title: Regex - Invalid regular expression: '(?:[v=)', no argument for repetition operator:?
body: <p>I have this query that I'm using in Snowflake:</p>
  <pre><code>Select *,
  case  WHEN REGEXP_SUBSTR(NAME, '(?:\[v=)') is not null THEN REGEXP_SUBSTR(NAME, '[[]v=([0-9]+)')
  else null
  end
  from my_table;
  </code></pre>
  <p>but when I try to run it, it tells me:</p>
  <blockquote>
  <p>Invalid regular expression: '(?:[v=)', no argument for repetition
  operator: ?</p>
  </blockquote>
  <p>but I've tested this out on regex101 <a href="https://regex101.com/r/WyQD8W/1" rel="nofollow noreferrer">here</a> and it looks like its working, I want to check for <code>[v=</code></p>
  <p>Edit: More insight into what I'm trying to find w. the regex, I have rows that look like this <code>test [v=123]</code>, <code>words [v=444]</code>, <code>more [v=532]</code> and I need to be able to look through each column and find if it has <code>[v=</code> and extract the numbers only</p>