SQL COUNT NULL values
<p>I am trying to find the Playlist(s) with 10 or more tracks that have NULL values in the Composer column. </p>

<p>Here are the tables</p>

<pre><code>CREATE TABLE [Playlist]
(
[PlaylistId] INTEGER  NOT NULL,
[Name] NVARCHAR(120),
CONSTRAINT [PK_Playlist] PRIMARY KEY  ([PlaylistId])
);

CREATE TABLE [PlaylistTrack]
(
[PlaylistId] INTEGER  NOT NULL,
[TrackId] INTEGER  NOT NULL,
CONSTRAINT [PK_PlaylistTrack] PRIMARY KEY  ([PlaylistId], [TrackId]),
FOREIGN KEY ([PlaylistId]) REFERENCES [Playlist] ([PlaylistId]) 
    ON DELETE NO ACTION ON UPDATE NO ACTION,
FOREIGN KEY ([TrackId]) REFERENCES [Track] ([TrackId]) 
    ON DELETE NO ACTION ON UPDATE NO ACTION
);

CREATE TABLE [Track]
(
[TrackId] INTEGER  NOT NULL,
[Name] NVARCHAR(200)  NOT NULL,
[AlbumId] INTEGER,
[MediaTypeId] INTEGER  NOT NULL,
[GenreId] INTEGER,
[Composer] NVARCHAR(220),
[Milliseconds] INTEGER  NOT NULL,
[Bytes] INTEGER,
[UnitPrice] NUMERIC(10,2)  NOT NULL,
CONSTRAINT [PK_Track] PRIMARY KEY  ([TrackId]),
FOREIGN KEY ([AlbumId]) REFERENCES [Album] ([AlbumId]) 
    ON DELETE NO ACTION ON UPDATE NO ACTION,
FOREIGN KEY ([GenreId]) REFERENCES [Genre] ([GenreId]) 
    ON DELETE NO ACTION ON UPDATE NO ACTION,
FOREIGN KEY ([MediaTypeId]) REFERENCES [MediaType] ([MediaTypeId]) 
    ON DELETE NO ACTION ON UPDATE NO ACTION
)
</code></pre>

<p>Here is what I have so far. I think the query logic is good but is this the correct way to count up null values?</p>

<pre><code>SELECT P.PlaylistId, P.name
FROM Playlist P
    JOIN PlaylistTrack pt ON p.PlaylistId = pt.PlaylistId
    JOIN Track t ON pt.TrackId = t.TrackId
GROUP BY p.PlaylistId
HAVING COUNT(t.Composer IS NULL) &gt;=10;
</code></pre>