title: Postgresql UPDATE query works on Windows but not on Ubuntu
body: <p>The following query executed on postgresql v10.3 running on windows works as expected. Suppose the fees_balance was 10000 before running the query, the query below gives back 17000:</p>
  
  <pre><code>UPDATE tbl_classes SET 
  fees_balance=T2.fees_balance + 7000
  FROM tbl_classes T2 WHERE CAST(tbl_classes.mobile_number AS TEXT)
  LIKE '%71000001' RETURNING tbl_classes.fees_balance;
  </code></pre>
  
  <p>Now the same query executed on postgresql v10.1 running on ubuntu 18.04 gives -7000! Is this a bug in postgresql on ubuntu or am I missing something? Kindly help</p>