title: accessing second element in regexp_matches array
body: <p>I have a table with a field that has strings like this: </p>
  
  <blockquote>
    <p>US 19;PA 65</p>
  </blockquote>
  
  <p>I need to split this out into four new fields like:</p>
  
  <blockquote>
    <p>'US ','19','PA','65'</p>
  </blockquote>
  
  <p>regexp_matches seems to be the ticket. I can use the following statements to extract 'US' into one field and '19' into another.</p>
  
  <pre><code>UPDATE osm_motorway SET shieldcl1 = (regexp_matches(ref, '^[A-Z]+', 'i'))[1];
  
  UPDATE osm_motorway SET shieldlbl1 = (regexp_matches(ref, '\d+', 'i'))[1];
  </code></pre>
  
  <p>But I can't get 'PA' and '65' into their own fields with the following. They return empty:</p>
  
  <pre><code>UPDATE osm_motorway SET shieldcl2 = (regexp_matches(ref, '^[A-Z]+', 'i'))[2];
  
  UPDATE osm_motorway SET shieldlbl2 = (regexp_matches(ref, '\d+', 'i'))[2];
  </code></pre>
  
  <p>How do I access the second match with regexp_matches?</p>