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N H English 55 cards

Cards in this deck (55)

  1. 1What is a database?Organized collection of related data. It is possible to add, edit manage and retrieve data from the database. The structure of the database allows the data to be found and used quickly.
  2. 2What is a field?• A field is a single item of data within a record.
    Example of a field:
    • surname: text
    • date of birth: date/time
    • selling pricing: currency
  3. 3What is a record?• A record consists of a collection of related fields.
    Example of a record:
    • Pupil’s record in a school database only has the fields related to that pupil (surname, forename, date of birth, from, etc.) and not another pupils data.
  4. 4What is a file?• A file (known as a table in Microsoft Access) is a collection of related fields.
    Example of a file / table:
    • The table of records of all pupils in the school.
  5. 5What is a key field?A Key fields uniquely identities each record. No two records have the same data in their key field. Also known as Primary Key.
  6. 6What is the purpose of a key field?The purpose of the key field is to be able to refer to an individual record using a single field. This often takes the form of an identity number, membership number or bar code. E.g. pupil ID.
  7. 7What 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.
  8. 8What are validation rules and validation checks?Validation rules are needed for some fields. As data is entered it is checked to see that it obeys the rules; any data that does not obey the rules is not accepted. You can also set validation text – the text that appears if the data is not acceptable.
  9. 9What is a report?A report is a printed document that contains data from the database, organised and analysed in a certain way. A report from a student database might list the students in each class in alphabetical order.
  10. 10What are forms?Forms are used to make data entry more attractive and secure rather than entering data into raw tables.
  11. 11Why are forms safer and more secure?It is more secure for looking through and displaying the data because the person entering the data need not see all other data or even the other fields. It also allows instructions to be entered.
  12. 12What is a calculated field?Not all data needed in a report may be present in a database. For example a person’s age is never included because it changes day by day. If you want to use age in a report it must be calculated - the calculated field.
  13. 13What are the uses of a database?• Add, change or delete records
    • Search for a particular record
    • Sort the records into a given order
    • Print reports about some aspect of the database
  14. 14Why are records updated?Records do not stay the same forever. They will need to be updated at some point. For example, people get married and change their surname, people move and change their address or prices of goods change.
  15. 15How can you update a record?• Add a new record when a new pupil arrives to a new school
    • Edit existing records when someone move house
    • Delete an old record when an employee leaves a job
  16. 16What do you use to find information quickly?One main use a database is to find information quickly. To search for information you use a query. You are “querying the database”.
  17. 17What is a query?A query specifies what records you are searching for and what fields from the records you would like to display.
    Simple query search (keyword search) – looks for data in one field.
    Complex query search – looks at data with multiple criteria.
  18. 18What is a wildcard?You use wildcard searches in a query for data that you only know part of. For example find all the surnames beginning with ‘S’ you might write:
    surname LIKE “*S”
  19. 19What is sorting data?Results of queries can be presented in a sorted order e.g. alphabetical or in numerical order. Sorts can also be in ascending (A-Z) or descending (Z-A) order.
  20. 20Why do you sort data?• Easier if lists a printed as reports.
    • You can identify best customer by amount they have spent – sort them according to total amount spent.
  21. 21What are the security issues with databases?If data is secure then:
    • It cannot be destroyed
    • It cannot be accidentally or maliciously altered
    • It cannot fall in to the hands of unauthorized people
  22. 22What are the consequences of a business that does not have data that is secure?Consequences for a business where data is not secure include:
    • Loss of customers – unhappy customers go elsewhere • Payments for gods not being received • Bad publicity – all businesses rely on a good reputation • Management unable to make decisions due to lack of information
  23. 23What are the physical methods of keeping data secure?Physical security:
    o Locks on doors
    o Alarms
    o ID cards
    o Biometric systems
  24. 24What do the software methods of keeping data secure consist of?Passwords, access rights, back-ups.
  25. 25What is the password software methods for keeping data secure?o Authorized users are given a username. Each user also has a password that proves the user is really the one whose username is given.
    o Using passwords is a method of authentication.
