How to get query result with stored procedure (convert item quantity from one table into my unit defined in second table) - sql

Question

I have two MSSQL2008 tables like this:
I have problem on the unit conversion logic.
The result I expect like this :
1589 cigar = 1ball, 5slop, 8box, 2pcs
52 pen = 2box, 12pcs
Basically I'm trying to take number (qty) from one table and to convert (split) him into the units which I defined in other table!
Note : Both table are allowed to add new row and new data (dinamic)
How can I get these results through a SQL stored procedure?

Answer 1

i totally misunderstand the question lest time so previous answer is removed (you can see it in edit but it's not relevant for this question)... However i come up with solution that may solve your problem...
NOTE: one little think about this solution, if you enter the value in second table like this
+--------+-------+
| Item | qty |
+--------+-------+
| 'cigar'| 596 |
+--------+-------+
result for this column will be
598cigar = 0ball, 5slop, 8box, 0pcs
note that there is a ball and pcs is there even if their value is 0, that probably can be fix if you don't want to show that value but I let you to play with it...
So let's back to solution and code. Solution have two stored procedures first one is the main and that one is the one you execute. I call it sp_MainProcedureConvertMe. Here is a code for that procedure:
CREATE PROCEDURE sp_MainProcedureConvertMe
AS
DECLARE #srcTable TABLE(srcId INT IDENTITY(1, 1), srcItem VARCHAR(50), srcQty INT)
DECLARE #xTable TABLE(xId INT IDENTITY(1, 1), xVal1 VARCHAR(1000), xVal2 VARCHAR(1000))
DECLARE #maxId INT
DECLARE #start INT = 1
DECLARE #sItem VARCHAR(50)
DECLARE #sQty INT
DECLARE #val1 VARCHAR(1000)
DECLARE #val2 VARCHAR(1000)
INSERT INTO #srcTable (srcItem, srcQty)
SELECT item, qty
FROM t2
SELECT #maxId = (SELECT MAX(srcId) FROM #srcTable)
WHILE #start <= #maxId
BEGIN
SELECT #sItem = (SELECT srcItem FROM #srcTable WHERE srcId = #start)
SELECT #sQty = (SELECT srcQty FROM #srcTable WHERE srcId = #start)
SELECT #val1 = (CAST(#sQty AS VARCHAR) + #sItem)
EXECUTE sp_ConvertMeIntoUnit #sItem, #sQty, #val2 OUTPUT
INSERT INTO #xTable (xVal1, xVal2)
VALUES (#val1, #val2)
SELECT #start = (#start + 1)
CONTINUE
END
SELECT xVal1 + ' = ' + xVal2 FROM #xTable
GO
This stored procedure have two variables as table #srcTable is basically your second table but instead of using id of your table it's create new srcId which goes from 1 to some number and it's auto_increment it's done because of while loop to avoid any problems when there is some deleted values etc. so we wanna be sure that there wont be any skipped number or something like that.
There is few more variables some of them is used to make while loop work other one is to store data. I think it's not hard to figure out from code what are they used for...
While loop iterate throughout all rows from #srcTable take values processing them and insert them into #xTable which basically hold result.
In while loop we execute second stored procedure which have a task to calculate how many unit of something is there in specific number of item. I call her sp_ConvertMeIntoUnit and here is a code for her:
CREATE PROCEDURE sp_ConvertMeIntoUnit
#inItemName VARCHAR(50),
#inQty INT,
#myResult VARCHAR(5000) OUT
AS
DECLARE #rTable TABLE(rId INT IDENTITY(1, 1), rUnit VARCHAR(50), rQty INT)
DECLARE #yTable TABLE(yId INT IDENTITY(1, 1), yVal INT, yRest INT)
DECLARE #maxId INT
DECLARE #start INT = 1
DECLARE #quentity INT = #inQty
DECLARE #divider INT
DECLARE #quant INT
DECLARE #rest INT
DECLARE #result VARCHAR(5000)
INSERT INTO #rTable(rUnit, rQty)
SELECT unit, qty
FROM t1
WHERE item = #inItemName
ORDER BY qty DESC
SELECT #maxId = (SELECT MAX(rId) FROM #rTable)
WHILE #start <= #maxId
BEGIN
SELECT #divider = (SELECT rQty FROM #rTable WHERE rId = #start)
SELECT #quant = (#quentity / #divider)
SELECT #rest = (#quentity % #divider)
INSERT INTO #yTable(yVal, yRest)
VALUES (#quant, #rest)
SELECT #quentity = #rest
SELECT #start = (#start + 1)
CONTINUE
END
SELECT #result = COALESCE(#result + ', ', '') + CAST(y.yVal AS VARCHAR) + r.rUnit FROM #rTable AS r INNER JOIN #yTable AS y ON r.rId = y.yId
SELECT #myResult = #result
GO
This procedure contain three parametars it's take two parameters from the first one and one is returned as result (OUTPUT). In parameters are Item and Quantity.
There are also two variables as table #rTable we stored values as #rId which is auto increment and always will go from 1 to some number no matter what is there Id's in the first table. Other two values are inserted there from the first table based on #inItemName parameter which is sanded from first procedure... From the your first table we use unit and quantity and stored them with rId into table #rTable ordered by Qty from biggest number to lowest. This is a part of code for that
INSERT INTO #rTable(rUnit, rQty)
SELECT unit, qty
FROM t1
WHERE item = #inItemName
ORDER BY qty DESC
Then we go into while loop where we do some maths. Basically we store into variable #divider values from #rTable. In the first iteration we take the biggest value calculate how many times it's contain into the number (second parameter we pass from first procedure is qty from the yours second table) and store it into #quant than we also calculate modulo and store it into variable #rest. This line
SELECT #rest = (#quentity % #divider)
After that we insert our values into #yTable. Before we and with iteration in while loop we assign #quentity variable value of #rest value because we need to work just with the remainder not with whole quantity any more. In second iteration we take next (the second greatest number in our #rTable) number and procedure repeat itself...
When while loop finish we create a string. This line here:
SELECT #result = COALESCE(#result + ', ', '') + CAST(y.yVal AS VARCHAR) + r.rUnit FROM #rTable AS r INNER JOIN #yTable AS y ON r.rId = y.yId
This is the line you want to change if you want to exclude result with 0 (i talk about them at the beginning of answer)...
And at the end we store result into output variable #myResult...
Result of this stored procedure will return string like this:
+--------------------------+
| 1ball, 5slop, 8box, 2pcs |
+--------------------------+
Hope I didn't miss anything important. Basically only think you should change here is the name of the table and their columns (if they are different) in first stored procedure instead t2 here
INSERT INTO...
SELECT item, qty
FROM t2
And in second one instead of t1 (and column if needed) here..
INSERT INTO...
SELECT unit, qty
FROM t1
WHERE item = #inItemName
ORDER BY qty DESC
Hope i help a little or give you an idea how this can be solved...
GL!

