Data base Flashcards
What is a table
when data is organised into files, each file is organised into a number of rows and columns this is referred as a table or ‘flat file ‘
what makes up a table
rows and columns
What is a record
A record is represented as a row in table
What is a field?
A field is a part of a record that stores a single data item represented by a column
What is a key field or primary field
A key field uniquely identifies one record
What is a Query
A query searches and filters data in the database and satisfies the query criteria
What are Forms?
Forms are used to collect data to create a new record, modify an existing record or view records already stored in a table
What are Reports
Reports are used to present results from queries in an effective manner
What are Macros
A small program written to perform a repetitive task automatically
what are the 6 data types and what are they used for
Short Text/string
used for text fields such as names and addresses
Number
used for number fields
Data/Time
used for data fields such as DOB
Currency
used for monetary Valves
AutoNumber
used for ID’s or valves that generate automatically.
Lookup Wizard
used to Select fields from only a selected list.
What is Data Validation
Ensures that the data is reasonable, Sensible and within acceptable limits. It guarantee that data is presented and the correct it will red will display type range or length is entered. in error message an if data is
Data verification
a method of checking data is input correctly e.g. proofing
Types of Data Validation
Data Type Check
Length Check
Range Check
Format Check
Presence Check
Explain Range Check
Ensures that data entered is within a upper and lower limit
Example of Range Check
A Persons month of birth should be in the range
1 Jan to 12 Dec
(lower limit) (Upper Limit)
Explain Presence Check
Ensures that data is presented, it can’t be left blank or null
Explain Data Type Check
This is used to check that all data is entered in the correct data type e.g. numeric, text and data
Explain Format Check
a format check will determined that data entered matches a predetermined pattern.
Explain Length Check
Ensures data is the Correct number of characters e.g. phone number should be 11 digits
What are Database Relationships
Database relationships link two or more tables in a database using a relationship type
What are the different types or relationships
One to One
One to Many
Many to Many
What is a foreign key
The key field is a primary key or key field that has been taken from another table.
It connects the two tables by the foreign key using a relationship.
Benefits of using forms
When data is entered into a form, it is automatically added into the Specified table and stored as part of the database.
The database designer can control the type and format of the data ensuring that it is Kept consistent and accurate.
They can be customised to include colour and the logo.
What are queries (more in-depth)
Queries are a way of searching and extracting data from a database to find the answer to a question.
They queries searched each record and Produces a list of data that satisfies the queries Ceriteria.
