What is the use of update command in SQL?

Update command is a data manipulation command which is used to edit the records of a table. It may be used to update a single row based on a condition, all rows or set of rows based on the condition given by the user.

It is used along with the SET clause, operationally, a WHERE clause may be used to match conditions −

Example 1

An example is given below for the use of update command −

update table student set name=’sneha’ where branch=’CSE’;

Example 2

Given below is another example of the usage of update command −

create table employee(ename varchar(30),department varchar(20)); insert into employee values('pinky','CSE'); insert into employee values('priya','ECE'); insert into employee values('hari','EEE'); select * from employee; update employee set ename='sneha' where department='CSE'; select * from employee;

Output

You will get the following output −

pinky|CSE priya|ECE hari|EEE sneha|CSE priya|ECE hari|EEE

Update the value of a column

Given below is an example to update table employee set age=age+1:

create table employee(ename varchar(30),department varchar(20), age number(30)); insert into employee values('ram','projectmanager',40); insert into employee values('priya','assistant director',45); insert into employee values('hari','developer',46); select * from employee; update employee set age=age+2; select * from employee;

Output

You will get the following output −

ram|projectmanager|40 priya|assistant director|45 hari|developer|46 ram|projectmanager|42 priya|assistant director|47 hari|developer|48

Update multiple columns in one statement

Given below is an example to update table salary set −

Here,

• bonus=bonus+5000
• basic=basic+(0.2*bonus)

Example

create table employee(ename varchar(30),department varchar(20), age number(30), salary number(20)); insert into employee values('ram','projectmanager',40,50000); insert into employee values('priya','assistant director',45,45000); insert into employee values('hari','developer',46,30000); select * from employee; update employee set age=age+2,    salary= salary+5000; select * from employee;

Output

You will get the following output −

ram |projectmanager |40|50000 priya|assistant director|45|45000 hari |developer |46|30000 ram |projectmanager |42|55000 priya|assistant director|47|50000 hari |developer |48|35000