title: Fix must appear in the GROUP BY clause or be used in an aggregate function
body: <pre><code>select
      case
          when daftar ='sd' then kouta
      end as a,
      case
          when daftar = 'smp' then kouta
      end as b,
      case
          when daftar = 'sma' then kouta
      end as c
  from
      ajaran
  GROUP BY
      tahun
  </code></pre>
  
  <p>and result error </p>
  
  <blockquote>
    <p>[Err] ERROR:  column "ajaran.daftar" must appear in the GROUP BY
    clause or be used in an aggregate function LINE 1: select  case when
    daftar='sd' then kouta end as a,case when ...</p>
  </blockquote>
  
  <p>I'm trying same query in MySQL and no error and success grouping
  how to use group by in PostgreSQL?</p>
  
  <p>I want to group by <code>tahun</code>.</p>
  
  <p>This is my table.</p>
  
  <p><img src="https://i.stack.imgur.com/6un2P.jpg" alt="this my table"></p>