title: Django: filtering on `DecimalField` doesn't work well?
body: <p>This is my <code>model</code>:</p>
  
  <pre><code>class Tick(BaseModel):
      .
      .
      trade_coin_volume = models.DecimalField(
          max_digits=15,
          decimal_places=8,
      )
      trade_price = models.DecimalField(
          max_digits=15,
          decimal_places=8,
      )
      .
      .
  </code></pre>
  
  <p>I print out <code>trade_coin_volume</code> of all <code>Tick</code> objects:</p>
  
  <pre><code>In [9]: for tick in Tick.objects.all():
     ...:     print(tick.trade_coin_volume)
     ...:
  0.02120853
  0.05000000
  0.26628998
  0.19354556
  0.32299392
  0.72599405
  0.05955935
  0.05354201
  0.00767441
  0.05101970
  0.20967645
  0.10000001
  0.00500000
  0.00899999
  0.15274410
  0.32104315
  0.00300000
  0.22695384
  0.05000000
  0.13894616
  0.00631414
  0.07967759
  0.28592241
  0.23765636
  0.05777923
  0.08883787
  0.05000000
  0.14535185
  </code></pre>
  
  <p>As you can see above, there are some <code>0.05000000</code> values.</p>
  
  <p>But when I filter <code>Tick</code> objects based on this field,</p>
  
  <pre><code>In [11]: Tick.objects.filter(trade_coin_volume=0.05)
  Out[11]: &lt;QuerySet []&gt;
  
  In [12]: Tick.objects.filter(trade_coin_volume=0.05000000)
  Out[12]: &lt;QuerySet []&gt;
  </code></pre>
  
  <p>It doesn't show anything!</p>
  
  <p>Why does it happen?</p>