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The ‘FIFO Stock Inventory’ SQL Problem

Phil Factor SQL Speed Phreak Competition: No 2

alt text

This competition is now over, but the winner, Dave, got an Amazon Voucher for $60, and the privilege of being able to display the 'Phil Factor SQL Speed Phreak' award on their own site

It was quite a struggle with some close competition from many of those who participated in this competition. However, Dave came up with a clever solution that produced an FIFO calculation from a million rows in a just a few seconds. The third Phil Factor Speed Phreak competition will soon be held on here. Watch out!


(here is the original preamble.)

This competition is to calculate current items in stock and current stock value in FIFO order.
I'll tell you the business rules for the algorithm and provide a sample cursor-based routine that generates the correct result, but slowly (about 40 minutes).

I have seen many different algorithms to do this and most of them involve a cursor. Can it be done more quickly without, or even with, a cursor? In other words, what is the fastest way in SQL Server (any version) to provide this stock inventory report?
It is a reasonable request. We have a stock transaction list (1,000,001 records, 17.6MB zipped) with 15,002 unique articles and we need to do a stock inventory report that gives the current breakdown of the ArticleID, the number of items in stock and the current stock value according to FIFO rules. The list should be in ArticleID order. The sample stock transaction list will include two running totals so you can check the results of your routine. They are NOT part of the competition, and you are not allowed to use them in your calculation.

Beware that the sample file includes the two extra columns; CurrentItems (INT) and CurrentValue (MONEY) !
If you want a smaller subset to test on, import all records and remove all articles but two or three. These are the samples for which all suggestions will be measured with.

The table is in this form (simplified from the way we'd do it in a real system of course).
In this made-up but realistic problem, you have an existing table and database design which you can’t do anything about. (we can all relate to that!) You have an existing cursor-based solution that is taking several minutes to run. (Yes, we all relate to that). The database is performing badly, and you need to take effective steps to remedy this. The only thing you can do is to come up with a better-performing routine. Redesigning the database isn’t an option very often, in the real world, because this requires team sign-in. This is a competition based on the real, sometimes imperfect, world: not an exposition of database design. The point is that we are faced with designs like this and we have to heal them. The competition is all about making stuff go faster.

CREATE TABLE    dbo.Stock
                (
                    StockID INT IDENTITY(1, 1) NOT NULL,
                    ArticleID SMALLINT NOT NULL,
                    TranDate DATETIME NOT NULL,
                    TranCode VARCHAR(3) NOT NULL,
                    Items INT NOT NULL,
                    Price MONEY NULL,
                    CONSTRAINT [PK_Stock] PRIMARY KEY CLUSTERED 
                    (
                        StockID ASC
                    )
                )  

CREATE NONCLUSTERED INDEX IX_Input ON dbo.Stock (TranCode, ArticleID)
--INCLUDE (TranDate, Items, Price) -- Remove comment for SQL Server 2005 and later
--WHERE TranCode IN ('IN', 'RET')   -- Remove comment for SQL Server 2008

CREATE NONCLUSTERED INDEX IX_Output ON dbo.Stock (TranCode, ArticleID)
-- INCLUDE (TranDate, Items) -- Remove comment for SQL Server 2005 and later
--WHERE TranCode = 'OUT'  -- Remove comment for SQL Server 2008

You are welcome to change the two nonclustered indexes to suit your solution. You can download the complete sample data here. I have an idea of my own of the way to do this but I don’t know if it is the fastest.

