title: How to join strings in a table in kdb?
body: <p>I would like to join string in kdb but didn't work well. This is the data:</p>
  
  <pre><code>tab:([]service:`CS`CS.US`CS.US_ABC;y:1 2 3)
  
  
  `CS 1
  `CS.US  2
  `CS.US_ABC  3
  </code></pre>
  
  <p>I would like to add :0 and :primary depending on the given parameter. 0 is working now</p>
  
  <pre><code>update service:`$(((string[service],'(":"))),'("C"$string 0)) from tab
  </code></pre>
  
  <p>If I would like the data to become </p>
  
  <pre><code>`CS:primary 1
  `CS.US:primary  2
  `CS.US_ABC:primary  3
  </code></pre>
  
  <p>and the primary is either string or symbol, how could I join?</p>
  
  <p>I am parameterizing the 0 and primary.</p>
  
  <p>Currently, 0 works as follows</p>
  
  <pre><code>update service:`$(((string[service],'(":"))),'( "0")) from tab
  </code></pre>
  
  <p>but "primary" is not working</p>
  
  <pre><code>update service:`$(((string[service],'(":"))),'( "primary")) from tab
  </code></pre>