title: How to perform MySQL spatial buffer function successfully?
body: <p>Does anyone ever use MySQL spatial buffer function successfully?
  I've read the documentation here: <a href="http://dev.mysql.com/doc/refman/5.0/en/functions-that-create-new-geometries-from-existing-ones.html#function_buffer" rel="nofollow">http://dev.mysql.com/doc/refman/5.0/en/functions-that-create-new-geometries-from-existing-ones.html#function_buffer</a></p>
  
  <p>As stated in the documentation, buffer function has 2 parameters. The first one is geometry typed, the second one is distance.</p>
  
  <p>I've try to make a geometry variable</p>
  
  <pre><code>mysql&gt; set @g1 = geomfromtext('POINT(1 1)');
  Query OK, 0 rows affected (0.00 sec)
  </code></pre>
  
  <p>Then, to ensure that my variable is correctly set, I perform a query. If the variable not correctly set, such a query will return NULL. In this case, it is confirmed that my variable is correctly set</p>
  
  <pre><code>mysql&gt; select astext(@g1);
  +-------------+
  | astext(@g1) |
  +-------------+
  | POINT(1 1)  |
  +-------------+
  1 row in set (0.00 sec)
  </code></pre>
  
  <p>I run a query to select a buffer as stated in documentation</p>
  
  <pre><code>mysql&gt; select astext(buffer(@g1, 5));
  ERROR 1305 (42000): FUNCTION module_devel.buffer does not exist
  </code></pre>
  
  <p>Do I miss something here?</p>
  
  <p><strong>EDIT</strong> Sorry guys, I think I miss this:</p>
  
  <blockquote>
    <p>12.17.5.3.2. Spatial Operators</p>
    
    <p>OpenGIS proposes a number of other functions that can produce
    geometries. They are designed to implement spatial operators.
    <strong>These functions are not implemented in MySQL.</strong></p>
  </blockquote>