Explanation of FIFO rules (example, abbreviated)

StockID ArticleID TranDate TranCode Items  Price CurrentItems CurrentValue
   4567     10000 10:45:07 IN         738 245.94          738   181,503.72
  21628     10000 12:05:25 OUT        600                 138    33,939.72
  22571     10000 14:39:27 IN          62 199.95          200    46,336.62
  30263     10000 16:14:13 OUT        165                  35     6,998.25
  42090     10000 18:18:58 RET          5                  40     7,998.00
  58143     10000 20:18:54 IN         500 135.91          540    75,953.00

a) First IN add 738 items (each $245.94) to the stock, for a total of $181,503.72
b) Then we take out 600 items (each 245.94) from the stock, leaving a total of $33,939.72
c) Then we insert 62 items (each 199.95) to the stock, for a total of $46,336.62
d) Then we take out 165 items (138 each 245.94 and 27 each 199.95), leaving a total of $6,998.25
e) Then we return 5 items. We can’t track at which price we took them out; so all returns are priced at the price of the latest ones inserted before the return. Even if there should be items left for the price of 245.94, the returned items are valued for 199.95. After the return, the current stock value is $7,998.00
f) The final insert adds $67,995.00 to the stock value, for a total of $75,953.00

As mentioned before, the CurrentItems and CurrentValue columns in the sample data are only included for you to validate your routines.

Here are some guidelines for your entries:

1) Include a header in your suggestion. Make sure your name and date is present.
2) Include an edition number. First edition is 1. If you later improve your current suggestion post it again as version 2. Example: “Peso 1” and if improved, “Peso 1b”, “Peso 1c” etc.
3) If you are trying a new algorithm, change the edition to “Peso 2”. If you improve this algorithm, change the version to “Peso 2b”, “Peso 2c” etc. This will save Phil hours of work in the test harness!
4) If you create a temp table, make sure you delete it in the script.
5) Keep the order of columns in output as ArticleID, CurrentItems, CurrentValue

I will allow you to use an existing tally number table (make sure it starts with 0). You can use any kind of object for this competition, except SQLCLR. If you are using a fixed tally number table, it has to be named dbo.TallyNumbers and the column named Number.
The time taken for their creation will not be included in the timings. The time measured is the “Main” script/procedure. If you want to call sub-procedures, go ahead.

The winner will be amongst the tied fastest entrants (generally there is a group of these) and it will be the one with the highest number of votes. We'll announce the winner in three week's time on 16th November.

For a starter, here is a common cursor based solution that you will find in production in many places.

CREATE TABLE    #Work
                (
                    RowID INT IDENTITY(1, 1) PRIMARY KEY CLUSTERED,
                    Price MONEY
                )  

DECLARE @ArticleID INT = 1,
        @PrevID INT = 0,
        @TranCode VARCHAR(3),
        @Items INT,
        @Price MONEY,
        @Loop INT = 0,
        @StockID INT,
        @LatestPrice MONEY,
        @Total INT = (SELECT COUNT(*) FROM dbo.Stock)

DECLARE curYak CURSOR FORWARD_ONLY FOR
                SELECT      ArticleID,
                            TranCode,
                            Items,
                            Price,
                            StockID
                FROM        dbo.Stock
                ORDER BY    ArticleID,
                            TranDate

OPEN    curYak

FETCH   NEXT
FROM    curYak
INTO    @ArticleID,
        @TranCode,
        @Items,
        @Price,
        @StockID

WHILE @@FETCH_STATUS = 0
    BEGIN
        IF @ArticleID > @PrevID
            BEGIN
                TRUNCATE TABLE  #Work

                SET @LatestPrice = NULL
            END

        IF @TranCode = 'IN'
            BEGIN
                INSERT  #Work
                        (
                            Price
                        )
                SELECT  @Price
                FROM    dbo.TallyNumbers
                WHERE   Number < @Items

                SET     @LatestPrice = @Price
            END

        IF @TranCode = 'RET'
            INSERT  #Work
                    (
                        Price
                    )
            SELECT  @LatestPrice
            FROM    dbo.TallyNumbers
            WHERE   Number < @Items

        IF @TranCode = 'OUT'
            DELETE  w
            FROM    (
                        SELECT      TOP(@Items)
                                    RowID
                        FROM        #Work
                        ORDER BY    RowID
                    ) AS w