  26. 26What is the access rights methods for keeping data secure?Access rights (file attributes) can be places on individual files to give:
    o No right to access the file
    o Read access (user can view file but not alter it)
    o Write access (allowing the user to alter the contents of the file)
  27. 27What is the back-up method of keeping data secure?Back-ups: A back-up is a second copy of the data. If a problem arises with the data file, then the back-up copy is used. Back-ups are:
    Saved on to removable media (CD, DVD, memory sticks)
    Stored at a separate location in a locked room or fireproof safe.
    Made regularly (every day)
  28. 28What are some of the benefits of using a database?• Fast access: using a database to find data is much faster compared to paper in a filing cabinet.
    • Easy to edit: a database allows for data to be easily updated and changed.
    • Validation: you can set checks on the data being entered to ensure no inappropriate data gets into the system.
  29. 29What are some of the benefits of using a database?• Reports: results of searches can be used to print reports that may help management in their decision making.
    • Sharing: database can be shared with any number of users on a network. Any user can edit the data.
    • Security: passwords may be set so that no unauthorized user can access the database, which may contain personal and sensitive data.
  30. 30What do the wildcards consist of?*, ?, [ ], [ - ], !
  31. 31What does * wildcard mean and give examplesAny number of characters, like “S*”- finds Smith, Smithers and Scott.
  32. 32What does ? wildcard mean and give examplesAny character like “Ca?” - finds Cat and Cab but not Cart.
  33. 33What does [ ] wildcard mean and give examplesAny character in the brackets , like “10[TS]”- finds 10T or 10S
  34. 34What does [ ] wildcard mean and give examples.Any character within a range of characters- like “10[B-M]” , finds 10D and 10G but not 10T.
  35. 35What does ! wildcard mean and give examples.Any character not in the brackets, like “10[!TW]”- finds 10A and 10 Z but not 10T or 10W.
  36. 36What are the query searches and what do they mean?=
    <
    >
    <>
    AND
    OR
    LIKE
  37. 37What does AND, LIKE and OR query searches mean and give examplesAND - Data is only listed where both conditions are true e.g.Surname = Smith AND Form = 9T
    OR - Data is only listed where either or both conditions are true e.g. Surname = Smith OR Form = 9T
    LIKE - Where a perfect match is not needed e.g. Like Surname = “Jon”
    This will list all surnames that start with “Jon”
  38. 38What are all the data types?Number (integer), Number (real), Text or string, Date/Time, Currency, Boolean, Lists, Picture, Sound, Video
  39. 39Number (integer)A whole number (positive or negative) but no fractions. E.g. 43.
  40. 40Number (real)Any number, including whole numbers and fractions. E.g. 435.655
  41. 41Text or StringLetters, numbers or other characters such as punctuation marks. E.g John Smith
  42. 42Date/timeAny time or date; the way the time or date is displayed depends on how it is formatted. E.g. 04/10/12
    12:15:45
  43. 43CurrencyMoney £ (including foreign currency $ or €). E.g. £13.55
  44. 44BooleanTwo opposing states e.g. true or false, male or female, yes or no. E.g. Yes.
  45. 45ListA list of values, sometimes called a “drop-down” list; only data from the list can be selected. E.g
    Red
    Green
    Blue
  46. 46PictureImage data, from a digital camera, mobile phone, the internet, a clip-art library or scanned in image.
  47. 47SoundA beep from a bar code reader or popular song. E.g. a sound or music clip.
  48. 48VideoA video introduction to computer game or a downloaded film/TV programme. E.g. a moving picture.
  49. 49What are the validation methods?Range check, Type check, Format/Picture check, Length check, Presence check, Lookup list.
  50. 50Range checkThe data entered must be in a sensible range. E.g. If a test is out of 100 marks then only marks in the range of 0 to 100 are acceptable.
  51. 51Type checkThis ensures that the data is of the correct type. E.g .If the number of rooms in a house is being recorded then only an integer (whole number) will be accepted.
  52. 52Format/picture checkIf the data entered has a particular pattern e.g. a postcode or car reg then an input mask can be used to force the data to conform to the rule. Input mask for a database would be LLN NLL e.g. ME1 3BY, where L is a letter and N is number.
  53. 53Length checkThe length of the input is checked for the number of characters used. E.g. If a forename is being entered it is reasonable to assume that it will be between 2 and 18 characters long.
  54. 54Presence checkSome data has to be entered. E.g. If you were ordering goods from the internet you would have to give them your address and the item you were ordering. An error would occur if this data was not present and would not allow the processing of the order to continue.
  55. 55Look-up listIf the data entered consists of a limited number of possible entries then the computer can compare the entry with a list of allowed answers. E.g. If the predicted grade for and exam can only be A, B, C, D, E or U, only these inputs are allowed.

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Flashcards on Untitled, created by N H on 06/02/2015.
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