SQL Server Subquery Return Error - sql

Question

When I try to execute my statements, I get an error that returns "Subquery returned more than 1 value. Not allowed...," you know the rest. I'm not good with subqueries, in fact it's guessing with trial and error sometimes until I see the result I'm trying to gather. Can anyone explain to me the issue of why it's returning with this error?
I'm trying to return the score for one person's game before moving on to return all players from the same game.
The file is here if the data is relevant: SQL File
SELECT
TP.intPlayerID
,TP.strLastName + ', ' + TP.strFirstName AS strPlayerName
,TG.*
,TR.intGameID
,(
SELECT
CASE WHEN Game.F1S1 = 10 and Game.F2S1 = 10 THEN 20 + Game.F3S1
WHEN Game.F1S1 = 10 and Game.F2S1 < 10 THEN 10 + Game.F2S1 + Game.F2S2
WHEN Game.F1S1 + Game.F1S2 = 10 THEN 10 + Game.F2S1
ELSE Game.F1S1 + Game.F1S2
END
+
CASE WHEN Game.F2S1 = 10 and Game.F3S1 = 10 THEN 20 + Game.F4S1
WHEN Game.F2S1 = 10 and Game.F3S1 < 10 THEN 10 + Game.F3S1 + Game.F3S2
WHEN Game.F2S1 + Game.F2S2 = 10 THEN 10 + Game.F3S1
ELSE Game.F2S1 + Game.F2S2
END
+
CASE WHEN Game.F3S1 = 10 and Game.F4S1 = 10 THEN 20 + Game.F5S1
WHEN Game.F3S1 = 10 and Game.F4S1 < 10 THEN 10 + Game.F4S1 + Game.F4S2
WHEN Game.F3S1 + Game.F3S2 = 10 THEN 10 + Game.F4S1
ELSE Game.F3S1 + Game.F3S2
END
+
CASE WHEN Game.F4S1 = 10 and Game.F5S1 = 10 THEN 20 + Game.F6S1
WHEN Game.F4S1 = 10 and Game.F5S1 < 10 THEN 10 + Game.F5S1 + Game.F5S2
WHEN Game.F4S1 + Game.F4S2 = 10 THEN 10 + Game.F5S1
ELSE Game.F4S1 + Game.F4S2
END
+
CASE WHEN Game.F5S1 = 10 and Game.F6S1 = 10 THEN 20 + Game.F7S1
WHEN Game.F5S1 = 10 and Game.F6S1 < 10 THEN 10 + Game.F6S1 + Game.F6S2
WHEN Game.F5S1 + Game.F5S2 = 10 THEN 10 + Game.F6S1
ELSE Game.F5S1 + Game.F5S2
END
+
CASE WHEN Game.F6S1 = 10 and Game.F7S1 = 10 THEN 20 + Game.F8S1
WHEN Game.F6S1 = 10 and Game.F7S1 < 10 THEN 10 + Game.F7S1 + Game.F7S2
WHEN Game.F6S1 + Game.F6S2 = 10 THEN 10 + Game.F7S1
ELSE Game.F6S1 + Game.F6S2
END
+
CASE WHEN Game.F7S1 = 10 and Game.F8S1 = 10 THEN 20 + Game.F9S1
WHEN Game.F7S1 = 10 and Game.F8S1 < 10 THEN 10 + Game.F8S1 + Game.F8S2
WHEN Game.F7S1 + Game.F7S2 = 10 THEN 10 + Game.F8S1
ELSE Game.F7S1 + Game.F7S2
END
+
CASE WHEN Game.F8S1 = 10 and Game.F9S1 = 10 THEN 20 + Game.F10S1
WHEN Game.F8S1 = 10 and Game.F9S1 < 10 THEN 10 + Game.F9S1 + Game.F9S2
WHEN Game.F8S1 + Game.F8S2 = 10 THEN 10 + Game.F9S1
ELSE Game.F8S1 + Game.F8S2
END
+
CASE WHEN Game.F9S1 = 10 and Game.F10S1 = 10 THEN 20 + Game.F10S2
WHEN Game.F9S1 = 10 and Game.F10S1 < 10 THEN 10 + Game.F10S1 + Game.F10S2
WHEN Game.F9S1 + Game.F9S2 = 10 THEN 10 + Game.F10S1
ELSE Game.F9S1 + Game.F9S2
END
+
CASE WHEN Game.F10S1 = 10 and Game.F10S2 = 10 THEN 20 + Game.F10S3
WHEN Game.F10S1 = 10 and Game.F10S2 < 10 THEN 10 + Game.F10S2 + Game.F10S3
WHEN Game.F10S1 + Game.F10S2 = 10 THEN 10 + Game.F10S3
ELSE Game.F10S1 + Game.F10S2
END
AS GameScore
FROM
(
SELECT
TR.intGameID
,SUM( CASE WHEN TR.intRollIndex = 1 and TR.intRollNumberIndex = 1 THEN TR.intNumberOfPins ELSE 0 END ) F1S1
,SUM( CASE WHEN TR.intRollIndex = 1 and TR.intRollNumberIndex = 2 THEN TR.intNumberOfPins ELSE 0 END ) F1S2
,SUM( CASE WHEN TR.intRollIndex = 2 and TR.intRollNumberIndex = 1 THEN TR.intNumberOfPins ELSE 0 END ) F2S1
,SUM( CASE WHEN TR.intRollIndex = 2 and TR.intRollNumberIndex = 2 THEN TR.intNumberOfPins ELSE 0 END ) F2S2
,SUM( CASE WHEN TR.intRollIndex = 3 and TR.intRollNumberIndex = 1 THEN TR.intNumberOfPins ELSE 0 END ) F3S1
,SUM( CASE WHEN TR.intRollIndex = 3 and TR.intRollNumberIndex = 2 THEN TR.intNumberOfPins ELSE 0 END ) F3S2
,SUM( CASE WHEN TR.intRollIndex = 4 and TR.intRollNumberIndex = 1 THEN TR.intNumberOfPins ELSE 0 END ) F4S1
,SUM( CASE WHEN TR.intRollIndex = 4 and TR.intRollNumberIndex = 2 THEN TR.intNumberOfPins ELSE 0 END ) F4S2
,SUM( CASE WHEN TR.intRollIndex = 5 and TR.intRollNumberIndex = 1 THEN TR.intNumberOfPins ELSE 0 END ) F5S1
,SUM( CASE WHEN TR.intRollIndex = 5 and TR.intRollNumberIndex = 2 THEN TR.intNumberOfPins ELSE 0 END ) F5S2
,SUM( CASE WHEN TR.intRollIndex = 6 and TR.intRollNumberIndex = 1 THEN TR.intNumberOfPins ELSE 0 END ) F6S1
,SUM( CASE WHEN TR.intRollIndex = 6 and TR.intRollNumberIndex = 2 THEN TR.intNumberOfPins ELSE 0 END ) F6S2
,SUM( CASE WHEN TR.intRollIndex = 7 and TR.intRollNumberIndex = 1 THEN TR.intNumberOfPins ELSE 0 END ) F7S1
,SUM( CASE WHEN TR.intRollIndex = 7 and TR.intRollNumberIndex = 2 THEN TR.intNumberOfPins ELSE 0 END ) F7S2
,SUM( CASE WHEN TR.intRollIndex = 8 and TR.intRollNumberIndex = 1 THEN TR.intNumberOfPins ELSE 0 END ) F8S1
,SUM( CASE WHEN TR.intRollIndex = 8 and TR.intRollNumberIndex = 2 THEN TR.intNumberOfPins ELSE 0 END ) F8S2
,SUM( CASE WHEN TR.intRollIndex = 9 and TR.intRollNumberIndex = 1 THEN TR.intNumberOfPins ELSE 0 END ) F9S1
,SUM( CASE WHEN TR.intRollIndex = 9 and TR.intRollNumberIndex = 2 THEN TR.intNumberOfPins ELSE 0 END ) F9S2
,SUM( CASE WHEN TR.intRollIndex = 10 and TR.intRollNumberIndex = 1 THEN TR.intNumberOfPins ELSE 0 END ) F10S1
,SUM( CASE WHEN TR.intRollIndex = 10 and TR.intRollNumberIndex = 2 THEN TR.intNumberOfPins ELSE 0 END ) F10S2
,SUM( CASE WHEN TR.intRollIndex = 10 and TR.intRollNumberIndex = 3 THEN TR.intNumberOfPins ELSE 0 END ) F10S3
FROM
TRolls AS TR
GROUP BY
TR.intGameID ) AS Game )
FROM
TPlayers AS TP
,TGames AS TG
,TRolls AS TR
WHERE
TP.intPlayerID = TG.intPlayerID
AND TG.intGameID = TR.intGameID
AND TP.intPlayerID = 21