        UPDATE      s
        SET         s.CurrentItems = w.CurrentItems,
                    s.CurrentValue = COALESCE(w.CurrentValue, 0)
        FROM        dbo.Stock AS s
        INNER JOIN  (
                        SELECT  COUNT(*) AS CurrentItems,
                                SUM(Price) AS CurrentValue
                        FROM    #Work
                    ) AS w ON s.StockID = @StockID

        SELECT  @PrevID = @ArticleID,
                @Loop += 1

        IF @Loop % 1000 = 0
            RAISERROR('Now updating record %d of %d.', 10, 1, @Loop, @Total) WITH NOWAIT

        FETCH   NEXT
        FROM    curYak
        INTO    @ArticleID,
                @TranCode,
                @Items,
                @Price,
                @StockID
    END

DROP TABLE  #Work

CLOSE       curYak
DEALLOCATE  curYak

The above is already done. Here is the code to produce the final resultset.

SELECT      ArticleID,
            CurrentItems,
            CurrentValue
FROM        (
                SELECT  ArticleID,
                        CurrentItems,
                        CurrentValue,
                        ROW_NUMBER() OVER (PARTITION BY ArticleID ORDER BY TranDate DESC) AS recID
                FROM    dbo.Stock
            ) AS d
WHERE       recID = 1
ORDER BY    ArticleID

Good luck to you all!

Peter Larsson

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asked Oct 23, 2009 at 03:56 PM in Default

Peso gravatar image

Peso
1.6k 5 6 8

Was there any particular reason you disallowed CLR functionality?

On an initial look, this would be the ideal scenario in which to use a CLR type...
Oct 23, 2009 at 04:34 PM Peso
Two things had us made this decision: 1) We have tried CLR before and there was no performance gain. 2) To test and verify, poster need to disclode the source code for the suggestion. But if you have a CLR routine that runs on 15 seconds or less, I think Phil will be interested in testing it.
Oct 23, 2009 at 05:08 PM Peso
Questions: 1) Is the Stock Transaction List referred to the one that will be used for Final Evaluation? If not, can you describe the differences? 2) What is the configuration that entries will be (finally) evaluated on?
Oct 23, 2009 at 05:09 PM RBarryYoung
Yes, the downloadable file is the data against all suggestions will be measured. Phil will drop or rename the two last columns so that no suggestion can use them. I guess Phil will be using same test harness as last time with 'Subscription List' competition.
Oct 23, 2009 at 05:16 PM Peso
Those filtered indexes will only work on SQL Server 2008, right?
Oct 23, 2009 at 05:46 PM RBarryYoung
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28 answers: sort newest

Dave Ballantyne - Phil Factor Challenge Entry 3.d

Peso had adding some index hints and shuffled a calculation to my initial 3.a. So this is 3.a(+) with comments

with 3.d doing the TotalStock sum in one operation shaves some more time off

“A problem well stated is a problem half solved” - Charles F. Kettering

Let us think about what has been asked within the challenge.

We have a warehouse which starts empty , the data contains the stock movements in (including returns) and out. The stock movements ALWAYS happen in a first in first out basis. With this we know that if the present stock level (sum(in's) - sum(out's) is 50 that will be the last 50 that have entered the warehouse. The key to this query is to efficiently find the cost of those 50 items.

 CREATE NONCLUSTERED INDEX [IX_Dave_General] ON [dbo].[Stock]  (  [ArticleID] ASC,  [TranDate] DESC,  [TranCode] ASC  )  INCLUDE ( [Items],  [Price]) WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, SORT_IN_TEMPDB = OFF, IGNORE_DUP_KEY = OFF, DROP_EXISTING = OFF, ONLINE = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]
GO
CREATE NONCLUSTERED INDEX [IX_Dave_Items] ON [dbo].[Stock]
(
        [ArticleID] ASC,
        [TranDate] ASC
)
INCLUDE ( [Items])
WHERE ([TranCode] IN ('IN', 'RET'))
WITH (PAD_INDEX  = OFF, STATISTICS_NORECOMPUTE  = OFF, SORT_IN_TEMPDB = OFF, IGNORE_DUP_KEY = OFF, DROP_EXISTING = OFF, ONLINE = OFF, ALLOW_ROW_LOCKS  = ON, ALLOW_PAGE_LOCKS  = ON) ON [PRIMARY]

