a query like factorial

  • Hi.

    I ask you for help because its more than 2 days im thinking about this question.

    Imagine we have a table like this:

    ID | Value

    ---------

    1 | 19

    2 | 90

    3 | 20

    4 | 8

    5 | 9

    I want my query make this output:

    ID | Value

    ---------

    1 | 19

    2 | 19 + 90

    3 | 19 + 90 +20

    4 | 19 + 90 +20 + 8

    5 | 19 + 90 +20 + 8 + 9

    I already tried so many queries, the last query I wrote are this but it dont make correct output:

    WITH CTE (rowNum,Value,Level) AS

    (

    SELECT ROW_NUMBER() OVER (ORDER BY ID DESC) as rowNum,

    Value

    0 as Level

    FROM Mytable

    WHERE ID = (SELECT MIN(ID) FROM Mytable)

    UNION ALL

    SELECT ROW_NUMBER() OVER (ORDER BY ID DESC) as rowNum,

    Value

    Level + 1

    FROM Mytable a INNER JOIN CTE b ON b.rowNum <= a.rowNum + 1 --a.rowNum are not allowed here

    )

    SELECT rowNum, SUM(Value)

    FROM CTE

    GROUP BY LEVEL, rowNum

    Thank you for help

    ___________________________________
    Computer Enterprise Masoud Keshavarz
    I don't care about hell.
    If I go there I've played enough Diablo to know how to fight my way out.

  • Something like this maybe?

    DECLARE @factorial VARCHAR(255)

    SET @factorial = ''

    CREATE TABLE #temp

    (

    id INT,

    value VARCHAR(255)

    )

    INSERT INTO #temp

    (id,

    value)

    SELECT 1,

    '19'

    UNION

    SELECT 2,

    '90'

    UNION

    SELECT 3,

    '20'

    UNION

    SELECT 4,

    '8'

    UNION

    SELECT 5,

    '9'

    UPDATE #temp

    SET @factorial = value = ( CASE

    WHEN @factorial <> '' THEN @factorial + ' + '

    ELSE @factorial

    END ) + value

    SELECT *

    FROM #temp

    DROP TABLE #temp

  • Hi

    Jeff Moden wrote a comprehensive article which covers what you want to do and investigates the various methods used

    http://www.sqlservercentral.com/articles/T-SQL/68467/

    Here's an example using the triangular join method and the quirky update method

    SELECT * INTO #MyTable

    FROM (VALUES(1,19), (2,90), (3,20), (4,8), (5, 9)) AS M(ID, VALUE)

    -- triangular join

    select ID

    , VALUE

    , (

    SELECT SUM(VALUE)

    FROM #MyTable b

    WHERE b.ID <= a.ID

    ) AS RUNNING_TOTAL

    FROM #MyTable a

    -- quirky update

    ALTER TABLE #MyTable ADD CONSTRAINT mt_pk PRIMARY KEY (ID)

    ALTER TABLE #MyTable ADD RUNNING_TOTAL INT

    ALTER TABLE #MyTable ADD RUNNING_CALC VARCHAR(100)

    DECLARE @runningTotal int = 0

    DECLARE @runningCalc varchar(100) = null

    UPDATE #MyTable

    SET @runningTotal = RUNNING_TOTAL = @runningTotal + VALUE

    ,@runningCalc = RUNNING_CALC = isnull(@runningCalc + ' + ','') + CAST(VALUE AS VARCHAR(10))

    SELECT * FROM #MyTable

    DROP TABLE #MyTable

  • if you just want to concatenate the values from a given table you can try this :

    CREATE TABLE #temp

    (

    id INT,

    value NVARCHAR(255)

    )

    INSERT INTO #temp (id,value) SELECT 1, '19'

    INSERT INTO #temp (id,value) SELECT 2, '90'

    INSERT INTO #temp (id,value) SELECT 3, '20'

    INSERT INTO #temp (id,value) SELECT 4, '8'

    INSERT INTO #temp (id,value) SELECT 5, '9'

    with cte

    as (select id, value from #temp where id =1

    union all

    select t.id, convert (nvarchar(255),c.value+'+'+t.value)

    from #temp t inner join ctec on c.id= (t.id-1))

    select * from cte

    if you want the sums returned. you must only change the data type of the value column and remove the +'+'+

    There is always something new to learn.
    My personal SQL Blog[/url]

  • Whoa!!! Who said anything about the OP storing the VALUE as a character based data type??? :blink:

    @Masoud,

    Take a gander at the article at the first link in my signature line below. Posting an example CREATE TABLE and readily consumable data will help folks answer your question much more quickly and more more accurately.

