Query shows 1 less than what's available in the #temp table

Question

So let's say #temp has 4 rows, the output will be 3(should be 4), if it has 1, then output will be 0.

I'm not quite sure what's going on. Wondering if anyone can tell by looking at the query.

SELECT TH.TnnNumber,
    CASE WHEN COUNT(DISTINCT TL.DiscountCodeID) > 1 THEN 'Varies, View Tnn' ELSE CAST(MAX(DC.Value) AS NVARCHAR(50)) END AS Discount,
    CASE WHEN TS.SpinID > 4 THEN 'Has Specifics, View Tnn' ELSE TS.Value END AS Spin,
    CASE WHEN COUNT(DISTINCT TL.Commission_HMM) > 1 THEN 'Varies, View Tnn' ELSE CAST(MAX(ISNULL(str(TL.Commission_HMM, 12), 'Default Comm')) AS NVARCHAR(50)) END AS Commission_HMM,
    CASE WHEN COUNT(DISTINCT TL.Commission) > 1 THEN 'Varies, View Tnn' ELSE CAST(MAX(ISNULL(str(TL.Commission, 12), 'Default Comm')) AS NVARCHAR(50)) END AS Commission,
    TL.TnnID
FROM [DBSERV].Tnn.DBO.Tnn_Header AS TH
LEFT JOIN [DBSERV].Tnn.DBO.Tnn_LINE AS TL
    ON TH.TnnID = TL.TnnID
LEFT JOIN [DBSERV].Tnn.DBO.Tnn_Spin AS TS
    ON TH.SpinID = TS.SpinID
LEFT JOIN [DBSERV].Tnn.DBO.Tnn_DiscountCode AS DC
    ON TL.DiscountCodeID = DC.DiscountCodeID
INNER JOIN #temp AS T
    ON T.Tnn = TH.TnnNumber
GROUP BY TH.TnnNumber,
    TS.SpinID,
    TS.Value,
    TL.TnnID

Required output:

+-----------+----------+-------------------------+----------------+--------------+-------+
| TnnNumber | Discount |          Spin           | Commission_HMM |  Commission  | TnnID |
+-----------+----------+-------------------------+----------------+--------------+-------+
|    902054 | 50-20-9  | Has Specifics, View Tnn | Default Comm   | Default Comm |  5855 |
|    907616 | 50-20-20 | Half                    | Default Comm   |            2 |  6111 |
|    910019 | 50-20-9  | Half                    | Default Comm   | Default Comm |  7015 |
|    915919 | 50-20-9  | Half                    | Default Comm   | Default Comm |  7015 |
+-----------+----------+-------------------------+----------------+--------------+-------+

Actual output:

+-----------+----------+-------------------------+----------------+--------------+-------+
| TnnNumber | Discount |          Spin           | Commission_HMM |  Commission  | TnnID |
+-----------+----------+-------------------------+----------------+--------------+-------+
|    902054 | 50-20-9  | Has Specifics, View Tnn | Default Comm   | Default Comm |  5855 |
|    907616 | 50-20-20 | Half                    | Default Comm   |            2 |  6111 |
|    910019 | 50-20-9  | Half                    | Default Comm   | Default Comm |  7015 |
+-----------+----------+-------------------------+----------------+--------------+-------+

Values in #temp

Tnn
902054
907616
910019
915919

Right join:

+-----------+----------+-------------------------+----------------+--------------+-------+
| TnnNumber | Discount |          Spin           | Commission_HMM |  Commission  | TnnID |
+-----------+----------+-------------------------+----------------+--------------+-------+
| NULL      | NULL     | NULL                    | Default Comm   | Default Comm | NULL  |
| 902054    | 50-20-9  | Has Specifics, View Tnn | Default Comm   | Default Comm | 5855  |
| 907616    | 50-20-20 | Half                    | Default Comm   |            2 | 6111  |
| 910019    | 50-20-9  | Half                    | Default Comm   | Default Comm | 7015  |
+-----------+----------+-------------------------+----------------+--------------+-------+

Answer 1

As your RIGHT JOIN query show your

[DBSERV].Tnn.DBO.Tnn_Header AS TH

Doesn't have the row with ID = 915919 that is why RIGHT JOIN return NULL and INNER JOIN return a row less

try

SELECT *
FROM [DBSERV].Tnn.DBO.Tnn_Header AS TH
WHERE TH.TnnNumber = 915919

Now you have to check how are you creating #temp and validate you are using the same ID related to Tnn_Header