title: "Invalid character" error with Oracle11g, potentially thrown by _?
body: <p>So I am using Oracle SQL, looking to answer this question:
  <em>&quot;4. (10 Points) List all customers who are ordering equipment whose description begins with ‘tennis’ or ‘volleyball’. List the Customer number, Stock number, and Description. Do not repeat any rows.&quot;</em></p>
  <p>With this query:</p>
  <pre><code>SELECT c.customer_num, s.stock_num, s.description
  FROM customer c, stock s
  WHERE s.description LIKE %tennis%
  OR s.description LIKE %volleyball%
  GROUP BY c.customer_num;
  </code></pre>
  <p>The customer table schema is:
  <a href="https://i.stack.imgur.com/stnSN.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/stnSN.png" alt="customer_table_schema" /></a></p>
  <p>And the stock table schema is:
  <a href="https://i.stack.imgur.com/SLz01.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/SLz01.png" alt="stock_table_schema" /></a></p>
  <p>My error looks like this:</p>
  <p><a href="https://i.stack.imgur.com/xWZns.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/xWZns.png" alt="underscore_error" /></a></p>
  <p>It looks like SQL doesn't like the &quot;_&quot; character? But I ran my first query (which included underscores) with no issues. I tried adding parentheses and re-formatting the query but I have to use the underscore since that's what the table column name is. I haven't been able to find anything online that talks about this error. Any ideas as to what's going on here? Or any troubleshooting techniques I could try?</p>
  <p>Thank you!</p>