2. INTRODUCTION
SQL commands are instructions
used to communicate with the
database to perform specific task
that work with data.
SQL commands can be used not
only for searching the database but
also to perform various other
functions for example, you can
create tables, add data to tables, or
modify data, drop the table, set
3. DATA MANIPULATION LANGUAGE
A DATA MANIPULATION
LANGUAGE (DML) is a set of syntax that
contains SQL commands that are used for
storing, retrieving, modifying, and deleting
data.
These commands are:
SELECT
INSERT
UPDATE
DELETE.
4. SELECT COMMAND
USE
Select command is used to view records from
the table. To view all columns and all rows * can
be specified with select statement.
If user needs to view only certain fields or
columns, then by specifying the names of those
certain fields, columns user can acquire its
output.
SYNTAX
SELECT * from table_name.
SELECT <Column_name> from table_name.
5. TABLE T QUERY RESULT
C1 C2 SELECT * FROM T; C1 C2
1 a 1 a
2 b 2 b
C1 C2 SELECT C1 FROM T; C1
1 a 1
2 b 2
C1 C2 SELECT * FROM T WHERE C1
=1;
C1 C2
1 a
1 a
2 b
EXAMPLE
6. DELETE COMMAND
USE
Delete command is used to delete records in the
table.
In SQL, Delete is used to delete rows in the
table.
It is possible to delete all rows in a table without
deleting the table.
This means that table structure, attributes and
indexes will be intact.
NOTE
Be very careful when deleting records, you
7. SYNTAX
• DELETE * from table_name [WHERE CONDITION]
(if where condition is not used all rows in the table are
removed)
EXAMPLE
• DELETE from customer
WHERE CustomerName=‘Anil Khade’ AND
ContactName=‘Vikrant Kedare’
8. TABLE NAME: person
Sr no. P_id p_name
1 120 Jack
2 121 Rose
3 122 Ram
4 123 Sita
If you want to delete row 1 then,
DELETE * person WHERE p_name=‘Jack’;
1st Row will be deleted.
Sr no. p_id p_name
2 121 Rose
3 122 Ram
4 123 Sita
EXAMPLE
9. UPDATE COMMAND
USE
An SQL UPDATE statement changes the data of
one or more records in a table.
Either all the rows can be updated, or a subset may
be chosen using a condition.
SYNTAX
UPDATE table_name SET column_name = valu
e [, column_name = value ...]
[WHERE condition]
EXAMPLE
UPDATE employee SET location ='Mysore'
WHERE id = 101;
10. Table Name: person
p_id p_name
1 121 Jack
2 122 Rose
3 123 Ram
If you want to update row 1 then,
UPDATE person SET p_name=‘Sita’
WHERE id = 121;
p_id p_name
1 121 Sita
2 122 Rose
3 123 Ram
EXAMPLE
11. INSERT COMMAND
USE
An SQL INSERT statement adds one or more
records to any single table in a relational
database.
SYNTAX
INSERT INTO table_name
VALUES (value1, value2, value3,...valueN);
EXAMPLE
INSERT INTO person
VALUES (124, ‘Laxman’);
12. Table Name:person
p_id p_name
1 121 Jack
2 122 Rose
3 123 Ram
If you want to insert data in 4th row then,
INSERT INTO person
Values(124, ‘Sita’);
p_id p_name
1 121 Jack
2 122 Rose
3 123 Ram
4 124 Sita
EXAMPLE
