title: Postgresql - How do I extract the first occurence of a substring in a string using a regular expression pattern?
body: <p>I am trying to extract a substring from a text column using a regular expression, but in some cases, there are multiple instances of that substring in the string. </p>
  
  <p>In those cases, I am finding that the query does not return the first occurrence of the substring. Does anyone know what I am doing wrong? </p>
  
  <p>For example:</p>
  
  <p>If I have this data:</p>
  
  <pre><code>create table data1
  (full_text text, name text);
  
  insert into data1 (full_text)
  values ('I 56, donkey, moon, I 92')
  </code></pre>
  
  <p>I am using </p>
  
  <pre><code>UPDATE data1
  SET name = substring(full_text from '%#"I ([0-9]{1,3})#"%' for '#')
  </code></pre>
  
  <p>and I want to get <code>'I 56'</code> not <code>'I 92'</code></p>