DROP TABLE v16
Name
DROP TABLE — Remove a table.
Synopsis
DROP TABLE <name> [CASCADE | RESTRICT | CASCADE CONSTRAINTS]
Description
DROP TABLE removes tables from the database. Only the owner can remove a table. To empty a table of rows without removing the table, use DELETE. DROP TABLE removes any of the target table's indexes, rules, triggers, and constraints.
Parameters
name
The name (optionally schema-qualified) of the table to drop.
RESTRICT
Include the RESTRICT keyword to prevent dropping the table if any objects depend on it. This is the default behavior. The DROP TABLE command reports an error if any objects depend on the table.
CASCADE
Include the CASCADE clause to drop any objects that depend on the table.
CASCADE CONSTRAINTS
Include the CASCADE CONSTRAINTS clause to drop any dependent constraints on the specified table, excluding other object types.
Examples
This example drops a table named emp that has no dependencies:
DROP TABLE emp;
The outcome of a DROP TABLE command varies depending on whether the table has any dependencies. You can control the outcome by specifying a drop behavior. For example, suppose you create two tables, orders and items, where the items table depends on the orders table:
CREATE TABLE orders (order_id int PRIMARY KEY, order_date date, …); CREATE TABLE items (order_id REFERENCES orders, quantity int, …);
EDB Postgres Advanced Server performs one of the following actions when dropping the orders table, depending on the drop behavior that you specify:
- If you specify
DROP TABLE orders RESTRICT, EDB Postgres Advanced Server reports an error. - If you specify
DROP TABLE orders CASCADE, EDB Postgres Advanced Server drops theorderstable and theitemstable. - If you specify
DROP TABLE orders CASCADE CONSTRAINTS, EDB Postgres Advanced Server drops theorderstable and removes the foreign key specification from theitemstable. It doesn't drop theitemstable.