SLR 14 Databases (includes SQL)

Database

A collect of data in a formal structure, e.g. tables, but without any formally defined relationship between those tables.

Relational database

Allows the user to specify information about multiple tables and the relationship between those tables

Table

A collection of records within a data are stored in a table.

Record

A collection of fields from a database table relating to a single entity. E.g. a record in a STUDENTS table might include the ID, Name, Age, DoB and Form group for an single student.

Field

A single type of data from a database table. E.g. The fields in a STUDENTS table might be ID, Name, Age, DoB and Form group.

Primary key

A field that uniquely identifies a record in a table

Foreign key

The linking field in the foreign table formed when a relationship is made. The FK becomes by default the PK of the new table.

SQL

The language and syntax used to write and run database queries

SQL: SELECT

A key word in the SQL programming language used for the querying (retrieval) of data. e.g. SELECT Name, Age, Class FROM Students_table WHERE Gender = 'Male'

SQL: FROM

A key word in the SQL programming language used to signify which table(s) we are using. e.g. SELECT Name, Age, Class FROM Students_table WHERE Gender = 'Male'

SQL: WHERE

A key word in the SQL programming language used to filter the results of your query. e.g. SELECT Name, Age, Class FROM Students_table WHERE Gender = 'Male'

SQL: ORDER BY

A key word in the SQL programming language used to order the output from a SELECT query. e.g. SELECT Name, Age, Class FROM Students_table WHERE Gender = 'Male' ORDER BY Class

SQL: INSERT

A key word in the SQL programming language used to INSERT a never record into a database table. e.g. INSERT INTO Students_table VALUES (021, 'Amanda Jones', 15/10/1980, 'F', 'VRO', 'H739')

SQL: UPDATE

A key word in the SQL programming language used to UPDATE an entry in a database table. e.g. UPDATE Students_table SET Form_group = 9S WHERE Form_group = 8S

SQL: DELETE

A key word in the SQL programming language used DELETE records from a database table. e.g. DELETE FROM Students_table WHERE Tutor group = 'FMC'