How to do conversion of units between two tables in SAP HANA Database - sql

Question

Hi I stumble upon some problem with SAP HANA database please note. I have some toy example problem. I tried to come up with solution, but I cannot figure out.
I have two tables one of Volume table
Row MATERIAL BASE_UOM PERIOD SUMMAND
1 55555 KG 201106 99
2 55555 KG 201204 16
3 55555 KG 201301 71
4 55555 KG 201411 83
5 55555 KG 201509 21
6 55555 PAL 201510 64
7 55555 PAL 201511 69
8 55555 KG 201512 55
9 55555 ZRS 201601 81
10 55555 KG 201602 3
11 55555 KG 201603 74
12 55555 KG 201604 58
13 55555 ZRS 201605 8
14 55555 KG 201606 22
The second table is Conversion Table
Row MATERIAL UNIT BASE_UOM UOMN1D UOMZ1D Conversion Rate
1 55555 KG KG 1 1 1
2 55555 CSE KG 1,000.00 2,016.00 2.016
3 55555 ST KG 1,000.00 56 0.056
4 55555 LAY KG 100 3,024.00 30.24
5 55555 PAL KG 100 54,432.00 544.32
6 55555 ZDK KG 59,778.00 54,432.00 0.910569106
7 55555 ZSE KG 59,778.00 54,432.00 0.910569106
8 55555 ZNO KG 59,778.00 54,432.00 0.910569106
9 55555 ZFI KG 59,778.00 54,432.00 0.910569106
10 55555 ZRV KG 1,000.00 57 0.057
11 55555 ZRS KG 1,000.00 2,052.00 2.052
Please bear in mind that Row column is indicative!
Key between tables is MATERIAL column.
I would like to convert all fields in column SUMMAND (Volume table), when there are not KG in BASE_UOM column Volume table e.g. in row 6 is PAL into KG or row 13 ZRS into KG. If we are in situation that we have KG we do not need to update column SUMMAND. To convert PAL into KG I need to look up at Conversion Table at MATERIAL and UNIT Column (look up PAL field) and get row 5 from Conversion Rate column (UOMZ1D/UOMN1D) 544.32*64 (64 is coming from Volume table row 6 Column SUMMAND) and so on. Finally, each individual MATERIAL has its own conversion rate.
The final output of Volume table should look like this. Row 6,7,9,13 is updated correctly.
Row MATERIAL BASE_UOM PERIOD SUMMAND
1 55555 KG 201106 99
2 55555 KG 201204 16
3 55555 KG 201301 71
4 55555 KG 201411 83
5 55555 KG 201509 21
6 55555 PAL 201510 34836.48
7 55555 PAL 201511 37558.08
8 55555 KG 201512 55
9 55555 ZRS 201601 166.212
10 55555 KG 201602 3
11 55555 KG 201603 74
12 55555 KG 201604 58
13 55555 ZRS 201605 16.416
14 55555 KG 201606 22
How I can check for every possible combination to convert all units into KG between this two tables. Would like to suggest me how to scale it, if I have longer list conversion between UNIT and BASE_UOM from Conversion Table imagine like 90 unique possible combinations. What SQL query I need to build in order to achieve the desired output. Any kind of solution are welcome.

Answer 1

Based on your description, you might want to use an inner join to match up the conversion factors to the material.
Something along the lines of this:
SELECT
v.MATERIAL
, v.BASE_UOM as ORIGINAL_UOM
, v.PERIOD
, c.UNIT as TARGET_OUM
, (c.UOMZ1D/c.UOMN1D) * v.SUMMAND as SUMMAND_TARGET_OUM
FROM
VOLUMES v
INNER JOIN CONVERSION c
ON (v.MATERIAL, v.BASE_UOM)
= (c.MATERIAL, c.UNIT)
This query relies on that there is one and only one matching entry in the conversion table for each possible material/base_uom combination.
If no match can be found, the corresponding record from VOLUMES will be omitted in the output.
It's obviously possible to design this more resilient to missing data (e.g. by fall-back output of unchanged data or transitive lookups), but the given solution is straight forward and easy to understand and debug.
Note, that this does not make use of SAP HANA's built-in unit-of-measure conversion functions. As these are designed to replicate the UOM conversion logic of SAP NetWeaver -based applications, these are probably not what you want in this case.