Re: Select Maths - Mailing list pgsql-sql

From Aaron Bono
Subject Re: Select Maths
Date
Msg-id bf05e51c0607102041nc10f58fmeb1869b3d38c677e@mail.gmail.com
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In response to Re: Select Maths  ("Phillip Smith" <phillips@weatherbeeta.com.au>)
Responses Re: Select Maths  ("Phillip Smith" <phillips@weatherbeeta.com.au>)
List pgsql-sql
On 7/10/06, Phillip Smith <phillips@weatherbeeta.com.au> wrote:

Example:

Funcation pqty(stock.code) calculates a value of 0 for a particular product. This fails the last CASE that makes sure the pqty() value is greater than our Usage Rate * Review Cycle – in this case is 3. But that is less than our Minimum Order Qty (First CASE) and not a multiple of our Box Qty (Second CASE)

Another example could be that pqty() calculates less than the Minimum Order Qty (fails first CASE) so we raise it to the Minimum Order Qty, but that new value could fail either or both of the second CASE's.

Minimum Order Qty = stock.purchase_unit
Box Qty = stock.box_qty

I guess a better way to word it is that because pqty() returns a calculated value each time and I can't take that value and assign it to a variable, then use that variable. If I was writing VB or similar I'd want something like:

intPurchaseQty = pqty(stock.code)

CASE  WHEN intPurchaseQty < stock.purchase_unit THEN intPurchaseQty = stock.purchase_unit

WHEN MOD(intPurchaseQty, stock.box_qty) > 0 THEN intPurchaseQty = stock.box_qty * ROUND(CAST(intPurchaseQty AS DOUBLE PRECISION) / stock.box_qty)

WHEN intPurchaseQty < (urate(stock.code) * creditors.review_cycle) THEN intPurchaseQty = urate(stock.code) * creditors.review_cycle

END

COLUMN = intPurchaseQty AS "pqty",

I hope that makes it a lighter shade of mud!!


Why wouldn't you be able to do this in a function?  Pass in stock.code, stock.purchase_unit, stock.box_qty and creditors.review_cycle .  You can then use variables in the function, right?

-Aaron

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