Answer 2

You seem to want string aggregation – something that does not have a simple instruction in Transact-SQL and is usually implemented using a correlated FOR XML subquery.
You have not provided names for your tables. For the purpose of the following example, the first table is called ItemDetails and the second one, Items:
SELECT
i.item,
i.qty,
details = (
SELECT
', ' + CAST(d.qty AS varchar(10)) + d.unit
FROM
dbo.ItemDetails AS d
WHERE
d.item = i.item
FOR XML
PATH (''), TYPE
).value('substring(./text()[1], 3)', 'nvarchar(max)')
FROM
dbo.Items AS i
;
For the input provided in the question, the above query would return the following output:
item qty details
----- ----------- ------------------------------
cigar 1598 1pcs, 1000ball, 12box, 100slop
pen 52 1pcs, 20box
You can further arrange the data into strings as per your requirement. I would recommend you do it in the calling application and use SQL only as your data source. However, if you must, you can do the concatenation in SQL as well.
Note that the above query assumes that the same unit does not appear more than once per item in ItemDetails. If it does and you want to aggregate qty values per unit before producing the detail line, you will need to change the query a little:
SELECT
i.item,
i.qty,
details = (
SELECT
', ' + CAST(SUM(d.qty) AS varchar(10)) + d.unit
FROM
dbo.ItemDetails AS d
WHERE
d.item = i.item
GROUP BY
d.unit
FOR XML
PATH (''), TYPE
).value('substring(./text()[1], 3)', 'nvarchar(max)')
FROM
dbo.Items AS i
;