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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 (;).

Syntax

	
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.

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