DROP COLUMN

Drops the identified column from the table.

column-name
Identifies the column to be dropped. The column name must not be qualified. The name must identify a column of the specified table. The name must not identify a column that was already added or altered in this ALTER TABLE statement. The name must not identify the only column of a table. The name must not identify a partition key of a partitioned table or a distributed table.
CASCADE
Specifies that any views, indexes, triggers, or constraints that are dependent on the column being dropped are also dropped. 55
RESTRICT
Specifies that the column cannot be dropped if any views, indexes, triggers, or constraints are dependent on the column. 55

If all the columns referenced in a constraint are dropped in the same ALTER TABLE statement, RESTRICT does not prevent the drop.


55.
A trigger is dependent on the column if it is referenced in the UPDATE OF column list or anywhere in the triggered action.