Karteikarten
Topic 8 Database flashcards
Karten in diesem Stapel (23)
- 1What is an example and description of a number (integer)?-43
-A whole number (positive or negative) but no fractions - 2What is an example and description of a number (real)?-435.256
-Any number, including whole numbers ad fractions - 3What is an example and description of a Text or String?-John Smith
-Letters, numbers or other characters such as punctuation marks - 4What is an example and description of a Date/Time?-04/10/12
12:15:45
- Any time or date; the way the time or date is displayed depends on how it is formatted - 5What is an example and description of Currency?-£13.55
-Money £ (including foreign currency $ or €) - 6What is an example and description of Boolean?-Yes
-Two opposing states e.g. true or false, yes or no, male or female - 7What is an example and description of lists?-Red,Green,Blue
-A list of values, sometimes called a "drop down" list; only data from the list can be selected. - 8What is a description of a picture?-Image data, from a digital camera, mobile phone, the internet, a clip art library or a scanned in image.
- 9What is an example and a description of a sound?-A sound or music clip.
-A beep from a barcode reader or a popular song. - 10What is an example and description of a video?-A moving picture
-A video introduction to computer game or a downloaded film/TV program - 11What is a database?-Is an organised collection of related data. It is possible to add, edit, manage and retrieve data from a database. The structure of a database allows data to be found and used quickly.
- 12What is a field?-Is an single item of data within a record
- 13What is a record?-Consists of a collection of related fields
- 14What is a file/ table?-Is a collection of related fields
- 15What is a key field?-Key fields uniquely identifies each record. No two records have the same data in their key field. Also known as a primary key.
- 16What is the purpose of a key field?-Is to be able to refer to an individual record using a single field. This often takes the form if an identity number, membership number or bar code.
- 17What is validation?Data entered in to a database must be sensible or we get GIGO. Validation methods can only ensure reasonable and sensible data is input in to a system, but there is no certainty that the data is correct.
- 18What is an description and example of a range check?-The data entered must be in a sensible range.
-If a test it taken out of 100 marks then the only marks in the range of 0 to 100 are acceptable - 19What is a description and example of a type check?-This ensures that the data is of the correct type
-If the number of rooms in a house is being recorded then only an integer (whole number) will be accepted. - 20What is a description and example of format/picture check?-If the data entered has a particular pattern e.g. a postcode or car registration then an input mask can be used to force the data to conform.
-Input mask for a database would be LLN NLL e.g.ME1 3BY- where L is a letter and N is a number - 21What is a description and example of length check?-The length of the input is checked for the numbers of characters used.
-If a forename is being entered it is reasonable to assume that it will be between 2 and 18 characters long. - 22What is a description and example of presence check?-Some data has been entered.
-If you were ordering goods from the internet you would have to give them your address and item you were ordering. An error would occur if this data was not present and would not look the processing of the transaction to continue. - 23What is a description and example of lookup list?-If the data entered consists of possible entries then the computer can compare the entry with a list of allowed answers.
-If the predicted grade for an exam can only be A,B,C,D,E or U, only these inputs are allowed.
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- Karteikarten am Topic 8 Database flashcards, erstellt von lebrc004 am 11/02/2015.
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