NOT NULL constraint - CockroachDB

The NOT NULL constraint specifies a column may not contain NULL values.

Details

INSERT or UPDATE statements containing NULL values are rejected. This includes INSERT statements that do not include values for any columns that do not have a DEFAULT value constraint.

For example, if the table foo has columns a and b (and b does not have a DEFAULT VALUE), when you run the following command:

  > INSERT INTO foo (a) VALUES (1);

CockroachDB tries to write a NULL value into column b. If that column has the NOT NULL constraint, the INSERT statement is rejected.

To add the NOT NULL constraint to an existing table column, use the ALTER COLUMN statement.
For more information about NULL, see NULL handling.

Syntax

You can only apply the NOT NULL constraint to individual columns.

not_null_column_level syntax diagram

Parameter	Description
`table\_name`	The name of the table you’re creating.
`column\_name`	The name of the constrained column.
`column\_type`	The constrained column’s data type.
`column\_constraints`	Any other column-level constraints you want to apply to this column.
`column\_def`	Definitions for any other columns in the table.
`table\_constraints`	Any table-level constraints you want to apply.

Usage example

> CREATE TABLE IF NOT EXISTS customers (
    customer_id INT         PRIMARY KEY,
    cust_name   STRING(30)  NULL,
    cust_email  STRING(100) NOT NULL
  );

> INSERT INTO customers (customer_id, cust_name, cust_email) VALUES (1, 'Smith', NULL);

pq: null value in column "cust_email" violates not-null constraint

> INSERT INTO customers (customer_id, cust_name) VALUES (1, 'Smith');

pq: null value in column "cust_email" violates not-null constraint

See also