Flashcards
Sem título
Flashcards do conjunto (10)
- 1State the data type for each of the following: (4) a) 23 b) Film Star c) ?@~ d) 14.23a) integer/number
b) text/string
c) text/string
d) Real number - 2Describe validation (1)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. - 3Identify the type of validation used to check: (3) a) A number between 0 and 100 b) Mr, Mrs, Miss, Dr, Rev c) GL19 3ZAa) range check
b) list or lookup
c) Format check/picture check - 4Identify 4 benefits of using a database (4)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.
• 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 unauthorised user can access the database, which may contain personal and sensitive data. - 5Describe 4 methods for keeping data secure (4)methods for keeping data secure:
• Passwords:
o Authorised 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.
• 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)
• Back-ups:
o 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) - 6Explain what is meant by a wildcard and give an example (2):( * ) Any number of characters Like “S*” Finds Smith, Smithers and Scott
- 7Explain the difference between searching and sorting data (2)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.
Searching for data:
One main use a database is to find information quickly. To search for information you use a query. You are “querying the database”. - 8Explain why surname would be an unsuitable key field (1Key filed has to be unique, surnames are not unique as there can be 2 people with the same surname.
- 9Explain what is meant by a report (1):Reports:
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. - 10Explain what is meant by data integrity (1) Describe one way data integrity is improved by the use of a database (2)(1) the correctness of the data stored (2) Ensure that errors are not introduced when data is. using validation checks. ensure that data is updated regularly.
Informações
- Descrição
- FlashCards sobre Sem título, criado por ahmey361 em 13-02-2015.
- Criado por
- ahmey361
- Visualizações
- 0
- Avaliação