's home phone number who lives in Weston you must start with '01934'
- 12Primary KeyA unique identifier within table.
- 13Foreign KeyA field within a table which is matched to a primary key in another table.
- 14Importance of Foreign and Primary KeysThey reduce data redundancy within a database because instead of repeatedly typing in the same information over and over again you can type it once into a table and use keys to copy that data into other tables.
- 15FieldA single piece of data in a database.
- 16RecordA group of fields in a database.
- 17ReportA way to present summarize and present information from a database.
- 18QueryA request for information using a chosen criteria.
- 19FormAn easier and more user friendly way of using a database.
- 20Flat File DatabaseThis has all the information in a single table. This makes it straight forward to use but cannot perform complex requests or hold too large amounts of data.
- 21Relational DatabaseThis can store information across multiple tables which can all link to each other using keys. This reduces effort of inputting data and the data redundancy within the table whilst also improving the data reliability.
Informationen
- Beschreibung
- This can be used for computing and IT revision
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- lbradford811
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