tsql - sql server - transforming data with dynamic pivot -


this question has answer here:

i need dynamically transform data in table #table format:

 spot_id        name        pct -------        ----        --- 1                         2 1               b           8 1               c           6 2                         4 2               b           5 3                         5 3               d           1 3               e           4

to: 

 spot_id         b     c     d     e -------    ---   ---   ---   ---   --- 1           2     5     6     0     0 2           4     5     0     0     0 3           5     0     0     1     4

the thing don't know in advance values of column "name" or how many of them there are, think have use kind of dynamic sql pivoting

just figured out how solve problem:

  declare @cols nvarchar(max),     @query  nvarchar(max)  select @cols = stuff((select ',' + quotename(name)                      (select distinct name #table) t             xml path(''), type             ).value('.', 'nvarchar(max)')          ,1,1,'')  set @query = n'select spot_id,' + @cols + n'               (                 select spot_id, name, pct                 #table             ) x             pivot              (                 max(pct)                 name in (' + @cols + n')             ) p '  exec sp_executesql @query;

if there more elegant way same?

declare @t table (spot int,name varchar(1),pct int) insert @t(spot,name,pct)values(1,'a',2),(1,'b',8),(1,'c',6),(2,'a',4),(2,'b',5),(3,'a',5),(3,'d',1),(3,'e',4)   select spot,isnull([a],0)[a],isnull([b],0)[b],isnull([c],0)[c],isnull([d],0)[d],isnull([e],0)[e] (select spot,pct,name @t)t pivot(max(pct) name in ([a],[b],[c],[d],[e]))p   select spot,isnull(max(case when name = 'a' pct end),0)a,isnull(max(case when name = 'b' pct end),0)b , isnull(max(case when name = 'c' pct end),0)c , isnull(max(case when name = 'd' pct end),0)d ,isnull(max(case when name = 'e' pct end),0)e  @t group spot

using dynamic query : 

if object_id('tempdb..#t') not null     drop table #t  create  table #t(spot int,name varchar(1),pct int) insert #t(spot,name,pct)values(1,'a',2),(1,'b',8),(1,'c',6),(2,'a',4),(2,'b',5),(3,'a',5),(3,'d',1),(3,'e',4)  declare @statement nvarchar(max) ,@columns nvarchar(max)  select @columns = isnull(@columns + ', ', '') + n'[' + tbl.name + ']' (    select distinct name    #t    ) tbl  select @statement = ' select spot,isnull([a],0)[a],isnull([b],0)[b],isnull([c],0)[c],isnull([d],0)[d],isnull([e],0)[e] (select spot,pct,name #t)t pivot(max(pct) name in (' + @columns + ')) pvt'  exec sp_executesql @statement = @statement

Comments

Post a Comment

Popular posts from this blog

powershell Start-Process exit code -1073741502 when used with Credential from a windows service environment -

i'm running strange behavior powershell start-process call. here call: $process = start-process ` "c:\somepath\mybinary.exe" ` -passthru ` -credential $defaultcredential ` -wait ` -workingdirectory "c:\somepath" ` -loaduserprofile if ($process.exitcode -ne 0) { #do } this call return exit code - 1073741502 . after quick search, exit code seems related generic error when program not load required dll (aka. status_dll_init_failed ). when run without -credential $credential program runs correctly. in order isolate problem, manually launched some.exe in prompt target credential , runs smoothly. so problem seems come way start-process cmdlet launch process. i found potential solutions problem tried apply no luck : link , link . would have idea of what's going on here ? edit 1: run proc mon monitoring program activities when launched directly or via powershell script. problem seems occur when loading kernelbase
Read more

twig - Using Twigbridge in a Laravel 5.1 Package -

i'm trying create laravel 5.1 package uses twigbridge instead of .php views. can normal .php views display fine, when try make use of .twig templates i'm met error. possible use twigbridge templates when creating views laravel package or pretty stuck blade , php ? edit 1: loading twig template without extending works. it's when start using {% extends 'file' %} error comes out. i error error loading /virtual/laravel/packages/username/mypackage/src/views/sample.twig: template "templates.master" not defined () in "/virtual/laravel/packages/username/mypackage/src/views/sample.twig" @ line 1. my folders username |_ mypackage |_ src |_ controllers - samplecontroller.php |_ views |_ templates - master.twig - sample.twig twig template sample.twig {% extends 'templates.master' %} {% block content %} {{ parent()
Read more

c# - LINQ join Entities from HashSet's, Join vs Dictionary vs HashSet performance -

i have hashset's each stores t, have written test application compares different relation algorithms can think of, i'm not pleased results getting. does there exist more efficient ways of achieving object relations, once testing? using system; using system.collections.generic; using system.linq; using system.text; using system.threading.tasks; using system.diagnostics; namespace linqtests { class program { static void main(string[] args) { hashset<user> usertable = new hashset<user>(); hashset<userproperty> userpropertytable = new hashset<userproperty>(); #region lets create dummy data. console.writeline("please wait while creating dummy data, can take while..."); console.writeline(""); int rows = 1000000; for(int x = 0; x < rows; x++) { random rnd = new random(); // ad
Read more