title: MySQL Workbench Error Code: 3819 when adding check constraint
body: <p><strong>Attributes</strong></p>
  <p><a href="https://i.stack.imgur.com/1bexH.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/1bexH.jpg" alt="enter image description here" /></a></p>
  <p>I am trying to add a constraint check for an attribute. But I am getting errors. I have tried in upper and lower case. The name is correct as you can see from the image.  What is going wrong here?</p>
  <pre><code>ALTER TABLE supplier ADD CONSTRAINT CHK_supplier_size CHECK (supplier_size&gt;= 15);
  </code></pre>
  <blockquote>
  <p>0 6   09:35:38    ALTER TABLE supplier ADD CONSTRAINT CHK_supplier_size
  CHECK (supplier_size&gt;= 15)    Error Code: 3819. Check constraint
  'CHK_supplier_size' is violated.  0.735 sec</p>
  </blockquote>