Update (Delta Lake on Databricks)

Important

This documentation has been retired and might not be updated. The products, services, or technologies mentioned in this content are no longer supported. See UPDATE.

UPDATE [db_name.]table_name [AS alias] SET col1 = value1 [, col2 = value2 ...] [WHERE predicate]

Update the column values for the rows that match a predicate. When no predicate is provided, update the column values for all rows.

Note

(Delta Lake on Databricks) If a column has a NOT NULL constraint, and an INSERT INTO statement sets a column value to NULL, a SparkException is thrown.

WHERE

Filter rows by predicate.

Example 

UPDATE events SET eventType = 'click' WHERE eventType = 'clk'

UPDATE supports subqueries in the WHERE predicate, including IN, NOT IN, EXISTS, NOT EXISTS, and scalar subqueries.

Subquery Examples 

UPDATE all_events
  SET session_time = 0, ignored = true
  WHERE session_time < (SELECT min(session_time) FROM good_events)

UPDATE orders AS t1
  SET order_status = 'returned'
  WHERE EXISTS (SELECT oid FROM returned_orders WHERE t1.oid = oid)

UPDATE events
  SET category = 'undefined'
  WHERE category NOT IN (SELECT category FROM events2 WHERE date > '2001-01-01')

Note

The following types of subqueries are not supported:

  • Nested subqueries, that is, a subquery inside another subquery

  • A NOT IN subquery inside an OR, for example, a = 3 OR b NOT IN (SELECT c from t)

In most cases, you can rewrite NOT IN subqueries using NOT EXISTS. We recommend using NOT EXISTS whenever possible, as UPDATE with NOT IN subqueries can be slow.