Cumulative vs. Tiered Calculation in SQL Query or Inline Table Value Function with Conditional Logic? - sql

Question

I'm working with two tables of data, but different methodologies to derive two distinct desired outputs below.
The first is a cumulative tier calculation and the second is a just a tiered lookup based on a range. I need to be able to return this calculation for a row item transaction based on some JOINS using foreign keys to other dimension tables, namely Accounts and Regions and Tier Type. For example, a single account could have a calculation be either cumulative or tiered based on the region's and/or account's ID.
Link to DB Fiddle
Type ID
Name
1
Cumulative
2
Tiered
Tiered table:
Account ID
Type ID
Region ID
TierNo
Min
Max
Total A
Total B
101
1
2
1
0
10000
.90
.10
101
1
2
2
10001
30000
.60
.40
101
1
2
3
30001
100000
.40
.60
101
1
2
4
100001
500000
.40
.60
101
1
2
5
500001
999999999999
.20
.80
102
1
3
1
0
7800
.80
.20
102
1
3
2
7801
12800
.70
.30
102
1
3
3
12801
34000
.60
.40
102
1
3
4
34001
50000
.50
.50
102
1
3
5
5000 1
999999999999
.50
.50
103
2
1
1
0
10000
.90
.10
103
2
1
2
10001
30000
.60
.40
103
2
1
3
30001
100000
.40
.60
103
2
1
4
100001
500000
.40
.60
103
2
1
5
500001
999999999999
.20
.80
Current table sample:
Trans ID
Account ID
Type ID
Region ID
GrossAmt
Total A %
Total A $
Net Amt
100001
101
1
2
42650
100002
102
1
3
42650
100003
103
2
1
42650
Desired output:
Trans ID
Account ID
Type ID
Region ID
GrossAmt
Total A %
Total A $
Net Amt
100001
101
1
2
42650
0.611
26059.99
16589.99
100002
102
1
3
42650
0.628
26784.98
15864.99
100003
103
2
1
42650
0.40
17060.00
25590.00
I've been able to make some edits to a previous post to get the accounts, but can't seem to figure out the logic for the tiered lookup value in TransID 100003.
Ideally, I'd prefer to create this logic in a table value function (or two) and then incorporate it into a View that I'll use for reporting in a web form using C#.
SELECT
c.*,
[Total A %] = t.Total / c.GrossAmt,
[Total A $] = t.Total,
[Net Amt] = c.GrossAmt - t.Total
FROM #temp c
INNER JOIN Accounts a ON a.[Account ID] = c.[Account ID]
CROSS APPLY (
SELECT
Total = SUM((v.ActualMax - t.[Min]) * t.[Total A %])
FROM [dbo].[Tiered Table] t
CROSS APPLY (VALUES(
CASE WHEN c.GrossAmt < t.[Max] THEN c.GrossAmt ELSE t.[Max] END
)) v(ActualMax)
WHERE c.GrossAmt > t.[Min] AND t.[Account ID] = c.[Account ID]
) t;
Any ideas or guidance would be extremely helpful and appreciated.

Answer 1

It seems to be a simple matter of AND OR logic. You need to exclude rows which are TypeID = 2 and also have their maximum below the level of GrossAmt.
Then you just conditionally aggregate either the total amount (for tiered rows only, there will be only one row) or just the amount for that tier (for cumulative tiers).
SELECT
c.*,
[Total A %] = t.Total / c.GrossAmt,
[Total A $] = t.Total,
[Net Amt] = c.GrossAmt - t.Total
FROM CurrentData c
INNER JOIN Accounts a ON a.[AccountID] = c.[AccountID]
CROSS APPLY (
SELECT
Total = SUM(CASE WHEN t.TypeID = 2 THEN v.GrossAmt ELSE (v.ActualMax - t.[Min]) END * t.[Total A])
FROM [dbo].[Tiers] t
CROSS APPLY (VALUES(
CASE WHEN c.GrossAmt < t.[Max] THEN c.GrossAmt ELSE t.[Max] END,
c.GrossAmt
)) v(ActualMax, GrossAmt)
WHERE t.[AccountID] = c.[AccountID]
AND t.TypeID = c.TypeID
AND t.RegionID = c.RegionID
AND c.GrossAmt > t.[Min]
AND (t.TypeID = 1 OR c.GrossAmt <= t.Max)
) t;
db<>fiddle
The second CROSS APPLY is only necessary because of aggregating outer values. You don't need this if you place it in a function, as shown in your previous question.
Note that you should use half-open intervals here. In other words, either Min or Max should be exclusive. Otherwise there may be values that can "fall through the cracks".