    --Jeff Moden


    RBAR is pronounced "ree-bar" and is a "Modenism" for Row-By-Agonizing-Row.
    First step towards the paradigm shift of writing Set Based code:
    ________Stop thinking about what you want to do to a ROW... think, instead, of what you want to do to a COLUMN.

    Change is inevitable... Change for the better is not.


    Helpful Links:
    How to post code problems
    How to Post Performance Problems
    Create a Tally Function (fnTally)

  • Try this, but not really sure since the expected output is not entirely certain based on the thread

    /*ID | Value

    ---------

    1 | 19

    2 | 90

    3 | 20

    4 | 8

    5 | 9

    */

    DECLARE @valuestab TABLE (ID INT,VALUE INT)

    INSERT INTO @valuestab

    ( ID, VALUE )

    VALUES ( 1,19

    ),(2,90),(3,20),(4,8),(5,9);

    WITH CTE (ID,Value) AS

    (

    SELECT ID,

    Value

    FROM @valuestab

    UNION ALL

    SELECT a.id,

    a.Value + b.Value

    FROM @valuestab a

    INNER JOIN CTE b

    ON b.ID +1 = a.ID

    )

    SELECT ID, MAX(Value) AS Value

    FROM CTE

    GROUP BY ID

    Jason...AKA CirqueDeSQLeil
    _______________________________________________
    I have given a name to my pain...MCM SQL Server, MVP
    SQL RNNR
    Posting Performance Based Questions - Gail Shaw[/url]
    Learn Extended Events

  • Thank you Horatiu, mickyT, Erin Ramsay for your time and help.

    @SQLRNNR

    May you help me to trace your code on paper please?

    Im a newbie and im not sure how does it work.

    In my real table ID is NOT sequential. Thats why I tried to generate row number using ROW_NUMBER() function.

    First, I think you forget to write WHERE statement in anchor and you meant something like this:

    WITH CTE (ID,Value) AS

    (

    SELECT ID,

    Value

    FROM @valuestab

    WHERE ID = (SELECT MIN(ID) FROM @valuestab) --I guess you forget this line

    UNION ALL

    So your anchor should generate this output:

    ID|Value

    --------

    1 | 19

    Now we must union anchor with second part of query until it satisfied all rows.

    At first run this condition b.ID +1 = a.ID change our table to this:

    ID|Value

    --------

    1 | 19

    2 | 19 + 90

    Now it makes me confused. Once again we should check this condition b.ID +1 = a.ID

    Does it check this condition only on last row or it check it on all rows?

    If it check it on all rows it should generate this output:

    ID|Value

    --------

    1 | 19

    2 | 19 + 90

    2 | 19 + 90 <-----surplus

    3 | 19 + 90 + 20

    I have problem with recursive statements, I know what is this, I know how we should write it.

    But I still have logical problem with its mechanism.

    Thank you for help.

    ___________________________________
    Computer Enterprise Masoud Keshavarz
    I don't care about hell.
    If I go there I've played enough Diablo to know how to fight my way out.

  • How about:

    IF OBJECT_ID('MyTable') IS NOT NULL

    DROP TABLE MyTable

    GO

    SELECT * INTO MyTable

    FROM (VALUES(1,19), (2,90), (3,20), (4,8), (5, 9)) AS M(ID, VALUE)

    GO

    SELECTm.Id, SUM(m2.Value)

    FROMMytable m

    JOINMytablem2ON m2.ID <= m.id

    GROUP BY m.Id

  • schleep (3/19/2013)


    How about:

    IF OBJECT_ID('MyTable') IS NOT NULL

    DROP TABLE MyTable

    GO

    SELECT * INTO MyTable

    FROM (VALUES(1,19), (2,90), (3,20), (4,8), (5, 9)) AS M(ID, VALUE)

    GO

    SELECTm.Id, SUM(m2.Value)

    FROMMytable m

    JOINMytablem2ON m2.ID <= m.id

    GROUP BY m.Id

    That will definitely work... for a while. It's what's known as a "Triangular Join". Please see the following article as to why it shouldn't be used.

    http://www.sqlservercentral.com/articles/T-SQL/61539/

    --Jeff Moden


    RBAR is pronounced "ree-bar" and is a "Modenism" for Row-By-Agonizing-Row.
    First step towards the paradigm shift of writing Set Based code:
    ________Stop thinking about what you want to do to a ROW... think, instead, of what you want to do to a COLUMN.

