Ppt INFORMATIVE PRACTICES for class 11th chapter 14

PROJECT WORK :- INFORMATIVE PRACTICES
(TABLE CREATION AND
DATA MANIPULATION
COMMAND )
NAME :- PRASHANT PAWAR
GUIDED BY :- ABHILASH THAKRE

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BEFORE YOU START CREATING TABLES, YOU NEED
A DATABASE ,WHICH IS CONTAINER OF TABLES .
THE DATABASE ACTS AS A CENTRAL POINT OF
ADMINISTRATION FOR THE TABLES IN THE
DATABASE . THE ACTUAL DATA IS STORED IN THE
TABLE , WHICH PROVIDE A STRUCTURED
ORGANIZATION FOR THE DATA AND MAINTAIN
THE INTEGRITY OF THAT DATA
THE FIRST STEP IN SETTING UP A MYSQL
DATABASE IS TO CREATE THE ACTUAL DATABASE
OBJECT ,WHICH SERVERS AS AXONTINER FOR THE
TABLES IN THAT DATEBASE .

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CREATING DATABASES IN AN EASIER TASK
RELATIVELY.IN SIMPLEST FORM THE CREATE
DATABASE COMMAND TAKES THE
FOLLOWING SYNTAX
CREATE DATABASE [IF NOT EXISTS ]
<DATACASE NAME >;
FOLLOWING ARE SOME EXAMPLE DATABASE
CREATION COMMANDS:
CREATE DATABASE myDB ;
CREATE DATABASE IF NOT EXISTS myDB

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CREATING DATABASE IS NOT ENOUGH .
BEFORE YOU CREATE TABLE IN IT ,UOU NEED
TO OPEN THE DATABASE.TO OPEN A
DATACASE,UOU SIMPLY NEED TO WRITE THE
STATEMENT AS PER FOLLOWING SYNTAX
SYNTAX :
USE <databasename>;
For example to open myDB atavase that was
created just before , you to write
USE myDB;

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TO REMOVE A DATABASE , YOU NEED TO
ISSUE A COMMAND WITH FOLLOWING SYNTAX
SYNTAX :
DROP DATABASE <database name>;
THAT IS TO DROP A DATABASE NAMELY
myDB YOU’LL BE WRITING
DROP DATABASE myDB;

TABLES ATE DEGINED WITH THE CREATE TABLE
COMMAND .WHEN A TABLE IS CREATED ITS
COLUMNS ARE NAMED , DATA TYPES AND
SIZES ARE SUPPLIED FOR EACH COLUMNS ARE
NAMED ,DATA TYPES AND SIZES ARE
SUPPLIED FOR EACH COLUMN .EAXH TABLE
MUST HAVE AT LEAST ONE COLUMN .THE
SYNTAX OF CREATE TABLE XOMMAND IS :

CREATE TABLE <table-name>
(<columnname><data type >[(size)],
< columnname><data type>[(<size>)….];
TO CREATE AN EMPLOYEE TABLE WHOSE SCHEMA
IS AS FOLLOWS;
employee (exode,ename,sex,grade,grpss)
THE SQL COMMAND WILL BE
CREATE TABLE EMPLOYEE
(ecode integer ,
Ename char(20),
Sex
char (1),
Grade char ( 2),
Gross decimal ();

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A CONSTRAINT IS A CONDITION OR CHECK
APPLICABLE ON A FIELD OR SET OF FIELDS
THE CONSTRAINTS APPLIED TO MAINTAIN
DATA INTEGRITY ARE ALSO KNOWN AS
INTEGRITY CONSTRAINTS
ONCE AN INTEGRITY CONSTRAINT IS
ENABLED ALL DATA IN THE TABLE MUST
CONFIRM TO THE RULE THAT IT SPECIFIES

CREATE TABLE <table name >
( <column name><data type>[(size
)]<column constraint>,
( <column name><data type>[(size
)]<column constraint>……..
<table constraint>(<column name>,[<column
name>….)])……..)

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THESE XONSTRAINTS ENSURE DATABASE
INTEGRITY ,THUS ARE SOMETIMES CALLED
DATABASE INTEGRITY CONSTRAINTS .A FEW
OF THEM ARE :
UNIQUE CONSTRAINT
PRIMARY KEY CONSTRAINT
DEFAULT CONSTRAINT
CHECK CONSTRAINT
FOREIGN KEY CONSTRAINT

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THIS CONSTRAINT ENSURES THAT NO TWO ROWS
HAVE THE SAME VALUE IN THE SPECIFIED
COLUMN .FOR EXAMPLE ,UNIQUE CONSTRAINT
APPLIED ON ECODE OF EMPLOYEE TABLE ENSURE
THAT NO ROWS HAVE THE SAME ECODE VALUE
AS SHOWN ON NEXT PAGE
NULL IS A SPECIAL KEYWORD IN SQL THAT
DEPICTS AN EMPTY VALUE . A XOLUMN HAVING
NULL IS NOT EMPTY BUT STORES AN EMPTY
VALUE TWO NULL CANNOT BE
ADDED;SUBTRACTEDOR COMPARED

