title: View doesn't allow null value
body: <p>I have a view that show the data of several different object. </p>
  
  <pre><code>CREATE VIEW viewA AS
      SELECT
          fiel1, field2, field3, -- table 1
          field4, field5, field6, -- table 2
          field7, field8 -- table 3
      FROM table1 t1
         JOIN table2 t2 ON t1.t2id = t2.id
         JOIN table3 t3 ON t1.t3id = t3.id
  GO
  </code></pre>
  
  <p>My tables are the following :</p>
  
  <pre><code>CREATE TABLE table1 (
     id      int not null IDENTITY(1, 1),
     field1  int not null IDENTITY(1, 1),
     field2  int not null,
     field3  int not null,
     t2id    int, -- foreign key, is nullable
     t3id    int  -- foreign key, is nullable
  );
  
  CREATE TABLE table2 (
     id      int not null IDENTITY(1, 1),
     field4  int not null,
     field5 int not null,
     field6 varchar not null
  );
  
  CREATE TABLE table3 (
     id      int not null IDENTITY(1, 1),
     field7  int not null,
     field8 varchar not null
  );
  </code></pre>
  
  <p>When I populate table1 with some data and nothing in the t2id, the view is not populated with the data, even though the id itself is not mandatory. When I complete the fields and add some id in t2id, the data is correctly displayed. I tried to use the isnull function in <code>isnull(field7, null) as field7</code> but that doesn't change anything.</p>
  
  <p>So, is it possible to have a view that display null value, even if the field itself is not nullable but the references is ? (I also tried with the field nullable and it didn't work).</p>