title: How to fill the empty record per group using mysql?
body: <p>I am trying to handle the sql query in order to get what I want.</p>
  <p>Below is the schema of the table.</p>
  <pre><code>CREATE TABLE MY_LOG (
      RANKING      VARCHAR(20)   
    , DAYOFWEEK      VARCHAR(10) 
    , MENU     VARCHAR(10)   
  )
  
  </code></pre>
  <p>I have inserted some values and it looks like as below.</p>
  <pre><code>Ranking   DAYOFWEEK   MENU
  1         MONDAY      PIZZA 
  2         MONDAY      ICE CREAM
  3         MONDAY      CHICKEN
  4         MONDAY      RICE
  5         MONDAY      BREAD
  1         TUESDAY      PIZZA 
  2         TUESDAY      ICE CREAM
  3         TUESDAY      CHICKEN
  4         TUESDAY      RICE
  1         WEDNESDAY      PIZZA 
  2         WEDNESDAY      ICE CREAM
  3         WEDNESDAY      CHICKEN
  </code></pre>
  <p>As you can see, for each day of week, the ranking is shown with its menu.
  However, for Tuesday and Wednesday they have only four and three records.
  So I would like to insert the blank record as shown below.</p>
  <pre><code>Ranking   DAYOFWEEK   MENU
  1         MONDAY      PIZZA 
  2         MONDAY      ICE CREAM
  3         MONDAY      CHICKEN
  4         MONDAY      RICE
  5         MONDAY      BREAD
  1         TUESDAY      PIZZA 
  2         TUESDAY      ICE CREAM
  3         TUESDAY      CHICKEN
  4         TUESDAY      RICE
  5         -            -
  1         WEDNESDAY      PIZZA 
  2         WEDNESDAY      ICE CREAM
  3         WEDNESDAY      CHICKEN
  4         -              -
  5         -              -
  </code></pre>
  <p>I have tried to resolve this issue but failed.
  How to achieve this?</p>