title: How to find Negative maximum and positive minimum in Oracle?
body: <p>I have a column of type <code>number</code>. It has both positive and negative values. I need to get 4 values : Positive Maximum,Positive Minimum, Negative Maximum,Negative Minimum:</p>
  
  <p>a)To get Positive Maximum : I can use <a href="http://sqlfiddle.com/#!4/6aa70/4" rel="nofollow">Check out the Fiddle</a></p>
  
  <pre><code>select max(cola) from test;
  </code></pre>
  
  <p>b)To get Negative Minimum: I can use <a href="http://sqlfiddle.com/#!4/6aa70/4" rel="nofollow">Check out the Fiddle</a></p>
  
  <pre><code>select min(cola) from test;
  </code></pre>
  
  <p>I have two question here:</p>
  
  <p>1)Now i'm not sure how to get the other two values. Guide me to get that</p>
  
  <p>2)Meanwhile while trying this i got another doubt. When i have some column of type <code>varchar2</code> and it has numbers as value. I'm performing the above operation in this column. Positive maximum is same as above. But Negative minimum is quiet weird. <a href="http://sqlfiddle.com/#!4/6aa70/5" rel="nofollow">Check Fiddle Here</a> .Why there is no proper implicit conversion is taking place here. Somebody pls explain the reason behind this?</p>