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Warning:
As of April 30, 2020, CockroachDB v2.1 is no longer supported. For more details, refer to the Release Support Policy.
The ALTER TABLE
statement applies a schema change to a table.
Note:
This statement performs a schema change. For more information about how online schema changes work in CockroachDB, see Online Schema Changes.
Subcommands
For information on using ALTER TABLE
, see the documents for its relevant subcommands.
Subcommand | Description |
---|---|
ADD COLUMN |
Add columns to tables. |
ADD CONSTRAINT |
Add constraints to columns. |
ALTER COLUMN |
Change or drop a column's DEFAULT constraint or drop the NOT NULL constraint. |
ALTER TYPE |
New in v2.1: Change a column's data type. |
CONFIGURE ZONE |
New in v2.1: Configure replication zones for a table. |
DROP COLUMN |
Remove columns from tables. |
DROP CONSTRAINT |
Remove constraints from columns. |
EXPERIMENTAL_AUDIT |
Enable per-table audit logs. |
PARTITION BY |
Repartition or unpartition a table with partitions (Enterprise-only). |
RENAME COLUMN |
Change the names of columns. |
RENAME TABLE |
Change the names of tables. |
SPLIT AT |
Force a key-value layer range split at the specified row in the table. |
VALIDATE CONSTRAINT |
Check whether values in a column match a constraint on the column. |
Viewing schema changes
Whenever you initiate a schema change, CockroachDB registers it as a job, which you can view with SHOW JOBS
.