SQLPrepared ByNiloy SahaDipongker SenDept. Of Computer Science & Engineering

Hamdard University Bangladesh  

Data Definition language(DDL) CREATE,ALTER,DROP

Data Manipulation Language(DML) INSERT,DELETE,UPDATE

Data Query Language(DQL) SELECT

Operations on Table in a Databaseo Set Theory Operations: Union, Intersection, Difference and Cartesian product.o Specific Relational Operations: Selection, Projection, Join, Division

CONTENTS

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

SQL ALTER TABLE SYNTAX

To Add A Column In A Table

ALTER TABLE TABLE_NAMEADD COLUMN_NAME DATATYPE;

Data Definition language(DDL)CREATE,ALTER,DROP

Example:

ALTER TABLE PERSONSADD COLUMN SALARY INT;

SQL ALTER TABLE SYNTAX

To DROP A Column In A Table

ALTER TABLE TABLE_NAMEDROP COLUMN COLUMN_NAME;

Data Definition language(DDL)CREATE,ALTER,DROP

Example:

ALTER TABLE PERSONSDROP COLUMN  COLUMN SALARY;

THE DROP TABLE STATEMENT

       DROP TABLE TABLE_NAME;

Data Definition language(DDL)CREATE,ALTER,DROP

Example:

DROP TABLE PERSONS;

SQL SELECT Syntax

SELECT * FROM TABLE_NAME;

&

SELECT COLUMN1_NAME,COLUMN2_NAMEFROM TABLE_NAME;

Data Query Language(DQL)SELECT

THE SQL INSERT INTO STATEMENT

INSERT INTO TABLE_NAME (COLUMN1,COLUMN2,...)VALUES (VALUE1,VALUE2,...);

Data Manipulation Language(DML)INSERT,DELETE,UPDATE

THE SQL DELETE STATEMENT

DELETE FROM TABLE_NAMEWHERE COLUMN_NAME=VALUE; 

Data Manipulation Language(DML)INSERT,DELETE,UPDATE

THE SQL UPDATE STATEMENT

UPDATE TABLE_NAME

SET COLUMN1=VALUE1,COLUMN2=VALUE2,...

WHERE SOME_COLUMN=SOME_VALUE;

Data Manipulation Language(DML)INSERT,DELETE,UPDATE

Set Theory Operations

Relation: R

First Last Age

Bill Smith 22

Sally Green 28

Mary Keen 23

Tony Jones 32

Relation : S

First Last Age

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

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 Cheesecake

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

Thank You