The UPDATE Statement

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The UPDATE Statement

In this section, you will learn use of the update statement.

In this section, you will learn use of the update statement.

The UPDATE Statement

     

The UPDATE statement is used to modify the data in the database table through a specified criteria. In the given syntax of update statement the keyword SET is used to assign a new value to a selected columns. The statement also uses WHERE clause. 

It simply work as a select statement, if the given criteria match with the table content then the selected row will be effected if not then the whole table will be effected.

Lets consider a record with a emp_name of "Amar" as shown below.

 

 

 

 

emp_name Position Salary email_id
Amar Designer 8000 [email protected]

If we want to change the salary to the employee with a emp_name of "Amar" then we should use the following SQL statement :

Syntax:

UPDATE 'table_name' SET 'field_name' = 'new_value'
WHERE 'field_name' = 'field_value';

for example: 
 
UPDATE Person SET Salary = 10000
WHERE emp_name = 'Amar';

The output of the above code will be :

emp_name Position Salary email_id
Amar Designer 10000 [email protected]


To Update several Columns in a Row: If we want to change the multiple values of a table like in employee table we want to change Position and email_id then we have to write the following code in which we set the email_id and position by SET keyword and putting condition by keyword WHERE for emp_name is 'Amar'. 

UPDATE employee
SET email_id = '[email protected]', Position = 'Programmer'
WHERE emp_name = 'Amar';

The output of the above code will be:

emp_name Position Salary email_id
Amar Programmer 10000 [email protected]

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