Constraints

The values of a constrained column must comply with the constraint.

The primary key constraint combines a unique constraint and a not-null constraint. It also defines the default routing value used for sharding.

Example:

Currently primary keys cannot be auto generated and have to be specified if data is inserted, otherwise an error is returned.

Or using a alternate syntax:

Note

Not all column types can be used as PRIMARY KEY.

For further details see .

Example:

Note

For further details see NOT NULL.

A check constraint allows you to specify that the values in a certain column must satisfy a . This can be used to ensure data integrity. For example, if you have a table to store metrics from sensors and you want to ensure that negative values are rejected:

For further details see CHECK.