title: How to change MySQL column definition?
body: <p>I have a mySQL table called test:</p>
  
  <pre><code>create table test(
      locationExpect varchar(120) NOT NULL;
  );
  </code></pre>
  
  <p>I want to change the locationExpect column to:</p>
  
  <pre><code>create table test(
      locationExpect varchar(120);
  );
  </code></pre>
  
  <p>How can it be done quickly?</p>