DML - Data Manipulation Language

It refers to a language that is used to insert, delete and update data in a database. It is used for the manipulation of data in the database.DCL is used together with DML because the changes made by dml wouldn't be saved permanently and have a chance of rolling back. Here are three DML commands:

Insert into command

It is used to insert a data row in a table.

Syntax

INSERT INTO table_name(col1,col2,col3,..) VALUES (value1,value2,value3,...); 
or 
INSERT INTO table_name VALUES (value1,value2,value3,...); 

Example

This example will show the use of the insert command in a table. Insert is used to provide the values or entities into the table through the insert statement

Algorithm

• Step1: Create a table

• Step 2: Insert values into the table using INSERT.

• Step3: Select the table to show output and to see the values that get inserted

CREATE TABLE student(id int,name char(50),roll_no. (50),branch char(50);#table created
INSERT INTO student(id,name,roll_no,branch) VALUES (1,aman,20,cs),
 (2,naman,21,civil), (3,raman,22,bao);#rows are inserted
SELECT * FROM student;#table selected to show output

Output

id	name	 roll_no.	branch
1	aman	 20	        cs
2	naman	 21	        civil
3	raman	 22	        bao

Update Command

It is used to update existing data in a table of a database. It can be used to update single or multiple columns at a time as per the requirement.

Syntax

UPDATE table_name  
SET values_to_update(1_col=1_value,2_col=2_value,....)
WHERE condition;

Here,

• table_name is the name of the table

• 1_col,2_col... are the column

• 1_value,2_value...are the updated value for columns

• conditions are there to select the row on which the value will get updated.

Algorithm

• Step1: Use update to update the data

• Step2: Provide table name

• Step3: Set values to get updated

• Step4: Provide condition of where to perform updation

• Step5: Select the table to show the output

Example

UPDATE student #update operation is to be performed on student table
SET name='monu',roll_no=25#set updated values
WHERE id=1;#condition regarding where to update
SELECT * FROM student;#Select table to show output

Output

id	name	 roll_no.	branch
1	monu	 25	        cs
2	naman	 21	        civil
3	raman	 22	        bao

Delete command

It is used to delete records from a table given. One can delete single or multiple records depending upon the condition provided in the WHERE clause.

Syntax

DELETE FROM table_name WHERE condition;

Here,

• table_name is the name of the table

• table_name is the name of the table

Example

This example will show how the delete command is used to delete or remove the existing data present in the table.

Algorithm

• Step1: Use delete

• Step2: Provide table name

• Step3: Provide condition of where to perform the deletion

• Step4: Select the table to show the output

Input

id	name	 roll_no.	branch
1	monu	 25	        cs
2	naman	 21	        civil
3	raman	 22	        bao

Example

DELETE FROM student#table on which data deletion will occur
WHERE id=1;# condition regarding where to delete
SELECT * FROM student;#Select table to show output

Output

id	name	 roll_no.	branch
2	naman	 21	        civil
3	raman	 22	        bao

Conclusion

This article explains DML which is a part of SQL statements in which commands such as insert, update, and delete take place. Insert is used to insert a data row in a table. The update is used to update data in a database. Delete is used to delete data from the database.