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This version of CockroachDB is no longer supported. Cockroach Labs supports the current stable release and two releases prior. Please use one of these supported versions.

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.

  • You can only define the Not Null constraint when creating a table; you cannot add it to an existing table. However, you can migrate data from your current table to a new table with the constraint you want to use.

    Note:
    In the future we plan to support adding the Not Null constraint to existing tables.

  • For more information about NULL, see Null Handling.

Syntax

You can only apply the Not Null constraint to individual columns.

CREATE TABLE table_name ( column_name column_type NOT NULL column_constraints , column_def table_constraints ) )
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



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