with rn_cte as (
    select *, eow-[Week] wk_diff,
           row_number() over (partition by it, cg,...

In Visual Studio if you hold the Alt key down while using the mouse to highlight text it rectangularly selects areas.  Because the dates are horizontally aligned with just a...

No comment on the date calculations?

declare @start_yr           int=2022;

with months_cte(mo_num) as (
    select * from...

Why store information which is derivable by query?  It sometimes creates race conditions keeping updated.  If you're looking for performance you could try splitting the clustered index away from the...

Here's a query with some date calculations.  The value calculated in CROSS APPLY is the difference in days between the customer's DateofJoin and the order's DateVal.  Based on this difference...

The data contains a duplicate row.  How to handle duplicates?  Also, VID is nullable so are NULLs to be ignored or treated collectively as a VID?

Once they realized the mistake, they attempted to soften the blow by creating DATEDIFF_BIG.  A valiant attempt that works nicely except for the rather obvious and unfortunate fact that...

You could divide the rows using two queries: one above and one below UNION ALL. Above SELECT ID's with [type]='Alias' and below SELECT ID's without any 'Alias'.  You could assign...

One Youtube channel is the CMU Database Group from Carnegie Mellon University.  My brother went to CMU and one of his sons goes there now.  Their earlier series are...

To make the comparison between rows you could use the LAG function.  Then use integer division programYearValue/100 to extract the start year and take the modulo 100 of the lagged...

Why is there no primary key on the extractreports.dbo.partsrecomendationActive table?  You have a clustered index and yet UNIQUE is not specified.   This seems to cause a merge join and it's...

Regarding the time it takes different member have different approaches.  For me it's usually asap without too much nth degree refactoring.  Whatever gets people unstuck.  I'm a developer too so...

Happy it helps!  Thanks for the feedback 😊

It was a medium challenge.  Your follow up post cleared up the lot size issue.  Maybe an hour or so added together.  Estimating...

Thanks for the further explanation.  This query takes a number of passes at the data due to multiple uses of windowing functions. It assumes 'Item' to be a PARTITION BY...

Is this the equation?  The change in monthly quantity is labelled as delta_q.

quantity_on_hand + delta_q + production_proposal - lot_size - minimum_stock = 0

In month 1:

quantity_on_hand=4,000, delta_q=0, lot_size=810, and minimum_stock=4050

4,000+0+production_proposal-810-4050=0

production_proposal=860

In month...