    Change is inevitable... Change for the better is not.


    Helpful Links:
    How to post code problems
    How to Post Performance Problems
    Create a Tally Function (fnTally)

  • Yikes. Thanks for pointing that out Jeff.

    I've only (reluctantly) used it with very small sets, mostly in pre-2K5 code.

    I'll be checking my code now...

  • schleep (3/19/2013)


    Yikes. Thanks for pointing that out Jeff.

    I've only (reluctantly) used it with very small sets, mostly in pre-2K5 code.

    I'll be checking my code now...

    You bet and thanks for the feedback.

    If you have something big, a properly configured "Quirky Update" is both bullet-proof and lightning quick. It'll process a million rows in less than 3 seconds on most machines. There are some pretty strict rules to follow to make sure it doesn't go "quirky" on you, but it's usually worth it. It even beats the new functionality they added to SUM() OVER in 2012. It is, however, unsupported and if that's a problem for someone, then just use a recursive CTE or even a fire-hose cursor (likely better than the rCTE but haven't tested it) to do the running total.

    --Jeff Moden


    RBAR is pronounced "ree-bar" and is a "Modenism" for Row-By-Agonizing-Row.
    First step towards the paradigm shift of writing Set Based code:
    ________Stop thinking about what you want to do to a ROW... think, instead, of what you want to do to a COLUMN.

    Change is inevitable... Change for the better is not.


    Helpful Links:
    How to post code problems
    How to Post Performance Problems
    Create a Tally Function (fnTally)

  • masoudk1990 (3/19/2013)


    Thank you Horatiu, mickyT, Erin Ramsay for your time and help.

    @SQLRNNR

    May you help me to trace your code on paper please?

    Im a newbie and im not sure how does it work.

    In my real table ID is NOT sequential. Thats why I tried to generate row number using ROW_NUMBER() function.

    First, I think you forget to write WHERE statement in anchor and you meant something like this:

    WITH CTE (ID,Value) AS

    (

    SELECT ID,

    Value

    FROM @valuestab

    WHERE ID = (SELECT MIN(ID) FROM @valuestab) --I guess you forget this line

    UNION ALL

    So your anchor should generate this output:

    ID|Value

    --------

    1 | 19

    Now we must union anchor with second part of query until it satisfied all rows.

    At first run this condition b.ID +1 = a.ID change our table to this:

    ID|Value

    --------

    1 | 19

    2 | 19 + 90

    Now it makes me confused. Once again we should check this condition b.ID +1 = a.ID

    Does it check this condition only on last row or it check it on all rows?

    If it check it on all rows it should generate this output:

    ID|Value

    --------

    1 | 19

    2 | 19 + 90

    2 | 19 + 90 <-----surplus

    3 | 19 + 90 + 20

    I have problem with recursive statements, I know what is this, I know how we should write it.

    But I still have logical problem with its mechanism.

    Thank you for help.

    The where clause in the anchor was not forgotten. It was unnecessary.

    You are going to need to provide a representative data sample and table structure if you want a different solution.

    Based on the data you provided, the script works. But if you are looking for something different, you need to write out exactly what you are trying to do.

    Jason...AKA CirqueDeSQLeil
    _______________________________________________
    I have given a name to my pain...MCM SQL Server, MVP
    SQL RNNR
    Posting Performance Based Questions - Gail Shaw[/url]
    Learn Extended Events

  • Sorry for replying after so long, but I found an easy solution for this and I liked to share it here, perhaps it help someone in future.

    DECLARE @factorial int

    SET @factorial = 0

    UPDATE tableName

    SET @factorial = value = @factorial + value --value is column name

    If you want to store factorial value in seperate column in each row:

    DECLARE @factorial int

    SET @factorial = 0

    UPDATE tableName

    SET @factorial = seperateColumn = @factorial + value --value is column name

    ___________________________________
    Computer Enterprise Masoud Keshavarz
    I don't care about hell.
    If I go there I've played enough Diablo to know how to fight my way out.

  • That what a "quirky update" is about...

    But!

    To make it bullet-proof you need to read J.Moden article and see what else should be added into your query, so it will always work properly (eg. clustered index and MAXDOP 1).

    Otherwise, you may find surprising that sometimes you will end up with unexpected results...

    _____________________________________________
    "The only true wisdom is in knowing you know nothing"
    "O skol'ko nam otkrytiy chudnyh prevnosit microsofta duh!":-D
    (So many miracle inventions provided by MS to us...)

    How to post your question to get the best and quick help[/url]

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