GO

CREATE NONCLUSTERED INDEX [IX_Dave_Price] ON [dbo].[Stock]
(
        [ArticleID] ASC,
        [TranDate] ASC
)
INCLUDE ( [Price])
WHERE ([TranCode]='IN')
WITH (PAD_INDEX  = OFF, STATISTICS_NORECOMPUTE  = OFF, SORT_IN_TEMPDB = OFF, IGNORE_DUP_KEY = OFF, DROP_EXISTING = OFF, ONLINE = OFF, ALLOW_ROW_LOCKS  = ON, ALLOW_PAGE_LOCKS  = ON, FILLFACTOR = 100) ON [PRIMARY]

GO

/* Sum up the ins and outs to calculate the remaining stock level */ ;WITH cteStockSum AS (

  SELECT  ArticleID,
        SUM(CASE  WHEN TranCode = 'OUT' THEN 0-Items
                  ELSE Items END) AS TotalStock
        FROM  dbo.Stock
  GROUP BY  ArticleID

), /* Perform a rolling balance ( in reverse order ) through the stock movements in / cteReverseInSum AS ( SELECT s.ArticleID, s.TranDate, ( SELECT SUM(i.Items) FROM dbo.Stock AS i WITH (INDEX (IX_Dave_Items)) WHERE i.ArticleID = s.ArticleID AND i.TranCode IN ('IN', 'RET') AND i.TranDate >= s.TranDate / SELECT SUM(i.Items) FROM dbo.vwStockIn as i with (index (idxStockInArtTrans)) WHERE i.ArticleID = s.ArticleID AND i.TranDate >= s.TranDate*/

       ) AS RollingStock,
       s.Items AS ThisStock
 FROM  dbo.Stock AS s
WHERE  s.TranCode IN ('IN', 'RET')

), /* Using the rolling balance above find the first stock movement in that meets (or exceeds) our required stock level / / and calculate how much stock is required from the earliest stock in */ cteWithLastTranDate AS ( SELECT w.ArticleID, w.TotalStock, LastPartialStock.TranDate, LastPartialStock.StockToUse, LastPartialStock.RunningTotal, w.TotalStock - LastPartialStock.RunningTotal + LastPartialStock.StockToUse AS UseThisStock

  FROM cteStockSum AS w
       CROSS APPLY  ( SELECT TOP(1)  
                             z.TranDate,
                             z.ThisStock AS StockToUse,
                             z.RollingStock AS RunningTotal
                        FROM cteReverseInSum AS z
                       WHERE z.ArticleID = w.ArticleID
                         AND z.RollingStock &gt;= w.TotalStock
                    ORDER BY z.TranDate DESC ) AS LastPartialStock
) /* Sum up the cost of 100% of the stock movements in after the returned stockid and for that stockid we need 'UseThisStock' items' / SELECT y.ArticleID, y.TotalStock as CurrentItems , SUM(CASE WHEN e.TranDate = y.TranDate THEN y.UseThisStock ELSE e.Items END * Price.Price) AS CurrentValue FROM cteWithLastTranDate AS y INNER JOIN dbo.Stock AS e WITH (INDEX (IX_Dave_Items)) ON e.ArticleID = y.ArticleID AND e.TranDate >= y.TranDate AND e.TranCode IN ('IN', 'RET') CROSS APPLY ( / Find the Price of the item in */ SELECT TOP(1)
p.Price FROM dbo.Stock AS p WITH (INDEX (IX_Dave_Price)) WHERE p.ArticleID = e.ArticleID AND p.TranDate <= e.TranDate AND p.TranCode = 'IN' ORDER BY p.TranDate DESC ) AS Price GROUP BY y.ArticleID, y.TotalStock ORDER BY y.ArticleID go
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answered Nov 05, 2009 at 06:03 AM

dave ballantyne gravatar image

dave ballantyne
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Great job Dave! I was able to get mine down to 2900ms with a couple index hints but still not fast enough.

