This document provides an overview of SQL (Structured Query Language). It discusses the main SQL clauses including DDL (Data Definition Language) such as CREATE, ALTER, DROP; DML (Data Manipulation Language) such as INSERT, DELETE, UPDATE; and DQL (Data Query Language) such as SELECT. Examples are given for each clause showing how to create and modify tables, insert/update/delete rows, and retrieve data with queries. Set operations like UNION, INTERSECTION, and CARTESIAN PRODUCT are also summarized along with examples of applying them to relations.

1. SQL
Prepared By
Niloy Saha
Dipongker Sen
Dept. Of Computer Science &
Engineering
Hamdard University Bangladesh

2. Data Definition language(DDL)
 CREATE,ALTER,DROP
Data Manipulation Language(DML)
 INSERT,DELETE,UPDATE
Data Query Language(DQL)
 SELECT
Operations on Table in a Database
o Set Theory Operations:
 Union, Intersection, Difference and Cartesian product.
o Specific Relational Operations:
 Selection, Projection, Join, Division
CONTENTS

3. CREATE TABLE TABLE_NAME
(
COLUMN_NAME1 DATA_TYPE(SIZE),
COLUMN_NAME2 DATA_TYPE(SIZE),
COLUMN_NAME3 DATA_ TYPE(SIZE),
…
PRIMARY KEY(COLUMN_NAME1 ));
Data Definition language(DDL)
CREATE,ALTER,DROP
Example:
CREATE TABLE BRANCH
(
BRANCH_NAME CHAR(20),
BRANCH_CITY CHAR(20),
ASSETS INT,
PRIMARY KEY(BRANCH_NAME));
 CREATE TABLE CONSTRUCT

4. SQL ALTER TABLE SYNTAX
 To Add A Column In A Table
ALTER TABLE TABLE_NAME
ADD COLUMN_NAME DATATYPE;
Data Definition language(DDL)
CREATE,ALTER,DROP
Example:
ALTER TABLE PERSONS
ADD COLUMN SALARY INT;

5. SQL ALTER TABLE SYNTAX
 To DROP A Column In A Table
ALTER TABLE TABLE_NAME
DROP COLUMN COLUMN_NAME;
Data Definition language(DDL)
CREATE,ALTER,DROP
Example:
ALTER TABLE PERSONS
DROP COLUMN COLUMN SALARY;

6.  THE DROP TABLE STATEMENT
DROP TABLE TABLE_NAME;
Data Definition language(DDL)
CREATE,ALTER,DROP
Example:
DROP TABLE PERSONS;

7.  SQL SELECT Syntax
SELECT * FROM TABLE_NAME;
&
SELECT COLUMN1_NAME,COLUMN2_NAME
FROM TABLE_NAME;
Data Query Language(DQL)
SELECT

8.  THE SQL INSERT INTO STATEMENT
INSERT INTO TABLE_NAME (COLUMN1,COLUMN2,...)
VALUES (VALUE1,VALUE2,...);
Data Manipulation Language(DML)
INSERT,DELETE,UPDATE

9.  THE SQL DELETE STATEMENT
DELETE FROM TABLE_NAME
WHERE COLUMN_NAME=VALUE;
Data Manipulation Language(DML)
INSERT,DELETE,UPDATE

10.  THE SQL UPDATE STATEMENT
UPDATE TABLE_NAME
SET COLUMN1=VALUE1,COLUMN2=VALUE2,...
WHERE SOME_COLUMN=SOME_VALUE;
Data Manipulation Language(DML)
INSERT,DELETE,UPDATE

11. Set Theory Operations
Relation: R
First Last Age
Bill Smith 22
Sally Green 28
Mary Keen 23
Tony Jones 32
Relation : S
First Last
A
ge
Forrest Gump 36
Sally Green 28
DonJuan DeMarco 27
 Consider the following relations R and S
First Last Age
Bill Smith 22
Sally Green 28
Mary Keen 23
Tony Jones 32
Forrest Gump 36
DonJuan DeMarco 27
 UNION: R U S
 INTERSECTION: R ∩ S
First Last Age
Sally Green 28

12.  Difference: R - S
First Last Age
Bill Smith 22
Mary Keen 23
Tony Jones 32
Set Theory Operations
 Cartesian Product: Produce all combinations of
tuples from two relations.
Relation: R
First Last Age
Bill Smith 22
Mary Keen 23
Tony Jones 32
Relation: S
Dinner Dessert
Steak Ice Cream
Lobster
Cheesecak
e
Result: R X S
First Last Age Dinner Dessert
Bill Smith 22 Steak Ice Cream
Bill Smith 22 Lobster Cheesecake
Mary Keen 23 Steak Ice Cream
Mary Keen 23 Lobster Cheesecake
Tony Jones 32 Steak Ice Cream
Tony Jones 32 Lobster Cheesecake

13. Thank You
