title: how to get all the words that start with a certain character in bigquery
body: <p>I have a text column in a bigquery table. Sample record of that column looks like -</p>
  
  <pre><code>with temp as 
  (
  select 1 as id,"as we go forward into unchartered waters it's important to remember we are all in this together. #united #community" as input
  union all
  select 2 , "US cities close bars, restaurants and cinemas #Coronavirus"
  )
  
  select *
  from temp
  </code></pre>
  
  <p>I want to extract all the words in this column that start with a <code>#</code> . later on I would like to get the frequency of these terms. How do I do this in BigQuery ?</p>
  
  <p>My output would look like - </p>
  
  <pre><code>id, word
  1, united
  1, community
  2, coronavirus
  </code></pre>