Cheers Scot

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answered Nov 15, 2009 at 05:39 PM

ScotHauder_ gravatar image

ScotHauder_
1

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Here's an alternative solution, based on a tally table triangular join. I would have expected it to be quicker than my previous entry, but it's not. I'm posting just for the fun of it and for those interested in taking a look at a different approach. The cost is 92% in the aggregate after the triangular join and I wasn't able to get rid of it. Maybe some of you can squeeze something more out of this query.

-- Gianluca Sartori 3a -- Tally triangular join

SELECT ArticleId, CurrentItems = SUM(CASE Number WHEN 1 THEN Items - ISNULL(OutItems,0) ELSE 0 END), CurrentValue = SUM(CASE RN4 WHEN 1 THEN Items - ISNULL(OutItems,0) ELSE LastItem END * LastPrice) FROM ( SELECT *, RN4 = ROW_NUMBER() OVER (PARTITION BY ArticleId ORDER BY Number DESC) FROM ( SELECT ArticleId, Number, SUM(Items) AS Items, SUM(CASE WHEN RN3 = Number THEN Items ELSE 0 END) AS LastItem, SUM(CASE WHEN RN3 = Number THEN Price ELSE 0 END) AS LastPrice FROM ( SELECT ArticleId, RN3 = ROW_NUMBER() OVER (PARTITION BY ArticleId ORDER BY MIN(StockId) DESC), SUM(Items) Items, Price = SUM(Price) FROM ( SELECT *, RN = ROW_NUMBER() OVER (PARTITION BY ArticleId ORDER BY StockId) FROM ( SELECT StockId, ArticleId, TranCode, Items, Price, RN2 = ROW_NUMBER() OVER (PARTITION BY ArticleId ORDER BY StockId) FROM Stock WHERE TranCode = 'IN' UNION ALL SELECT StockId, ArticleId, TranCode, Items, Price, RN2 = ROW_NUMBER() OVER (PARTITION BY ArticleId ORDER BY StockId) FROM Stock WHERE TranCode = 'RET' ) AS S ) AS A GROUP BY ArticleId, CASE TranCode WHEN 'IN' THEN RN2 ELSE RN - RN2 END ) AS B INNER JOIN TallyNumbers AS T ON RN3 >= T.Number GROUP BY ArticleId, Number ) AS C CROSS APPLY ( SELECT SUM(Items) AS OutItems FROM Stock WHERE ArticleId = C.ArticleId AND TranCode = 'OUT' ) AS D WHERE Items >= ISNULL(OutItems,0) ) AS E GROUP BY ArticleId ORDER BY ArticleId
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answered Nov 13, 2009 at 02:31 PM

Gianluca Sartori gravatar image

Gianluca Sartori
228 1 4

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Ok, well I would post a pure set based solution, except that the site is refusing to let me post the whole thing!! Lame.

Anyway, the SQL is just

EXEC [dbo].[FIFOStock]

It runs in about 6.3 seconds on my box.

There are two source files, one for the support class (mostly the same guts as the CLR type version, except for the fact that IBinarySerialize support is removed, and it is now class, rather than struct based).

FIFOStock Procedure:

using System;
using System.Data;
using System.Data.SqlClient;
using System.Data.SqlTypes;
using Microsoft.SqlServer.Server;

public partial class StoredProcedures
{
    [Microsoft.SqlServer.Server.SqlProcedure]
    public static void FIFOStock()
    {
        using (SqlConnection connection = new SqlConnection("context connection=true"))
        {
            connection.Open();
            using (SqlCommand command = new SqlCommand("SELECT [ArticleID], CASE [TranCode] WHEN 'IN' THEN 1 WHEN 'OUT' THEN 2 ELSE 3 END, [Items], [Price] FROM [dbo].[Stock] ORDER BY [ArticleID], [TranDate]", connection))
            {
                short lastArticleID = -1;
                StockStack ss = new StockStack();

