SQL Query to find missed nunmber from each group

Question

Hi,
I have a set of records called "Level" and its values are A, B, C, D.
From the below list, I want to identify the missed level for each group.
ID          Level          Type
1             A               Floor
1             B                Floor
2             A               Wind           
2             C                Wind
I need result like: [Missed level records]
ID          Level          Type
1               C             NULL     1- doesnt has C and D
1               D             NULL
2               B             NULL      2- doesnt has A and C
2               D             NULL
Pls suggest.
Regards,
-Sugumar Pannerselvam

Answer 1

Hi,
Got output with below code. may helpful for others.
DECLARE @TblLevel TABLE(Level VARCHAR(10))
INSERT INTO @TblLevel(Level) VALUES('A'),('B'),('C'),('D')
DECLARE @TblRecords TABLE(ID INT, Level CHAR(1), Type VARCHAR(10))
INSERT INTO @TblRecords(ID, Level, Type) VALUES(1,'A','Floor'),(1,'B','Floor'),(2,'A','Wind'),(2,'C','Wind')
DECLARE @TblResult TABLE(ID INT, Level CHAR(1), Type VARCHAR(10))
INSERT INTO @TblResult(ID, Level, Type)
SELECT DISTINCT ID, TblLevel.Level, Type
FROM @TblRecords TblRec
CROSS JOIN @TblLevel TblLevel
SELECT TblResult.* FROM @TblResult TblResult
LEFT OUTER JOIN @TblRecords TblRec ON TblResult.ID = TblRec.ID AND TblResult.Level = TblRec.Level
WHERE TblRec.Level IS NULL
ORDER BY 1
Looking for some best way to achieve this. As of now considered this as answer. :-)
Regards,
Sugumar Pannerselvam.