The UPDATE
statement is used to modify the existing records in a table.
UPDATE table_name
SET column1 = value1, column2 = value2, ...
WHERE condition;
The following SQL statement updates the first customer (CustomerID = 1) with a new contact person and a new city.
UPDATE Customers
SET ContactName = 'Alfred Schmidt', City= 'Frankfurt'
WHERE CustomerID = 1;
It is the WHERE
clause that determines how many records will be updated.
The following SQL statement will update the ContactName to "Juan" for all records where country is "Mexico":
UPDATE Customers
SET ContactName='Juan'
WHERE Country='Mexico';