SQL UPDATE Statement

The SQL UPDATE statement is used to modify data in a database table. It is used to update existing records in a table, rather than inserting new ones like the INSERT statement. The UPDATE statement is an essential part of any SQL query and is commonly used to keep database records up to date.

Syntax

UPDATE table_name
SET column1 = value1, column2 = value2, ...
WHERE condition;
    

Example

UPDATE customers
SET city = 'Los Angeles'
WHERE customer_id = 123;
    

This example updates the city for the customer with ID 123 to "Los Angeles" in the "customers" table.

Options

• UPDATE: The table to update.
• SET: The columns to update and the new values to set them to. Multiple columns can be updated in a single UPDATE statement.
• WHERE: The condition that must be met for a row to be updated. This is optional, but if it is omitted, all rows in the table will be updated. It is usually a good idea to include a WHERE clause to specify which rows to update, to avoid accidentally updating too many rows.
• LIMIT: The maximum number of rows to update. This is optional and can be used to limit the number of rows affected by the UPDATE statement. For example:

  UPDATE customers SET city = 'Los Angeles' LIMIT 10

There are many other options and clauses that can be used with the UPDATE statement, such as JOIN and ORDER BY. You can learn more about these and other advanced topics in our SQL tutorials and references.