reading-notes2

https://m7madmomani2.github.io/reading-notes2

View the Project on GitHub M7madMomani2/reading-notes2

SQL

Image

What is an SQL ?

  • SQL is Structured Query Language, which is a computer language for storing, manipulating and retrieving data stored in a relational database.
  • SQL is the standard language for Relational Database System. All the Relational Database Management Systems (RDMS) like MySQL, MS Access, Oracle, Sybase, Informix, Postgres and SQL Server use SQL as their standard database language.

Why SQL?

  • Allows users to access data in the relational database management systems.
  • Allows users to describe the data.
  • Allows users to define the data in a database and manipulate that data.
  • Allows to embed within other languages using SQL modules, libraries & pre-compilers.
  • Allows users to create and drop databases and tables.
  • Allows users to create view, stored procedure, functions in a database.
  • Allows users to set permissions on tables, procedures and views.

Image

Command & Description

SELECT :

Retrieves certain records from one or more tables.

INSERT

Creates a record.

UPDATE

Modifies records.

DELETE

Deletes records.