SQL Update
Modify existing records.
SQL UPDATE Statement
The UPDATE statement is used to modify the existing records in a table.
Syntax
UPDATE table_name
SET column1 = value1, column2 = value2, ...
WHERE condition;Be careful when updating records! If you omit the WHERE clause, ALL records in the table will be updated!
UPDATE Example
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;UPDATE Multiple Records
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';