title: creating a custom column from joining two tables
body: <p>I am terrible with sub queries if that is what i need to do. First let me show you a preview of my tables and what i'm trying to do.</p>
  
  <p><img src="https://i.stack.imgur.com/LF6kR.png" alt="enter image description here"></p>
  
  <p>this is the result i want at the end:</p>
  
  <pre><code>business.name
  reviews_count (total count, matching the current queries business_id)
  where the b.industry_id matches 7
  </code></pre>
  
  <p>This is what i'm trying but i feel stuck and dont know how to match the total count, let me explain:</p>
  
  <pre><code>select
  b.name,
  reviews_count as (select count(*) as count from reviews where business_id = b.business_id),
  from business as b
  left join reviews as r
  on r.business_id = b.id
  where b.industry_id = 7
  </code></pre>
  
  <p>the sub query business_id needs to match the the current businesses id that is being run. Hope i made sense. ( reviews_count doesnt exist, i just made it up to use when i output)</p>