SQL UPDATE statement is used to modify the existing records in a table. Which record is to be update it is decided by a condition. To specify condition, we use WHERE clause. If you used WHERE clause with UPDATE query to update selected records otherwise , all the records would be affected.
The basic syntax of UPDATE query with WHERE clause is as follows:
SET column1 = value1, column2 = value2...., columnN= valueN
The PRODUCT table having the following records:
Following example, which would update ProductName for a Product which ID is 1.
UPDATE PRODUCT SET ProductName='Acer Laptop' where ProductId=1
Now, Product table would have the following records:
Note: You can also update multiple columns at a time to the selected records.