Using a compound primary key
A compound primary key consists of more than one column and treats the first column declared in a definition as the partition key.
As shown in the music service example, a compound primary key consists of more than one column and treats the first column declared in a definition as the partition key. To create a compound primary key, use the keywords, PRIMARY KEY, followed by the comma-separated list of column names enclosed in parentheses.
CREATE TABLE emp (
empID int,
deptID int,
first_name varchar,
last_name varchar,
PRIMARY KEY (empID, deptID)
);