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CREATE TABLE EMPLOYEE
( ecode integer NOT NULL UNIQUE,
Ename char(20) NOT NULL,
Sex char (1) NOT NULL,
Grade char(2),
Gross deccimal );

THIS CONSTRAINT DECLARES A COLUMN AS
THE PRIMARY KEY OF THE TABLE .
CREATE TABLE employee
( ecode integer NOT NULL PRIMAY KEY ,
ename char (2O) NOT NULL ,
sex char (1) NOT NULL ,
Grade char (),
Gross decimal );
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A DEFAULT VALUE CAN BE SPECIFIED FOR A
COLUMN USING THE DEFAULT CLAUSE . WHEN
USER DOES NOT ENTER A VALUE FOR THE
COLUMN THE DEFINED DEFAULT CALUE IS
INSERTED IN THE FIELD . CONSIDER THE
FOLLOWING SQL STATEMENT
sex char (1) DEFAULT ‘E1’ ,
Grade char (),
Gross decimal );
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THIS CONSTRAINT LIMITS VALUE THAT CAN
BE INSERTED INTO A COLUMN OF A
TABLE.FOR INSTANCE CONSIDER THE
FOLLOWING SQL STATEMENT:
sex char (1) NOT NULL ,
Grade char (2) DEFAULT ‘E1’ ,
Gross decimal CHECK (GROSS>2000 );
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WHENEVER TWO TABLES ARE RELATED BY A
COMMON COLUMN , THEN THE RELATED
COLUMN IN THE PARENT TABLE SHOOULD BE
EITHER DECLARED A PRIMARY KEY OR UNIQUE
KEY AND THE RELATED COLUMN IN THE
CHILD TABLE SHOULD HAVE FOREIGN
CONSTRAINT
FOR INSTANCE IF WE HAVE FOLLOWING TWO
TABLES
ITEMS (itemno, description, price, QOH)
Orders(orderno, orderdate , itemno , qty)

CREATE TABLE items
(itemno chat (5) NOT NULL PRIMARY KEY ,
:
);
child table
CREATE TABLE orders
(Orderno number(6,0) NOT NULL PRIMARY KEY,
itemno char (5) REFERENCE Item (itemno),
:
); foreign key
parent table name
primary key of parent table

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IT RESULTS INTO THE REJECTION OF INSERT OR
UPDATE IF A CORRESPONDING VALUE DOES NOT
CURRENTLY EXIST IN THE PRIMARY
IF ON DELETE CASCADE OPTION HAS BEEN SET
THEN UPON DELETING A TUPLE IN THE PARENT
TABLE ALL ITS RELATED RECORDS IN THE CHILD
TABLE GET DELETED . IN THE ABSENCE OF THIS
CLAUSE , IT REHECTS THE DELETION OPERATION
IF CORRESPONDING RECORDS IN THE CHILD
TABLE EXIST
BOTH THE RELATED COLUMNS SHOULD HAVE
THE SAME DATA TYPE

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WHEN A CONSTRAINT IS TO BE APPLIED ON A
GROUP OF COLUMN OF THE TABLE IT IS
CALLED TABLE CONTRAINT
CREATE TABLE items
( icode chara(5)
NOT NULL ,
Descp char (20)
NOT NULL
ROL integer,
QOH integer
CHECK (ROL<QOH)
UNIQUE(icode,descp);

BY DEFAULT MYSQL ASSSIGNS A UNIQUE
NAME TO EACH CONSTRAINT DEFINED BY
YOU .MYSQL NAMES CONSTRAINTS
 SYS_CN
 WHERE N IS AN INTEGER THAT MAKES THE
CONSTRAINT NAME UNIQUE .FOR INSTANCE
SYS_COO3217,SYS_COO1592 ETC. ARE
CONSTRAINT NAMES GENERATED BE MYSQL
HOWEVER YOU YOURSELF CAN NAME A
CONSTRAINT CREATED BY YOU .THIS CAN BE
DONE AS PER FOLLOWING SYNTAX
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CONSTRAINT <name-of-constraint><defintionof-constraint>
creat table Item
( itmno char(5) constraint p_itemkey primay key ,);
Create table orderss
(orderno.
Cconstraint group fkey_orders foreign
key(orderno,itemno)
Reference ordmaster(order#,item)
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)

ONCE YOU HAVE CREATED A TABLE YOU MAY
WANT TO VIEW AN ALREADY CREATED
TABLES STRUCTURE YOU MAY USE DES[RIBE]
COMMAND OF MYSQL*PLUS

DESC[RIBE]<tablename>;
FOR EXAMPLE ,IF UOU WRITE
DESC pet; OR DESCRIBE pet ;
Field

Type

Null

Key

Default

Name

Varchar(20)

Yes

NULL

Owner

Varchar(20)

Yes

NULL

Species

Varchar(20)

Yes

NULL

sex

Char(1)

