title: MySQL boolean full text search not working as expected
body: <p>I have a table of chemical substances, called <code>substances</code>. I'm trying to impelement a search facility making use of MySQL's <a href="https://dev.mysql.com/doc/refman/5.7/en/fulltext-natural-language.html" rel="nofollow noreferrer">full text natural language</a> capabilities.</p>
  <p>I have run the following to allow such commands to work on my <code>substances</code> table on the <code>name</code> column:</p>
  <pre><code>ALTER TABLE substances ADD FULLTEXT(`name`);
  </code></pre>
  <p>If I run the following command it gives me any results which contain either the word &quot;Chromium&quot; or &quot;Trioxide&quot; as expected:</p>
  <pre><code>SELECT * FROM substances WHERE MATCH (`name`) AGAINST ('Chromium Trioxide' IN NATURAL LANGUAGE MODE);
  </code></pre>
  <p>However what I want to do is find only rows that contain &quot;Chromium Trioxide&quot;, even if there are characters in between them (e.g. &quot;Chromium (VI) Trioxide&quot;). My understanding is that using a <code>+</code> before each word would do this:</p>
  <pre><code>SELECT * FROM substances WHERE MATCH (`name`) AGAINST ('+Chromium +Trioxide' IN NATURAL LANGUAGE MODE);
  </code></pre>
  <p>But it gives me the same results as the original query - i.e. anything that contains either &quot;Chromium&quot; or &quot;Trioxide&quot; but not both.</p>
  <p>Where am I going wrong?  I've read up on Boolean Full Text searches (<a href="https://dev.mysql.com/doc/refman/5.7/en/fulltext-boolean.html" rel="nofollow noreferrer">https://dev.mysql.com/doc/refman/5.7/en/fulltext-boolean.html</a>) but the only info I found was to include the <code>+</code> before each keyword.</p>
  <p>MySQL version is 5.7.9 and the table is MyISAM.</p>