UPDATE

Synopsis

UPDATE table_name SET [ ( column = expression [, ... ] ) ] [ WHERE condition ]

Description

Update selected columns values in existing rows in a table.

The columns named in the column = expression assignments will be updated for all rows that match the WHERE condition. The values of all column update expressions for a matching row are evaluated before any column value is changed. When the type of the expression and the type of the column differ, the usual implicit CASTs, such as widening numeric fields, are applied to the UPDATE expression values.

Examples

Update the status of all purchases that haven’t been assigned a ship date:

UPDATE
  purchases
SET
  status = 'OVERDUE'
WHERE
  ship_date IS NULL;

Update the account manager and account assign date for all customers:

UPDATE
  customers
SET
  account_manager = 'John Henry',
  assign_date = now();

Update the manager to be the name of the employee who matches the manager ID:

UPDATE
  new_hires
SET
  manager = (
    SELECT
      e.name
    FROM
      employees e
    WHERE
      e.employee_id = new_hires.manager_id
  );