# DROP CONSTRAINT

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

## 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

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

- `DROP COLUMN`
- `DROP INDEX`
- `ALTER TABLE`