In this post, I am sharing small demonstration to create CQL User Defined Data Type in Cassandra.

Using user defined data types, you can handle multiple fields into one user-defined column.
For example, You can create user-defined data type for Address related columns, in which you can specify a Street name, City name, Pincode, etc.

Create Keyspace if not exists:

CREATE KEYSPACE IF NOT EXISTS dbrnd WITH replication = {'class': 'SimpleStrategy', 'replication_factor' : 3};

Use a Keyspace:

USE dbrnd;

Create user defined data type:

CREATE TYPE dbrnd.EmployeeAddress
(
    StreetName TEXT
    ,CityName TEXT
    ,ZipCode INT
);

Create sample table:
frozen is require to define a column.

CREATE TABLE dbrnd.tbl_EmployeeInfo
(
    EmpID INT PRIMARY KEY
    ,EmpName VARCHAR
    ,EmpAddress frozen<EmployeeAddress>
);

Insert sample records:

INSERT INTO dbrnd.tbl_EmployeeInfo 
(EmpID,EmpName,EmpAddress)
VALUES
(1,'Anvesh',{StreetName:'Kondapuar', CityName:'Hyderabad', ZipCode:580084});

INSERT INTO dbrnd.tbl_EmployeeInfo 
(EmpID,EmpName,EmpAddress)
VALUES
(2,'Neevan',{StreetName:'Hilldrive', CityName:'Bhavnagar', ZipCode:364002});

Select properties of User defined data type column:

cassandra@cqlsh:dbrnd> SELECT EmpAddress.StreetName FROM dbrnd.tbl_EmployeeInfo;

@ Row 1
-----------------------+-----------
 empaddress.streetname | Kondapuar

@ Row 2
-----------------------+-----------
 empaddress.streetname | Hilldrive

(2 rows)