Databases Flashcards
What are the rows in a table called
Fields
What is a primary key
a primary key is a record of unique code something specific to someone or something e.g. registration
what is an entity (table)
an entity is an object in a system that we want to store information about
what are attributes (field)
attributes are the specific characteristic of an entity
what do entities become during implementation
tables
what do attributes become during implementation
fields
what are the data types
text - a mixture of letter and numbers
number - whole or real numbers
date - 26/9/24
time - 10:33
boolean - yes or no / true or false
what are the validation checks
presence check - is the field definitely required
restricted choice - a list of valid choices
field length - maximum number of characters for a text field
range - minimum or maximum value for a numerical field
what is a foreign key
a foreign key is something that can link to tables together
what is a primary key shown as in a table
PK
what is a foreign key shown as in a table
FK
how is a database structured
in tables
what is a record
a collection of data for one object, person or thing
what are fields used for in a database
they provide category headings for each piece of data
what is an example of SQL queries
SELECT fields
FROM table
WHERE criteria
ORDER BY field ASC/DESC;
