title: SQL GROUP BY total price of every week of the year
body: <p>OK, so i am doing some Access here and i cant figure it out, already tried a lot by searching but nothing really comes close. And i am hoping some of you knows what to do.</p>
  
  <p>I have some tables on my database (just a simple one for school)</p>
  
  <p>Table of products</p>
  
  <pre><code>Type    Price   Color  Height Model
  --------------------------------------------
  KL47    69      B      150    Dames Normal Model
  VRS02   73      W      170    Heren Smal Model`
  </code></pre>
  
  <p>Table of copies - products</p>
  
  <pre><code>Copienr Type
  ------------------------
  K664    KL47
  T553    KL47
  V3553   VRS02
  V7744   VRS02
  V9941   VRS02
  </code></pre>
  
  <p>Table of custumers</p>
  
  <pre><code>Customrnr   Companyname  Adress
  -----------------------------------------
  1           Jiver        Posthoorn 27
  2           Veco         Weebosserweg 21
  3           V&amp;D          Omabakfietsjes 74
  </code></pre>
  
  <p>And at last a table for checking witch customer is renting witch product</p>
  
  <pre><code>Rentnr  Customernr  Copienr Date-from   Date-Till
  -------------------------------------------------------
  5       3           K664    11/5/2014   11/29/2014
  6       3           T553    10/7/2014   12/13/2014
  7       3           V3553   11/18/2014  12/19/2014
  8       3           V3553   4/8/2015    8/12/2015
  9       3           V7744   4/8/2015    7/8/2015
  10      3           T553    5/4/2015    6/8/2015
  </code></pre>
  
  <p>Now I want a table of all products that company V&amp;D rented for this year so far.
  Group by total price of every week.</p>
  
  <p>I have this so far:</p>
  
  <pre><code>SELECT t.typen, c.copienr, date-from, date-till, companyname, price
  FROM typen t, copies c, rented-vieuw r, customers c
  WHERE bedrijfsnaam = 'V&amp;D'
  AND c.customernr = r.customernr
  AND r.copienr = c.copienr
  AND c.type = t.type
  AND date-from &gt;= #1/1/2015#;
  </code></pre>
  
  <p>Further on, for grouping by total price for eatch week i tried a lot. Thinks that doenst even make any sence but I cant figure it out.
  I hope you can help my out. Thanks!</p>
  
  <p>Edit: The price in the table products is the cost for renting the product / weak***</p>