In Oracle 12c SQL, the DELETE statement is used to remove rows from a table based on a condition. Given the constraints and the information provided, let's evaluate the options:
A . DELETE FROM orders WHERE order_total<1000;: This statement is correctly formatted and will delete rows from the ORDERS table where ORDER_TOTAL is less than 1000. If there is a DELETE CASCADE constraint, corresponding rows in the ORDER_ITEMS table will also be deleted.
B . DELETE * FROM orders WHERE order_total<1000;: This syntax is incorrect. The asterisk (*) is not used in the DELETE statement.
C . DELETE orders WHERE order_total<1000;: This statement is also correctly formatted and is a shorthand version of the DELETE statement without the FROM clause.
D . DELETE FROM orders;: This statement will delete all rows from the ORDERS table, and with DELETE CASCADE, it will also delete all related rows in the ORDER_ITEMS table.
E . DELETE order_id FROM orders WHERE order_total<1000;: This syntax is incorrect because you cannot specify a column after the DELETE keyword.
Reference:
Oracle Database SQL Language Reference 12c Release 1 (12.1), DELETE Statement