Slides in this set
What is SQL?
· this is a query language
· used for accessing and modifying information in a
· provides an interface to relational database systems
SQL is made up of three parts which are DDL, DML &
What is DDL?
· stands for data definition language
· allows users to define the database
· examples are the create table, create index, alter and
drop statements…read more
What is DML?
· stands for data manipulation language
· these command's manipulate data within existing
· examples are the select, update, insert, delete
What is DCL?
· stands for data control language
· is a computer language for controlling access to data
in a database
· examples of DCL commands are grant and revoke…read more
is used to retrieve zero or more rows from one or more
tables in a database. In most applications, SELECT is
the most commonly used Data Manipulation Language
SELECT initial, surname, age, sex FROM client
This is just selecting different fields from the client
table, then putting them into a new table…read more
is used to indicate from which tables the data
is to be taken, as well as how the tables join
to each other.
SELECT initial, surname, age, sex FROM
This is just selecting different fields from the
client table, then putting them into a new