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Warning:
As of May 12, 2021, CockroachDB v19.2 is no longer supported. For more details, refer to the Release Support Policy.
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.
Tip:
This command can be combined with other ALTER TABLE commands in a single statement. For a list of commands that can be combined, see ALTER TABLE. For a demonstration, see Add and rename columns atomically.
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
This schema change statement is registered as a job. You can view long-running jobs 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 |
+--------+---------+-------------+-----------+---------+
See also
ADD CONSTRAINTSHOW CONSTRAINTSRENAME CONSTRAINTVALIDATE CONSTRAINTDROP COLUMNDROP INDEXALTER TABLESHOW JOBS
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