[#1768] NullPointerException when DAO.fetchOne() returns no record

jOOQ-test/src/org/jooq/test/_/testcases/DaoTests.java

@@ -94,6 +94,10 @@ extends BaseTest<A, AP, B, S, B2S, BS, L, X, DATE, BOOL, D, T, U, I, IPK, T658,
         assertEquals(2, TAuthorDao().count());
         assertEquals(2, TAuthorDao().findAll().size());
 
+        // [#1768] Unknown records should return null
+        assertNull(TAuthorDao().findById(3));
+        assertNull(TAuthorDao().fetchOne(TAuthor_ID(), 3));
+
         AP id1 = TAuthorDao().findById(1);
         assertEquals(1, on(id1).get("id"));
         assertEquals("George", on(id1).get("firstName"));

jOOQ/src/main/java/org/jooq/impl/DAOImpl.java

@@ -222,10 +222,11 @@ public abstract class DAOImpl<R extends UpdatableRecord<R>, P, T> implements DAO
 
     @Override
     public final <Z> P fetchOne(Field<Z> field, Z value) {
-        return create.selectFrom(table)
-                     .where(field.equal(value))
-                     .fetchOne()
-                     .into(type);
+        R record = create.selectFrom(table)
+                         .where(field.equal(value))
+                         .fetchOne();
+
+        return record == null ? null : record.into(type);
     }
 
     @Override