SQL – Data Manipulation Language:
Data Manipulation Language commands are used to retrieve, insert, delete and update data in a database.
- SELECT - Select the data from one or more tables from the database.
- INSERT - Insert the data into the tables.
- UPDATE - Update the records in the tables.
- DELETE - Delete records from the tables.
There are two types of Data Manipulation languages:
DML – Declarative:
Declarative programming is a programming paradigm that expresses the logic of a computation without describing its control flow. It attempts to minimize or eliminate side effects by describing what the program should accomplish, rather than describing how to go about accomplishing it.
Each SQL statement is a declarative command.
DML – Procedural:
Procedures, also known as routines, subroutines, methods, or functions simply contain a series of computational steps to be carried out.
Most SQL database implementations extend their SQL capabilities by providing procedural languages. Examples of these are Oracle’s PL/SQL and DB2’s SQL PL.