SQL Syntax

SQL Syntax

SQL follows some unique set of rules and guidelines called Syntax. Some basic guidelines related to SQL Syntax are given below;

• SQL is not case sensitive. Commonly SQL keywords are written in uppercase.
• You can write SQL statements in one line or in multiple lines.
• SQL are depends on relational algebra and tuple are relational calculus.

SQL statement

SQL statements are started with any of the SQL commands/keywords like SELECT, INSERT, UPDATE, DELETE, ALTER, DROP etc. and the statement ends with a semicolon (;).

	
SELECT * FROM table_name;

Why use semicolon after SQL statements ?

Semicolon is used to separate SQL statements. It is a standard way to separate SQL statements in a database system in which more than one SQL statements are used in the same call.

Some Basic Commands

• SELECT: It is used for Retrive data from a database.
• UPDATE: It is used for updates data in database.
• DELETE: It is used for deletes data from database.
• CREATE TABLE: It is used for creates a new table.
• ALTER TABLE: It is used to modify the table.
• DROP TABLE: It is used for deletes a table.
• CREATE DATABASE: It is used for creates a new database.
• ALTER DATABASE:It is used to modify a database.
• INSERT INTO: It is used for inserts new data into a database.
• CREATE INDEX: It is used to create an index (search key).
• DROP INDEX: It is used for deletes an index.