Relational databases and structured query language Flashcards
What is a database?
A method in computing of storing a large amount of organised data
What is a table?
In a database, data is organised in to tables of data
What is a field?
Within a table of data, a column is known as a field
What is a record?
Within a table of data, a row is known as a record and contains fields of data that refer to that same data record
What is a primary key?
A unique identifier given to each record (row) in a data table
What is a foreign key?
A field in a table that corresponds to a primary key in a different data table
What is a flat file?
A database which contains a single table of data
What does data redundancy mean?
The duplication of data. This is always to be avoided in a database
What does a relational database contain?
More than one table, and these tables are linked together using relationships
What is SQL?
Structured Query Language which is used to communicate with a
database. SQL is used to manipulate databases and retrieve records
What is SELECT query used for?
Retrieving records from a data table
What is UPDATE query used for?
Manipulating records that already exist in a data table and changing the values
What is INSERT query used for?
Adding additional records in to a data table
What is the DELETE query used for?
Removing records from a data table
