title: MySQL update column value using CAST
body: <p>I have simple table (with wrong formatted data):</p>
  <pre><code>+========+
  | weight |
  +========+
  | 100г   |
  +--------+
  | 200 г  |
  +--------+
  | 300гр  |
  +--------+
  | 400 гр |
  +--------+
  | 500г.  |
  +--------+
  </code></pre>
  <p>I can apply format to data when I do select:</p>
  <pre><code>SELECT CONCAT((weight + 0), ' г') formatted FROM t;
  
  +===========+
  | formatted |
  +===========+
  | 100 г     |
  +-----------+
  | 200 г     |
  +-----------+
  | 300 г     |
  +-----------+
  | 400 г     |
  +-----------+
  | 500 г     |
  +-----------+
  </code></pre>
  <p>Now I try to update data using above format:</p>
  <pre><code>UPDATE t SET weight = CONCAT((weight + 0), ' г');
  </code></pre>
  <p>But got the error:</p>
  <blockquote>
  <p>Truncated incorrect DOUBLE value: '200 г'</p>
  </blockquote>
  <p><a href="https://sqlize.online/sql/mysql57/6c2a657320851868415a09fb8bddb607/" rel="nofollow noreferrer">Here the fiddle</a></p>