title: Why is no default value generated/inserted?
body: <p>I have just altered a table <code>place</code> and it's column <code>claimed</code> like this:</p>
  
  <pre class="lang-sql prettyprint-override"><code>ALTER TABLE place
      ADD COLUMN IF NOT EXISTS claimed boolean NOT NULL DEFAULT false;
  </code></pre>
  
  <p>In phpPgAdmin I can see that it worked. Also all initial values are correctly set to <code>false</code>.</p>
  
  <p>Howerver, as I create a new record:</p>
  
  <pre><code>this.placeRepository.save(place);
  </code></pre>
  
  <p>I am getting:</p>
  
  <pre><code>ERROR: null value in column "claimed" violates not-null constraint
  </code></pre>
  
  <p>or as a whole:</p>
  
  <pre><code>2018-09-21 21:56:47.902  WARN 30087 --- [nio-8443-exec-9] o.h.engine.jdbc.spi.SqlExceptionHelper   : SQL Error: 0, SQLState: 23502
  2018-09-21 21:56:47.903 ERROR 30087 --- [nio-8443-exec-9] o.h.engine.jdbc.spi.SqlExceptionHelper   : ERROR: null value in column "claimed" violates not-null constraint
    Detail: Failing row contains (17, 2018-09-21 19:56:47.885, 2018-09-21 19:56:47.885, ChIJj15CRtukokcRcvSmyJCKGU4, 49.7759560000000008, 9.57715980000000044, Wertheim Village, Almosenberg, Wertheim, null).
  2018-09-21 21:56:47.908  INFO 30087 --- [nio-8443-exec-9] m.a.s.e.CustomRestExceptionHandler       : org.springframework.dao.DataIntegrityViolationException
  2018-09-21 21:56:47.908  INFO 30087 --- [nio-8443-exec-9] m.a.s.e.CustomRestExceptionHandler       : org.hibernate.exception.ConstraintViolationException
  </code></pre>
  
  <p>I don't see what's the problem here. So why is the default value not generated here? It seems to me Hibernate just tries to insert a <code>null</code> value?</p>
  
  <p>I think this should not matter but just to be sure I also added <code>nullable = false</code> in my Java code to the column of the entity class:</p>
  
  <pre><code>@Column(nullable = false)
  private Boolean claimed;
  </code></pre>