title: PostgreSQL `HINT: You will need to rewrite or cast the expression.` on update of a column with type POINT
body: <p>I am using PostgreSQL 9.1 with PostGIS 2.0.1.<br/></p>
  
  <p>The type of column <code>location</code> is <code>point</code>. type of <code>latitude</code> and <code>longitude</code> double precision.</p>
  
  <p>Why is this update statement </p>
  
  <pre><code>update list_of_location SET location = ST_SetSRID(ST_MakePoint(longitude,latitude), 4326);
  </code></pre>
  
  <p>returning </p>
  
  <pre><code>LINE 1: update list_of_location SET location = ST_SetSRID(ST_MakePoint(longit...
                                                 ^
  HINT:  You will need to rewrite or cast the expression.
  </code></pre>