title: Alter a Column Data Type Postgres
body: <p>Hey I have just started working on PostgreSQL, and I am wondering how can we change a column's data type, I tried the following command:</p>
  
  <pre><code>alter table tableName alter column columnName type timestamp with time zone;
  </code></pre>
  
  <p>However I got the following message:</p>
  
  <pre><code> column "columnName" cannot be cast to type timestamp with time zone
  </code></pre>
  
  <p>The current column's data type is int, and i would like to change it to timestamp</p>