                // Create a record object that represents an individual row, including it's metadata.
                SqlDataRecord record =
                    new SqlDataRecord(new SqlMetaData[] {
                    new SqlMetaData("ArticleID", SqlDbType.Int),
                    new SqlMetaData("CurrentItems", SqlDbType.Int),
                    new SqlMetaData("CurrentValue", SqlDbType.Money),
                });

                SqlContext.Pipe.SendResultsStart(record);

                using (SqlDataReader reader = command.ExecuteReader())
                {
                    while (reader.Read())
                    {
                        short articleID = reader.GetInt16(0);
                        if (articleID != lastArticleID)
                        {
                            if (lastArticleID != -1)
                            {
                                // Populate the record.
                                record.SetInt32(0, lastArticleID);
                                record.SetInt32(1, ss.TotalCount);
                                record.SetSqlMoney(2, ss.TotalPrice);

                                SqlContext.Pipe.SendResultsRow(record);
                            }
                            ss = new StockStack();
                            lastArticleID = articleID;
                        }
                        int opCode = reader.GetInt32(1);
                        switch (opCode)
                        {
                            case 1:
                            {
                                ss.AddStock(reader.GetSqlMoney(3), reader.GetInt32(2));
                            } break;
                            case 2:
                            {
                                ss.RemoveStock(reader.GetInt32(2));
                            } break;
                            case 3:
                            {
                                ss.ReturnStock(reader.GetInt32(2));
                            } break;
                        }
                    }

                    // populate and emit the final record
                    record.SetInt32(0, lastArticleID);
                    record.SetInt32(1, ss.TotalCount);
                    record.SetSqlMoney(2, ss.TotalPrice);
                    SqlContext.Pipe.SendResultsRow(record);
                }
                SqlContext.Pipe.SendResultsEnd();
            }
        }
    }
}

StockStack class:

using System; using System.Data; using System.Data.SqlClient; using System.Data.SqlTypes; using Microsoft.SqlServer.Server; using System.Collections.Generic; using System.Text;

internal class StockStack { public override string ToString() { StringBuilder sb = new StringBuilder(1024); foreach (StockStackItem ssi in _stackItems) { sb.Append(ssi.Value); sb.Append(" x "); sb.AppendLine(ssi.Count.ToString()); } sb.Append("---"); sb.Append(TotalPrice.ToString()); sb.Append(" - "); sb.Append(TotalCount.ToString()); return sb.ToString(); }

public void ReturnStock(int Count)
{
    _stackItems[_stackItems.Count - 1].ReturnStock(Count);
}

public void AddStock(SqlMoney Price, int Count)
{
    _stackItems.Add(new StockStackItem((Decimal)Price, Count));
}

public void RemoveStock(int Count)
{
    int itemsLeft = 0;
    bool itemEmpty = false;
    while (true)
    {
        _stackItems[0].RemoveStock(Count, out itemsLeft, out itemEmpty);

        if (itemEmpty)
        {
            _stackItems.RemoveAt(0);
        }
        if (itemsLeft == 0)
        {
            return;
        }
        Count = itemsLeft;
    }
}

public int TotalCount
{
    get
    {
        int totalCount = 0;
        foreach (StockStackItem ssi in _stackItems)
        {
            totalCount += ssi.Count;
        }
        return totalCount;
    }
}


public SqlMoney TotalPrice
{
    get
    {
        Decimal totalValue = 0;
        foreach (StockStackItem ssi in _stackItems)
        {
            totalValue += ssi.TotalValue;
        }
        return totalValue;
    }
}

public static StockStack GetInitialisedStack(SqlMoney Price, int Count)
{
    StockStack ss = new StockStack();
    ss._stackItems.Add(new StockStackItem((Decimal)Price, Count));
    return ss;
}

public static StockStack Empty
{
    get
    {
        return new StockStack();
    }
}

public static StockStack Parse(SqlString s)
{
    // no implementation of from-string for this type
    return StockStack.Empty;
}

