SQL is a language used to create, access, and manipulate databases. It allows users to define databases by creating tables with columns and rows, and then manipulate the data in those tables using commands like SELECT to query data, INSERT to add new rows, UPDATE to modify existing rows, and DELETE to remove rows. Common SQL commands fall into categories like DDL for data definition, DML for data manipulation, and TCL for transactions.

1. SQL
Structured Query Language

2. SQL is language use for creating, accessing and
manipulating database systems. SQL statements are used
to retrieve and update data in a database. SQL works with
database programs like MS Access, DB2, Informix, MS SQL
Server, Oracle, Sybase, etc.
Database is collection of data Stored in table format.
Each table is identified by a name . Tables contain records
(rows) and columns.
Below is an example of a table called “employee":
Id Name Sal
1 Aditya 25000
2 Vaidehi 17000

3. For Performing Operations on the data stored in
tables different commands are available in sql.
SQL commands are categorized in different groups
DDL : Data Definition Language
DML: Data Manipulation Language
TCL : Transaction Control Language

4. DATA DEFINITION LANGUAGE(DDL)
DDL include three commands
•CREATE - Creates a new database table or object.
• ALTER - Alters (changes) a database table or Object
We can Add ,Modify and Drop column
• DROP - Deletes a database table or Object

5. Create
Syntax:
Create table table_name( column1 datatype(size),
column2 datatype(size),
.
.
columnn datatype(size));
Example:
Create table Employee(id number(3),
name varchar2(10),
salary number(10));

6. EFFECT OF CREATE COMMAND
Id Name salary

7. Alter
Syntax:
Alter table table_name
ADD/MODIFY/DROP (column specification);
Example
Alter table employee Add (Address varchar2(10));
Alter table employee modify(Address varchar2(12));
Alter table employee Drop(Adress );

8. EFFECT OF ALTER COMMAND
ID NAME SALARY
Alter table employee Add (Address varchar2(10));
ID NAME SALARY ADDRESS
Alter table employee Drop(Address );
ID NAME SALARY

9. Drop
Syntax:
Drop table table_name;
Example:
Drop table employee;

10. DATA MANIPULATION LANGUAGE (DML)
Data Manipulation Language (DML) include
select,update,delete,insert:
•SELECT - Use for retrieving data from a database table
•UPDATE – Use for updating data in a database table
•DELETE – Use for deletes data from a database table
•INSERT - Use for inserts new data into a database table

11. SELECT STATMENT
Syntax
Select * or column1,column2..column n from table_name
[where condition];
Example
Select * from employee;
Select name from employee;

12. INSERT STATMENT
Syntax
INSERT INTO table_name[(column1,column2,…)]
VALUES (value1, value2,....) ;
Example;
Insert into emp(id,name,salary)values(101,’Aditya’,100000);
Id Name Sal
1 Aditya 100000
2 Vaidehi 17000

13. UPDATE STATMENT
Syntax
UPDATE table_name
SET column_name = new_value
WHERE column_name = some_value;
Example:
update emp
set salary=50000
where id=101;
Id Name Sal
101 Aditya 50000
102 Vaidehi 17000

14. DELETE STATMENT
Syntax
DELETE FROM table_name
[WHERE column_name = some_value ]
Example:
delete from employee
where id=101;
Id Name Sal
102 Vaidehi 17000

15. Thank you!