Yes

NULL

birth

date

Yes

NULL

death

date

Yes

NULL

Extra

YOU CAN DEFINE A TABLE AND PUT DATA
INTO IT WITHOUT GOING THROUGH THE
USUAL DATA DEFINITION PROCESS.THIS CAN
BE DONE B USING SELECT STATEMENT WITH
CREATE TABLE
THE NEW TABLE STORES THE RESULT
PRODUCED BY THE SELECT STATEMENT .THE
NAME OF THE NEW TABLE MUST BE UNIQUE

CREATE TABLE orditem AS
( SELECT icode, descp
FROM items
WHERE QOH <ROL
);
THE NEWLY CREATED TABLE ORDITEM WILL
LOOK AS IT IS SHOWN BELOW:
Icode
106

descp
Cream roll

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AS YOU KNOW THA DATA MANIPULATION
LANGUAGE DIVISION OF SQL IS DEDICATED
TO MANIPULATING DATA IN WNE WAU OR
ANOTHER . THIS SECTION IS GOING TO TALK
ABOUT VARIOUS DML COMMANDS THAT ARE
USED FOR CHANGING DATA IN TABLES OR
THESE COMMAND’S INSERT INTO COMMAND
IS USED FOR ENTERING DATA INTO TABLES

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VALUE ARE PLACED IN AND REMOVED FROM
ATTRIBUTES OR A RELATION WITH THREE
DML COMMANDS INSERT DELETE AND
UPDATE.THESE AND UPDATE THESE ARE ALL
REFERREDTO IN SQL AS UPDATE COMMANDS
IN A GENERIC SENSE .IN OUR TEXT
LOWERCASE “UPDATE “WILL INDICATE THESE
COMMANDS GENERICALLY AND THE
UPPERCASE FOR THE KEYWORD UPDATE

TO INSERT VALUE NULL IN A SPECIFIC
COLUMN UOU CAN TYPE NULL WITHOUT
QUOTES AND NULL WILL BE INSERTED IN
THAT COLUMN . CONSIDER THE FOLLOWING
STATEMEND:

INSERT INTO EMPL(empno ,ename job
,mgr,hiredate , sal ,comm , deptno)
VALUES ( 8100, ‘YASH’ ,’ANALYST’ , NULL ,
‘10-MAY-03’, 6900 ,NULL , 20);

DATES ARE BY DEFAULT ENTERD IN
“YYYY-MM-DD’ FORMAT i.e., FIRST FOUR
DIGITS DEPICTING YEAR FOLLOWED BY TWO
DIGITS MONTH FOLLOED BY A HYPHEN AND A
TWO DIGIT DAY .ALL THIS IS ENCLOSED IN
SINGLE QUOTES.IN THE ABOVE TWO INSERT
INTO STATEMENTS GIVEN IN PREVIOUS
SECTION THE DATES HAVE BEEN GIVEN IN THE
SAME FORMAT

INSERT COMMAND CAN ALSO BE USED TO
TAKE OR DERIVE VALUES FROM ONE
TABLESAND PLACE THEM IN ANOTHER BY
USING IT WITH A QUERY .TO DI THIS SIMPLY
REPLACE THE VALUES CLAUSE WITH AN
APPROPRIATE QUERY AS SHOWN IN THE
FOLLOWING EXAMPLE
INSERT INTO BRANCH1
SELECT*FROM branch2
WHERE GROSS >7000.00;
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IF YOU WANT TO CHANGE ROL TO 400 ONLY
FOR THOSE ITEMS THAT HAVE ROL AS 300
YOU USE THE COMMAND
UPDATE items

SET ROL = 400
WHERE ROL= 300;

THE DELETE COMMAND REMOVES ROWS FROM
A TABLE . THIS REMOVES THE ENTIRE ROWS
,NOT INDIVIDUAL FIELD VALUE .THE DELETE
STATEMENT TAKES THE FOLLOWING GENERAL
FORM :
DELETE FROM<TABLENAME>
[WHERE <predicate>];
TO REMOVE ALL THE CONTENTS OF ITEMS
TABLE UOU USE THE COMMAND
DELETE FROM items;

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CREATE TABLE COMMAND IS USED TO CREATE TABLES IN
DATABASE
INSERT INTO COMMAND IS USED TO INSERT DATA IN THE
TABLE
NULLS ARE INSERTED IN THE TABLE BY TYPING NULL
WITHOUT QUOTES
TO INSERT DATA FROM OTHER TABLE SUBQUERY CAN BE
USED INSIDE INSERT INTO COMMAND
EXISTING DATA IN TABLES CAN BE CHANGED WITHUPDATE
COMMAND
TO UPDATE A TABLE WITH VALUECOMING FROM ANOTHER
TABLE ,UPDATE COMMAND CANUSE SUBQUERIES
ALTER TABLE COMMAND IS USED TO ALTER ,NEW
COLUMNS CAN BE ADDED EXISTING COLUMNS CAN BE
REDEFINED .
DROP TABLE COMMAND DROPS A TABLE FROM A
DATABASE

Ppt INFORMATIVE PRACTICES for class 11th chapter 14

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Ppt INFORMATIVE PRACTICES for class 11th chapter 14