Note:
Cockroach Labs supports the current stable release and two releases prior. Therefore, this version will no longer be supported after the Spring 2019 release.

The DROP CONSTRAINT statement is part of ALTER TABLE and removes Check and Foreign Key constraints from columns.

Note:
For information about removing other constraints, see Constraints: Remove Constraints.

Synopsis

ALTER TABLE IF EXISTS table_name DROP CONSTRAINT IF EXISTS name

Required Privileges

The user must have the CREATE privilege on the table.

Parameters

Parameter Description
table_name The name of the table with the constraint you want to drop.
name The name of the constraint you want to drop.

Viewing Schema Changes New in v1.1

Whenever you initiate a schema change, CockroachDB registers it as a job, which you can view with SHOW JOBS.

Example

> SHOW CONSTRAINTS FROM orders;
+--------+---------------------------+-------------+-----------+----------------+
| Table  |           Name            |    Type     | Column(s) |    Details     |
+--------+---------------------------+-------------+-----------+----------------+
| orders | fk_customer_ref_customers | FOREIGN KEY | customer  | customers.[id] |
| orders | primary                   | PRIMARY KEY | id        | NULL           |
+--------+---------------------------+-------------+-----------+----------------+
> ALTER TABLE orders DROP CONSTRAINT fk_customer_ref_customers;
ALTER TABLE
> SHOW CONSTRAINTS FROM orders;
+--------+---------+-------------+-----------+---------+
| Table  |  Name   |    Type     | Column(s) | Details |
+--------+---------+-------------+-----------+---------+
| orders | primary | PRIMARY KEY | id        | NULL    |
+--------+---------+-------------+-----------+---------+
Note:
You cannot drop the primary constraint, which indicates your table's Primary Key.

See Also



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