title: MariaDB: ALTER TABLE syntax to add a FOREIGN KEY?
body: <p>what'S wrong with the following statement?</p>
  
  <pre><code>ALTER TABLE submittedForecast
    ADD CONSTRAINT FOREIGN KEY (data) REFERENCES blobs (id);
  </code></pre>
  
  <p>The error message I am getting is</p>
  
  <pre><code>Can't create table `fcdemo`.`#sql-664_b` (errno: 150 "Foreign key constraint is incorrectly formed")
  </code></pre>