title: how to get week average from month in mysql?
body: <p>i have day, month, year, value columns in one table, here i need to get every week average value in one month.
  how to get that. please help me regarding this. </p>
  
  <pre><code>select avg(value) from table group by month 
  </code></pre>
  
  <p>gives month average.</p>
  
  <pre><code>select avg(value) from table group by day
  </code></pre>
  
  <p>gives day average.
  but how to get week average from month field.</p>