unpivot dynamic columns

  • hi

    i have a table which i need to unpivot. It is always in 2 year ranges (months) so looks something like:

    AccountId, StockId, 2013 - Jan, 2013 - feb, 2013 - mar...., 2014 - Jan, 2014 - feb, 2014 - mar....

    The year can be any Year but will always be for the year selected and the following year, so 24 columns.

    how can i unpivot this to look like:

    Account Id....StockId..........Date...............Value

    AC123..........STK123..........Jan - 2013.......1000

    AC123..........STK123..........Feb - 2013.......1150

    AC123..........STK123..........Mar - 2013.......2000

    AC123..........STK123..........Jan - 2014.......1400

    AC123..........STK123..........Feb - 2014.......900

    AC123..........STK123..........Mar - 2014.......2100

    thanks

  • If I assume that you could do this if you knew the names of the columns, the problem reduces to getting the names of the columns and then assembling them into the query string and executing it.

    Column names can be extracted (in their correct order) from information_schema.columns. Try running this:

    select table_name

    ,column_name

    ,ordinal_position

    ,data_type

    from information_schema.columns

    order by 1

    ,3

    Now we have to resort to dynamic SQL... There may be another way but none comes to mind.

    Put your various column names into local variables and then build your SQL string from them.

    And finally,

    Exec(@sql_string)

    If you haven't even tried to resolve your issue, please don't expect the hard-working volunteers here to waste their time providing links to answers which you could easily have found yourself.

  • Thats just what I was after. I can create the dynamic column string from here. Thanks.

  • Could you post DDL and sample data on the way of INSERT statements so we can work directly on it?

    Luis C.
    General Disclaimer:
    Are you seriously taking the advice and code from someone from the internet without testing it? Do you at least understand it? Or can it easily kill your server?

    How to post data/code on a forum to get the best help: Option 1 / Option 2
  • ok here's the completed solution, thanks to all who helped....

    -- destroy staging table if exists

    IF OBJECT_ID('tbl_TestTable', 'U') IS NOT NULL

    begin

    DROP TABLE tbl_TestTable

    end

    -- create the temp table

    create table tbl_TestTable(

    AccountId varchar(6),

    StockId varchar(7),

    [Jan - 2013] int,

    [Feb - 2013] int,

    [Mar - 2013] int,

    [Apr - 2013] int,

    [May - 2013] int,

    [Jun - 2013] int,

    [Jul - 2013] int,

    [Aug - 2013] int,

    [Sep - 2013] int,

    [Oct - 2013] int,

    [Nov - 2013] int,

    [Dec - 2013] int,

    [Jan - 2014] int,

    [Feb - 2014] int,

    [Mar - 2014] int,

    [Apr - 2014] int,

    [May - 2014] int,

    [Jun - 2014] int,

    [Jul - 2014] int,

    [Aug - 2014] int,

    [Sep - 2014] int,

    [Oct - 2014] int,

    [Nov - 2014] int,

    [Dec - 2014] int

    )

    -- insert some values

    insert into tbl_TestTable

    select 'AC1234', 'STK1111', 4284, 4946, 4773, 1812, 1121, 3977, 2453, 1229, 4448, 4844, 3460, 3299, 3715, 1082, 4335, 1024, 3363, 4565, 2096, 4482, 4282, 4539, 3638, 2061 union

    select 'AC1234', 'STK1112', 3543, 1854, 2986, 1249, 3105, 1799, 3425, 1620, 1209, 2872, 1737, 1886, 2114, 4249, 4924, 4936, 3008, 4339, 4043, 3151, 4302, 2721, 2677, 4177 union

    select 'AC1234', 'STK1113', 4184, 4376, 1101, 4746, 1117, 1846, 4379, 2953, 1956, 3053, 3749, 3753, 1924, 1698, 1311, 2688, 4144, 4174, 4481, 4660, 1326, 2990, 3830, 4573 union

    select 'AC1234', 'STK1114', 3881, 1936, 4198, 2471, 3815, 4555, 3502, 4989, 4880, 2727, 3440, 2434, 3362, 1552, 1188, 1221, 3431, 4134, 1526, 2839, 3856, 4577, 4226, 4769 union

    select 'AC1234', 'STK1115', 1444, 1679, 1569, 2278, 2120, 2308, 3436, 1134, 4062, 2198, 2233, 3644, 1784, 1701, 2965, 2433, 2798, 3474, 3025, 2333, 2170, 3255, 3259, 2904 union

    select 'AC4321', 'STK1111', 2359, 2618, 2941, 4887, 3570, 1946, 2350, 2322, 2472, 2813, 2791, 3035, 2886, 1849, 4087, 3182, 1103, 2213, 2003, 4447, 1167, 2249, 2064, 1370 union

    select 'AC4321', 'STK1112', 2684, 2542, 1095, 1584, 2153, 4382, 2599, 1515, 2640, 3967, 2325, 1661, 3847, 2485, 4534, 2696, 3549, 4411, 1651, 1146, 2570, 3716, 3877, 3361 union

    select 'AC4321', 'STK1113', 1663, 1538, 1377, 4045, 3626, 1488, 2471, 1447, 4196, 2438, 1361, 1259, 2255, 1744, 3991, 4205, 3717, 1700, 3254, 3190, 1218, 1651, 2111, 2768 union

    select 'AC4321', 'STK1114', 4989, 3589, 2524, 3803, 1684, 4717, 3292, 3051, 3050, 4871, 2815, 4892, 2717, 1647, 2355, 4823, 3194, 1197, 3814, 2178, 4276, 4943, 1638, 1254 union

    select 'AC4321', 'STK1115', 1226, 1261, 1900, 4854, 1699, 4810, 4957, 4280, 2799, 3956, 3352, 4196, 1723, 2208, 1560, 4367, 3610, 3876, 3745, 1892, 1224, 1449, 1356, 4300

    select * from tbl_TestTable

    -- create the dynamic date columns string

    declare @cols AS NVARCHAR(MAX)

    select @cols = STUFF((SELECT ',' + QUOTENAME(column_name)

    FROM (

    -- get columns as a list (THANKS FOR THIS Phil Parkin)

    selecttable_name, column_name, ordinal_position, data_type

    frominformation_schema.columns

    wheretable_name = 'tbl_TestTable'

    andordinal_position not in (1,2)

    ) cols

    ORDER BY ordinal_position

    FOR XML PATH(''), TYPE).value('.', 'NVARCHAR(MAX)'),1,1,''

    )

    select @cols as ColString

    -- finally do the unpivot using dynamic sql

    declare @sqlStr nvarchar(max)

    set @sqlStr = N'

    select AccountId, StockId, Col as Date, Quantity

    from(

    select AccountId, StockId, ' + @cols + '

    from tbl_TestTable

    ) as cp

    unpivot

    (

    Quantity for Col in (' + @cols + ')

    ) as up'

    exec sp_executesql @sqlStr

    -- kill the temp table

    drop table tbl_TestTable

  • spin (12/6/2013)


    ok here's the completed solution, thanks to all who helped....

    Nice work, well done.

    If you haven't even tried to resolve your issue, please don't expect the hard-working volunteers here to waste their time providing links to answers which you could easily have found yourself.

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