title: MySQL - How to search a single character with fulltext index
body: <p>We have an InnoDB table <code>post</code>, and create a FULLTEXT index on two column <code>title</code> &amp; <code>content</code> with <strong>ngram</strong> parser.<br>
  Most of the data is Chinese characters, but contains some Japanese and English characters.  </p>
  
  <p>We use <strong>MySQL 8.0.15</strong> and I already set the <code>innodb_ft_min_token_size</code> value to 1. Now I want to do something like this:  </p>
  
  <pre><code>SELECT * FROM `post` WHERE MATCH (`title`, `content`) AGAINST ('e');
  
  expected result:
  title          content
  ------------------------
  Food           noodle
  </code></pre>
  
  <p>or real-case example:</p>
  
  <pre><code>SELECT * FROM `post` WHERE MATCH (`title`, `content`) AGAINST ('麵');
  
  expected result:
  title           content
  ------------------------
  本週推薦美食     到底該吃飯還是麵
  </code></pre>
  
  <p>It doesn't make sense in English, but sometime a single character has meaning in Chinese.<br>
  However, when I search a single character, it returns me an empty set. Only for some special characters, like Japanese character <code>す</code> and <code>し</code>, return a few results in boolean mode (it doesn't return all rows that contain the character).  </p>
  
  <p>I tried to use wildcard operator and query in boolean mode, but it is not working when the searching character is the last character of a sentence.  </p>
  
  <p>I also tried to set <code>ngram_token_size</code> to 1. It presents a strange result: all general search queries return nothing and those special characters still work as mentioned above. But if I search those special characters with <code>WITH QUERY EXPANSION</code> syntax, this time it will return more results than boolean mode (I'm not sure if these are all rows that contain the character).  </p>
  
  <p>Is it possible to use full-text search with a single character?</p>