title: Cassandra Springboot Frozen column exception
body: <p>I have a springboot application which I hooked up with cassandra. I am trying to create a map inside a map but getting the below exception. </p>
  
  <pre><code>com.datastax.driver.core.exceptions.InvalidQueryException: Non-frozen collections are not allowed inside collections: map&lt;text, map&lt;text, int&gt;&gt;
  </code></pre>
  
  <p>Code</p>
  
  <pre><code>@Table
  @Data
  public class AssessmentSubmissionEntity {
  
      @PrimaryKey()
      private UUID id;
  
      @Column
      private Map&lt;String, Map&lt;String,Integer&gt;&gt; assessmentMap;
  
  
  }
  </code></pre>
  
  <p>man</p>
  
  <pre><code>&lt;dependency&gt;
              &lt;groupId&gt;org.springframework.boot&lt;/groupId&gt;
              &lt;artifactId&gt;spring-boot-starter-data-cassandra&lt;/artifactId&gt;
          &lt;/dependency&gt;
          &lt;dependency&gt;
              &lt;groupId&gt;com.datastax.cassandra&lt;/groupId&gt;
              &lt;artifactId&gt;cassandra-driver-core&lt;/artifactId&gt;
          &lt;/dependency&gt;
          &lt;dependency&gt;
              &lt;groupId&gt;com.datastax.cassandra&lt;/groupId&gt;
              &lt;artifactId&gt;cassandra-driver-mapping&lt;/artifactId&gt;
          &lt;/dependency&gt;
  </code></pre>