SQL STATEMENTS

The SQL statements can be categorized as:

 DATA DEFINITION LANGUAGE (DDL): is used by to define the database, data types, structures, and constraints on the data. Some of the DDL commands are:

• CREATE: used to create new database object such as table.
• ALTER: used to modify the database object.
• DROP: used to delete the objects.

DATA MANIPULATION LANGUAGE (DML): is used to manipulate the data in the database objects. Some of the DML commands are:

• INSERT: used to insert a new record in the table
• UPDATE: used to modify an existing record in the table
• DELETE: used to delete a record from a table

DATA CONTROL LANGUAGE (DCL): is used to control the data access in the database. Some of the DCL commands ae:

• GRANT:used to assign permissions to the user to access a database object.
• REVOKE:used to deny permissions to users to access the database.

DATA QUERY LANGUAGE (DQL): is used to query data from the database objects. SELECT is the DQL command that is used to select data from the database in different ways and formats.