SQL To delete number of items is less than required item number - sql

Question

I have two tables - StepModels (support plan) and FeedbackStepModels (feedback), StepModels keeps how many steps each support plan requires.
SELECT [SupportPlanID],COUNT(*)AS Steps
FROM [StepModels]
GROUP BY SupportPlanID
SupportPlanID (Steps)
-------------------------------
1 4
2 9
3 3
4 10
FeedbackStepModels keeps how many steps employee entered the system
SELECT [FeedbackID],SupportPlanID,Count(*)AS StepsNumber
FROM [FeedbackStepModels]
GROUP BY FeedbackID,SupportPlanID
FeedbackID SupportPlanID
---------------------------------------------
1 1 3 --> this suppose to be 4
2 2 9 --> Correct
3 3 0 --> this suppose to be 3
4 4 10 --> Correct
If submitted Feedback steps total is less then required total amount I want to delete this wrong entry from the database. Basically i need to delete FeedbackID 1 and 3.
I can load the data into List and compare and delete it, but want to know if we can we do this in SQL rather than C# code.

Answer 1

You can use the query below to remove your unwanted data by SQL Script
DELETE f
FROM FeedbackStepModels f
INNER JOIN (
SELECT [FeedbackID],SupportPlanID, Count(*) AS StepsNumber
FROM [FeedbackStepModels]
GROUP BY FeedbackID,SupportPlanID
) f_derived on f_derived_FeedbackID=f.FeedBackID and f_derived.SupportPlanID = f.SupportPlanID
INNER JOIN (
SELECT [SupportPlanID],COUNT(*)AS Steps
FROM [StepModels]
GROUP BY SupportPlanID
) s_derived on s_derived.SupportPlanID = f.SupportPlanID
WHERE f_derived.StepsNumber < s_derived.Steps

Answer 2

I think you want something like this.
DELETE FROM [FeedbackStepModels]
WHERE FeedbackID IN
(
SELECT a.FeedbackID
FROM
(
SELECT [FeedbackID],
SupportPlanID,
COUNT(*) AS StepsNumber
FROM [FeedbackStepModels]
GROUP BY FeedbackID,
SupportPlanID
) AS a
INNER JOIN
(
SELECT [SupportPlanID],
COUNT(*) AS Steps
FROM [StepModels]
GROUP BY SupportPlanID
) AS b ON a.SupportPlanID = b.[SupportPlanID]
WHERE a.StepsNumber < b.Steps
);