title: Return strings which contains number on specific position
body: <p>I am basic on SQL queries and I need some help.
  I have to select all string values which contains number e.g. 7 only on specific position in that string.</p>
  <p>For example:
  I have string: <em>987654321</em> and if on position <em>3</em> I will have number <em>7</em>, then it should be selected.
  So in example this string will be selected, because on 3rd position I have number 7.</p>
  <p>Is there any SQL function for that, or something which could help me?</p>
  <p>EDIT:</p>
  <h3>Example table</h3>
  <pre><code>      TABLE
  Numbers      Value
  987654321    1
  123456789    2
  789009871    3
  654321092    4
  847949372    5
  </code></pre>
  <h3>Output:</h3>
           
  <pre><code>       TABLE
  Numbers      Value
  987654321    1
  847949372    5
  </code></pre>
  <h3>Statement:</h3>
  <pre><code>SELECT table.numbers
  FROM TABLE
  WHERE substr(table.numbers,3,1)='7' &lt;--- what to do here? ---&gt;
  </code></pre>
  <p>Many thanks in advance.</p>