title: Modify certain BSEG fields from customary structured table
body: <p>I'm trying to use following:</p>
  
  <pre><code>update bseg from zbseg
  </code></pre>
  
  <p>where tables are not from same length (<code>ZBSEG</code> is reduced version of <code>BSEG</code>).</p>
  
  <p>Whole idea is that <code>BSEG</code> is just an example, I have a loop where all cluster tables will be iterated, so everything should be dynamically. </p>
  
  <p>Table data from cluster is reduced to only several fields and copied to transparent table (data dictionary in new transparent table has primary keys + only few of the field of cluster) and afterwards data in DB will be modified and copied back via <code>UPDATE</code> to the cluster.</p>
  
  <pre><code>update bseg from zbseg
  </code></pre>
  
  <p>this statement updates the field values from <code>ZBSEG</code> but for the rest will not keep old values but rather puts initial values.</p>
  
  <p>I've tried even that:</p>
  
  <pre><code>SELECT *
  FROM bseg
  INTO TABLE gt_bseg.
  
  SELECT mandt bukrs belnr gjahr buzei buzid augdt
  FROM zbseg
  INTO CORRESPONDING FIELDS OF TABLE gt_bseg.
  </code></pre>
  
  <p>but it still overlaps those fields that are not considered in zbseg.</p>
  
  <p>Any statement that will update only certain range of fields extracted from <code>ZBSEG</code> not touching other <code>BSEG</code> fields?</p>
  
  <p><img src="https://i.stack.imgur.com/1ab9d.jpg" alt="IMAGE: Looping over original full length and short table"></p>