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 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.