CREATE TYPE

Synopsis

To CREATE TYPE statement creates a new user-defined data type in a keyspace. It defines the name of the user-defined type and the names and data types for its fields.

Syntax

Diagram

Grammar

create_type ::= CREATE TYPE [ IF NOT EXISTS ] type_name
                    (field_name field_type [ ',' field_name field_type ...]);

Where

• type_name and field_name are identifiers (type_name may be qualified with a keyspace name).
• field_type is a data type.

Semantics

• An error is raised if the specified type_name already exists in the associated keyspace unless the IF NOT EXISTS option is used.
• Each field_name must each be unique (a type cannot have two fields of the same name).
• Each field_type must be either a non-parametric type or a frozen type.

Examples

Collection types must be frozen to be used inside a user-defined type.

cqlsh:example> CREATE TYPE person(first_name TEXT, last_name TEXT, emails FROZEN<LIST<TEXT>>);

cqlsh:example> DESCRIBE TYPE person;

CREATE TYPE example.person (
    first_name text,
    last_name text,
    emails frozen<list<text>>
);

cqlsh:example> CREATE TABLE employees(employee_id INT PRIMARY KEY, employee person);

cqlsh:example> INSERT INTO employees(employee_id, employee)
                   VALUES (1, {first_name : 'John', last_name : 'Doe', emails : ['[email protected]']});

cqlsh:example> SELECT * FROM employees;

 employee_id | employee
-------------+---------------------------------------------------------------------------
           1 | {first_name: 'John', last_name: 'Doe', emails: ['[email protected]']}

See also

• CREATE TABLE
• DROP TYPE