How to generate rows for missing homeworks? : <p>Suppose I have a table of students, the dates they completed their homework, and how they performed. For example: t1</p>

<pre><code>Name     Date        Result 
Carlos   2019-06-01  Average 
Carlos   2019-06-02  Outstanding 
Carlos   2019-06-03  Outstanding 
Ernesto  2019-06-01  Average 
Ernesto  2019-06-02  Average 
Ernesto  2019-06-03  Failed 
Miguel   2019-06-02  Average 
Miguel   2019-06-03  Average
Ashley   2019-06-01  Outstanding 
Ashley   2019-06-02  Outstanding
Eddie    2019-06-01  Failed 
Eddie    2019-06-03  Failed
</code></pre>

<p>As you can see from the table, there are no records for Miguel(2019-06-01), Ashley(2019-06-03), and Eddie(2019-06-02). In those scenarios, I would like to generate an extra row whenever there's a missing homework.</p>

<p>I would like to generate a new table like this:</p>

<pre><code>Name     Date        Result 
Carlos   2019-06-01  Average 
Carlos   2019-06-02  Outstanding 
Carlos   2019-06-03  Outstanding 
Ernesto  2019-06-01  Average 
Ernesto  2019-06-02  Average 
Ernesto  2019-06-03  Failed
Miguel   2019-06-01  Missing      --New row
Miguel   2019-06-02  Average 
Miguel   2019-06-03  Average
Ashley   2019-06-01  Outstanding 
Ashley   2019-06-02  Outstanding
Ashley   2019-06-03  Missing      --New row
Eddie    2019-06-01  Failed
Eddie    2019-06-02  Missing      --New row
Eddie    2019-06-03  Failed
</code></pre>

<p>Any clues?</p>

<p>Thanks guys!</p>
