The Features Of A Relational Database

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P1 - Explain the features of a relational database. This is to be shown as a report or presentation and must discuss the following. • Features: entities; attributes; relationships; • Entities: primary keys, foreign keys; referential integrity; attributes; • Attributes: field properties e.g. data types, size, validation rules • Relationships: one-to-many; one-to-one; many-to-many Relational database – This is a database that contains more than one table of which are linked using key fields. An example could be a library database which could have the ability to have 3 tables. To further this example one table could be Customers so when somebody joins the library a record is generated with their details on such as their name, address…show more content…
You are able to produce restrictions which assures that only acceptable or appropriate data is inputted into the database. Queries – This is what makes the concept of searching for the data you require easily. Queries can be used to obtain a piece of data which can be defined by the user. All of the features above techniques on how a database can receive, store, search and send all types of data to a different database Data Types Databases always keep data as it stores it making the data more efficient and all the different types of data are generally categorised as a specific data type. There is 5 main types of data such as Boolean, date/time, currency Numerical and text. Boolean – This is when data is limited to only 2 different choices. An example is True/False Yes/No Male/Female Date/Time – This kind of data limits you to only being able to use numbers from 1 – 31 for the number of days in the month and 1 – 12 for the number of the month then it examines if the date in fact exists/. There is three different formats for this type of data such as long, medium and short. Long time – 19:25:00 Medium Time – 07:25PM Short time – 19.25 Long date – 30 April 2014 Medium date 30-Apr-14 Short date – 30/04/14 Currency – This type of data is automatically changes the data you enter to possess a £ in front of it and 2 decimal places. An example of this is £5.05 $6.99 Numerical – This is what
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