SQL Syntax

Most of the actions perform on a database are done with SQL statements.

It consists of keywords that are easy to understand.

Example:

Select all records from the Employee table:

SELECT * FROM `employee`;

Database Tables

A database contains one or more tables. Each table is identified by a name (e.g. "Employees" or "Orders"), and
contain records (rows) with data.

Below is a selection from the Employee table used in the examples:

employee table
The table contains six records (one for each employee) and six columns (Employee_id, Employee_name, Address, City, Pincode, and Country).

SQL Commands

SELECT - extracts data from a database
UPDATE - updates data in a database
DELETE - deletes data from a database
INSERT INTO - inserts new data into a database
CREATE DATABASE - creates a new database
ALTER DATABASE - modifies a database
CREATE TABLE - creates a new table
ALTER TABLE - modifies a table
DROP TABLE - deletes a table
CREATE INDEX - creates an index (search key)
DROP INDEX - deletes an index

Semicolon after SQL Statements?

Some database systems require a semicolon at the end of each statement.

Semicolon is use to separate statement in database systems which allow more than
one SQL statement to be executed in the same call to the server.