Computer Science - 7 Relational Databases and SQL - 3 Structured Query Language (SQL)

SQL

special-purpose programming language for accessing and manipulating data stored in a relational database

SELECT ...

lists the fields data should be displayed from

FROM ...

specifies the table data should be from

WHERE ...

uses Boolean operators to list a condition records must fall into

BETWEEN ...

data between an inclusive range

LIKE ...

searches for a pattern

Wildcard symbol

*

Wildcard function

selects all fields

ORDER BY ...

organises data in ascending or descending order

ASC

ascending order

DESC

descending order

UPDATE ...

defines what table should be updated

SET ...

defines what value should be changed

DELETE FROM ...

defines what table a record[s] should be deleted from

INSERT INTO ...

inserts new data into a database

VALUES ...

defines the values to be inserted into a table

INSERT INTO + VALUES syntax

INSERT INTO table_name (column1, column2... columnx)

VALUES (value1, value2... valuex)

INNER JOIN ...

returns records in the overlap between two tables

INNER JOIN syntax

INNER JOIN table_name1 IN table_name1.field_name = table_name2.field_name

ASC/DESC syntax

ORDER BY field_name [ASC/DESC]