SQL Server 1

SQL

It is a language which is used to interact with Database. 

Then sub divided into four languages they are

1. DDL
2. DML
3. TCL
4. DCL 

DDL :-

----Data Definition Language,
----Those are used to work on the structure of Tables.

     They can be remembered as DRCAT

D-DROP

R-RENAME

C-CREATE

A-ALTER

T-TRUNCATE

TABLE (OR) RECORD:-Collection of Non-repeated columns .

USING CREATE COMMAND:-

CREATE DB:-

CREATE DATABASE <DATABASE NAME>

Ex:-

CREATE DATABASE HC

To Use:-

USE HC

CREATE TABLE:-

CREATE TABLE J_DEMO (EMPLID CHAR(10) PRIMARY KEY,NAME CHAR(20),DOJ DATE,SALARY INT)

DROP:-

Ex:-

DROP TABLE PS_J_DEMO

RENAME:-

Ex:-

RENAME <OLDTABLENAME> TO <NEWTABLENAME>

RENAME PS_DEMO1 TO PS_DEMO2

ALTER:-

Ex:-

ADD

ALTER TABLE PS_DEMO ADD DOJ DATE

MODIFY 

ALTER TABLE PS_DEMO ALTER COLUMN NAME ENAME

DROP 

ALTER TABLE PS_DEMO DROP COLUMN DOJ 

TRUNCATE:-

Ex:-

TRUNCATE TABLE <TABLENAME>

TRUNCATE TABLE PS_J_DEMO