title: How to insert null in column array datatype in ksql
body: <p>I am creating a stream where data type is Array. a null value comes so handle this i am creating another stream on top of previous stream, and giving a case like if its null put []. but its not working.</p>
  
  <p>i have tried [],{},[0],0 in cases.</p>
  
  <pre><code>CREATE STREAM stream1
  (
  id VARCHAR,
  tags ARRAY&lt;INT&gt;, 
  feed_id VARCHAR,
  status INT,
  updated_at VARCHAR
  )
  WITH (kafka_topic='origin_topic', value_format='JSON');
  
  Create Stream stream2 AS 
  select  
  id AS id,
  case when tags is NULL THEN [] END ELSE tags END as tags,
  case when feed_id is NULL THEN '0' ELSE feed_id END as feed_id,
  case when status is NULL THEN 0 ELSE status END as status,
  case when updated_at is NULL THEN '0' ELSE updated_at END as 
  updated_at
  from stream1 PARTITION BY id;
  </code></pre>