Updating data in a database

Use the UPDATE statement in SQL to update the values of a table row. Update lets you update the fields of a specific row or all rows in the table. The UPDATE statement has the following syntax:

UPDATE table_name 
SET column_name1=value1, ... , column_nameN=valueN 
[ WHERE search_condition ] 

Note: There are additional options to UPDATE depending on your database. For a complete syntax description for UPDATE, see the product documentation.

You should not attempt to update a record's primary key field. Your database typically enforces this restriction.

The UPDATE statement uses the optional WHERE clause, much like the SELECT statement, to determine which table rows to modify. The following UPDATE statement updates the e-mail address of John Smith:

UPDATE employees SET Email='[email protected]' WHERE EmpID = 51

Be careful using UPDATE. If you omit the WHERE clause to execute the following statement:

UPDATE employees SET Email = '[email protected]' 

you update the Email field for all rows in the table.

View comments in LiveDocs