• SQL keywords are not case-sensitive which means SELECT is the same as select.
• Database and Table names may be case-sensitive, that depends on the operating system. This means database and table names are case-sensitive on Linux/Unix operating systems and case-insensitive on Windows operating systems.

Comments in SQL

Comments are ingored by database engine. We write comments to provide information and better understanding of the SQL statement.

There are two ways to write comments in SQL statements

1. Begin the comment with — (two hyphens): It is best for single line comment
2. Begin the comment with a slash and an asterisk (/*) and end the comment with an asterisk and a slash (*/): It is Best for multi-line comment.

For single-line comment

-- This is for single line comment

SELECT column_name
FROM tble_name
WHERE condition;

For multi-line comment

/* This is for
multi-line comments*/

SELECT column_name
FROM tble_name
WHERE condition;

SQL Syntax

Syntax for SQL SELECT Statement

Syntax for SQL UPDATE

Syntax for SQL DELETE

Syntax for SQL CREATE DATABASE

Syntax for SQL ALTER DATABASE

Syntax for SQL CREATE TABLE

Syntax for SQL ALTER TABLE

Syntax for SQL DROP TABLE

Syntax for SQL CREATE INDEX

Syntax for SQL DROP INDEX

Syntax for SQL INSERT INTO