title: Insert duplicate rows for subjects
body: <p>Is there anyway to <strong>insert duplicate rows</strong> in a query without altering the existing table (<em>two rows</em> for all subjects except for foreign language, which requires <em>three rows</em>).</p>
  <pre><code>select * from school_data
  
  student_name            subjects                class_date
    Joe                    Math                    10/1/2021
    Mike                  Science                  10/2/2021
    Eddie                 History                  10/3/2021
    Steve                 English                  10/4/2021
    John                 Foreign Language          10/5/2021
  </code></pre>
  <p>Requested:</p>
  <pre><code>student_name            subjects                class_date
    Joe                    Math                    10/1/2021
    Joe                    Math                    10/1/2021
    Mike                  Science                  10/2/2021
    Mike                  Science                  10/2/2021
    Eddie                 History                  10/3/2021
    Eddie                 History                  10/3/2021
    Steve                 English                  10/4/2021
    Steve                 English                  10/4/2021
    John                 Foreign Language          10/5/2021
    John                 Foreign Language          10/5/2021
    John                 Foreign Language          10/5/2021
  </code></pre>