title: I need to create a null value in SQL
body: <p>I am tasked to create a column with a null value but I got an error.</p>
  <pre><code>SELECT * FROM test.Persons
  ALTER TABLE Persons
  ADD mark_percentage FLOAT
  </code></pre>
  <p>This is my error.</p>
  <blockquote>
  <p>12:32:47 use database test ALTER TABLE PERSONS ADD MARKS float SELECT * FROM test.Persons Error Code: 1064. You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'database test ALTER TABLE PERSONS ADD MARKS float SELECT * FROM test.Persons' at line 1 0.063 sec</p>
  </blockquote>