title: Violation on primary key with multiple keys in table
body: <pre><code>CREATE TABLE parameters (
    tag_id BIGINT,
    id NVARCHAR(255),
    idx NVARCHAR(255),
    primary key (tag_id, idx)
  );
  
  CREATE TABLE tag
      ([oid] int, [Name] varchar(1))
  ;
  
  INSERT INTO tag
      ([oid], [Name])
  VALUES
      (1, 'A'),
      (2, 'B'),
      (3, 'C'),
      (4, 'D')
  ;
  
  INSERT parameters (tag_id, id, idx)
  SELECT tag.oid, id.a, idx.a
  FROM 
      ( VALUES (1), (0), ('A'), (2) ) AS id(a), 
      ( VALUES ('a'), ('b'), ('c'), ('d') ) AS idx(a), 
      tag
  </code></pre>
  
  <p>This should be output:</p>
  
  <pre><code>tag_id              id              idx     
  ______________________________________________
  1                   1               a
  1                   0               b
  1                   A               c
  1                   2               d
  2                   1               a
  2                   0               b
  2                   A               c
  2                   2               d
  3                   1               a
  3                   0               b
  3                   A               c
  3                   2               d
  4                   1               a
  4                   0               b
  4                   A               c
  4                   2               d
  </code></pre>
  
  <p>Below is the error which I am getting:</p>
  
  <blockquote>
    <p>Cannot insert duplicate key in object 'tag_parameters'. The duplicate
    key value is (1, a).</p>
  </blockquote>
  
  <p>Why if I have only one combination (1, a). The next one is (2, a).</p>