Select count of users without preferences

​

TABLE [dbo].[Users] (

    [Id]                            UNIQUEIDENTIFIER NOT NULL DEFAULT NEWID(),

    [FirstName]                     NVARCHAR (100)   NULL,

    [LastName]                      NVARCHAR (100)   NULL,

    [Phone]                         NVARCHAR (25)    NULL,

    [Email]                         NVARCHAR (255)   NULL    

);

​

​

TABLE [dbo].[UserPreferences] (

    [UserId]                     UNIQUEIDENTIFIER NOT NULL,

    [PrintReceipts]              BIT              NOT NULL CONSTRAINT DF_UserPreferences_PrintReceipts DEFAULT 0,    

    [UseTouchId]                 BIT              NULL    

);

​

Question:

select count(*) from dbo.Users u                                                                                    --Row count: 1000

select count(*) from dbo.UserPreferences p                                                                          --Row count: 900

select count(*) from dbo.Users u left join dbo.UserPreferences p on p.userid = u.id                                 --Row count: 

select count(*) from dbo.Users u left join dbo.UserPreferences p on p.userid = u.id and p.userid IS NULL            --Row count: 

select count(*) from dbo.Users u left join dbo.UserPreferences p on p.userid = u.id where p.userid IS NULL          --Row count: 

select count(*) from dbo.Users u left join dbo.UserPreferences p on p.userid = u.id where p.PrintReceipts IS NULL   --Row count: 

select count(*) from dbo.Users u left join dbo.UserPreferences p on p.userid = u.id where p.UseTouchId IS NULL      --Row count: