NOT NULL constraint

The NOT NULL specifies a column may not contain 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 .

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 statement.
For more information about NULL, see .

Syntax

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

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 .
`column_constraints`	Any other column-level you want to apply to this column.
`column_def`	Definitions for any other columns in the table.
`table_constraints`	Any table-level 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

Statements

Syntax

Data Types

Spatial Data

Constraints

Details

Syntax

Usage example

See also

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