Answer 1

It's a bit difficult to debug without the table designs but from what I see in your query, there may be a few issues (again, depending on your table design).
Your inner subquery does not have a Where Statement. Therefore, it
will bring all games in TRolls table, grouped by intGameID; It will
return multiple games; this is probably the issue as the "Game"
subquery is used in a SELECT statement, so it should return only one row;
you may need to add a WHERE clause to your subquery, and
maybe another join, depending on your table structure and their
relationships. If you really need to get the score for each game
(meaning, you don't know the gameID yet) you need to do that in the
FROM statement (not in the select statement as you are) like this
SELECT
TP.intPlayerID
,TP.strLastName + ', ' + TP.strFirstName AS strPlayerName
,TG.*
,TR.intGameID
,Game.Gamescore
FROM
TPlayers AS TP
,TGames AS TG
,TRolls AS TR
, (Select ... ...
) As Game
WHERE ...
From your question I understand in a Game you have multiple Players.
You are filtering just "PlayerID = 21" so you are adding all the
scores from all games for that player - is that what you really want?
Or are you missing another condition to filter a specific game?
You mentioned you are not familiar with subqueries, so here's a quick rule of thumb:
If used in the Select Statement (like yours) a subquery can only
return one row. Always.
If used in the From Statement (like my example) it brings you a
virtual "temp table" with multiple rows, you enclose it in
parenthesis and use an Alias to identify it; then you join it with
other tables in your From Statement using its given Alias.
If used in the Where Statement it should return a boolean value (true
or false), and a common example of that would be verifying whether or
not an information exists somewhere, like this:
WHERE EXISTS (SELECT 'X' from .... Where ....)