Update command in SQL

How to use UPDATE Command in SQL

In this post, you will learn how to use UPDATE command in SQL.

UPDATE command is used to update existing record in table. Update command is always used with WHERE clause. If you don't use WHERE Clause, all record will be updated in table so while using UPDATE command, you must be carefull.

Syntax of UPDATE command:

UPDATE Table_Name  SET Column_Name='New_Values' 
WHERE Column_Name='Old_Values' ;


Suppose we have source table: 

Emp_ID	Emp_Name	Emp_Age	Emp_Salay
1	Mohan	25	25000
2	Rakesh	25	25000
3	Ram	25	25000

Now i'm going to update Emp_Name: Mohan to "Mahesh". Now use below code to Update existing record

UPDATE EMP 
SET Emp_Name='Mahesh' WHERE Emp_Name='Mohan';

Now after executing this code, you will get below results:

Emp_ID	Emp_Name	Emp_Age	Emp_Salay
1	Mohesh	25	25000
2	Rakesh	25	25000
3	Ram	25	25000

Update Multiple Values by using below command

UPDATE EMP 
SET Emp_Name='Mahesh' , Emp_Age=30, Emp_Salary=30000 WHERE Emp_ID=1;

Now Output will be :

Emp_ID	Emp_Name	Emp_Age	Emp_Salay
1	Mohesh	30	30000
2	Rakesh	25	25000
3	Ram	25	25000