// List of items in the stock stack
private List&lt;StockStackItem&gt; _stackItems = new List&lt;StockStackItem&gt;(4);

private class StockStackItem
{
    Decimal _stackItemValue;
    int _stackItemCount;

    public void ReturnStock(int Count)
    {
        _stackItemCount += Count;
    }

    public int Count
    {
        get
        {
            return _stackItemCount;
        }
    }

    public Decimal Value
    {
        get
        {
            return _stackItemValue;
        }
    }

    public Decimal TotalValue
    {
        get
        {
            return _stackItemValue * _stackItemCount;
        }
    }

    public void RemoveStock(int Count, out int RemainingItems, out bool IsEmpty)
    {
        if (_stackItemCount &gt; Count)
        {
            RemainingItems = 0;
            IsEmpty = false;
            _stackItemCount -= Count;
        }
        else 
        {
            RemainingItems = Count - _stackItemCount;
            IsEmpty = true;
            _stackItemCount = 0;
        }
    }

    public StockStackItem(Decimal StackItemValue, int StackItemCount)
    {
        _stackItemValue = StackItemValue;
        _stackItemCount = StackItemCount;
    }
}
}
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answered Nov 12, 2009 at 11:00 AM

Matt Whitfield gravatar image

Matt Whitfield ♦♦
29.4k 61 65 87

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Here is my cursor solution as counterweight to all set-based solutions :-)

-- Peso CURSOR
CREATE TABLE #Stage ( ArticleID INT, CurrentItems INT, CurrentValue MONEY )

DECLARE @ArticleID INT, @PrevID INT = 0, @Items INT, @CurrItems INT, @Price MONEY, @LatestPrice MONEY, @Away INT, @Diff INT

DECLARE curYak CURSOR LOCAL FORWARD_ONLY FOR SELECT s.ArticleID, s.Items, s.Price, COALESCE(w.Items, 0) AS Away FROM ( SELECT ArticleID, TranDate, Items, Price FROM dbo.Stock WHERE TranCode IN ('IN', 'RET') ) AS s LEFT JOIN ( SELECT ArticleID, SUM(Items) AS Items FROM dbo.Stock WHERE TranCode = 'OUT' GROUP BY ArticleID ) AS w ON w.ArticleID = s.ArticleID ORDER BY s.ArticleID, s.TranDate

OPEN curYak

FETCH NEXT FROM curYak INTO @ArticleID, @Items, @Price, @Away

WHILE @@FETCH_STATUS = 0 BEGIN SELECT @Diff = CASE WHEN @ArticleID > @PrevID THEN 0 WHEN @CurrItems > @Away THEN @CurrItems - @Away ELSE @Diff END, @CurrItems = CASE WHEN @ArticleID > @PrevID THEN @Items ELSE @CurrItems + @Items - @Diff END, @PrevID = @ArticleID, @LatestPrice = COALESCE(@Price, @LatestPrice)

    IF @CurrItems &gt;= @Away
       INSERT    #Stage
         (
          ArticleID,
          CurrentItems,
          CurrentValue
         )
       VALUES    (
          @ArticleID,
          @CurrItems - @Away,
          (@CurrItems - @Away) * @LatestPrice
         )

    FETCH  NEXT
    FROM   curYak
    INTO   @ArticleID,
       @Items,
       @Price,
       @Away
END

CLOSE curYak DEALLOCATE curYak

SELECT ArticleID, SUM(CurrentItems) AS CurrentItems, SUM(CurrentValue) AS CurrentValue FROM #Stage GROUP BY ArticleID ORDER BY ArticleID

DROP TABLE #Stage
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answered Nov 11, 2009 at 04:47 PM

Peso gravatar image

Peso
1.6k 5 6 8

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asked: Oct 23, 2009 at 03:56 PM

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Last Updated: Nov 14, 2009 at 01:55 PM