Databand sort numerics Nulls last

Comments

• ipong

  July 2018 edited 10:40AM

  there are 2 methods:
  a. easy way : custom function
  b. hard way : linq

  CustomSort1.frx 1.5K

  CustomSort2.frx 1.8K
• Gerd1965

  July 2018 edited July 2018

  ipong wrote: »

  there are 2 methods:
  a. easy way : custom function
  b. hard way : linq

  
  First of all I do not understand how do you create the datasource "nullable".
  Then my datasource is a datatable derived from MySQL database with many Columns. I could build a sorted list from it (if sorted list is supported), but I really do not understand the concept of the file you posted here.
  
  Is there a source for some material to learn about FR? I only can find outdated manuals.
• ipong

  July 2018 edited July 2018

  2 ways to create datasource:
  1. fastreport as standalone, pull data from database with built-in classes
  2. push data from main application (winforms, wpf, web apps) to fastreport
  
  i attached samples for demonstration:
  1. instagram.frx , standalone report, pull data from internet, a json format, don't forget to copy Newtonsoft.Json.dll into C:\Program Files\FastReports\FastReport.Net Trial, because the dll must exists along with designer.exe
  2. a console project, how to push data to fastreport and custom sort
  
  basically, two kinds of data object are processed internally by fastreport :
  1. business object (data model or data transfer object, whatever)
  a. if you pushed data from main app with code : report.RegisterData(list, "BODatasource");
  b. you can catch the object from report script : BusinessObjectDataSource data = Report.GetDataSource("BODatasource") as BusinessObjectDataSource;
  c. where is my business object?

      // declare a model in report script:
      class DataModel
      {
          public int? field1 { get; set; }
          public string field2 { get; set; }
      }
  

  and...

      private void _StartReport(object sender, EventArgs e)
      {
        DataSourceBase data = Report.GetDataSource("BODatasource");
        List<DataModel> list = (List<DataModel>)data.Reference;
      }
  

  
  2. datatable
  a. if you pushed data from main app with code : report.RegisterData(datatable "DataTableDatasource");
  b. you can catch the object from report script : TableDataSource data = Report.GetDataSource("DataTableDatasource") as TableDataSource;
  c. where is my datatable?

      private void _StartReport(object sender, EventArgs e)
      {
        DataSourceBase data = Report.GetDataSource("DataTableDatasource");
        DataTable table = (DataTable)data.Reference;
  
        // custom sort with linq
        // you must set reference to System.Data.DataSetExtensions.dll and System.Core.dll
        DataTable sortedTable = table.Rows.Cast<DataRow>().OrderBy(x => x[0] != DBNull.Value ? x[0] : 1000).CopyToDataTable();
        data.Reference = sortedTable;
      }
  

  FastReportDataSource.zip 5.4K

  instagram.frx 9.4K
• Gerd1965

  July 2018 edited 10:40AM

  ipong wrote: »

  2 ways to create datasource:
  1. fastreport as standalone, pull data from database with built-in classes
  2. push data from main application (winforms, wpf, web apps) to fastreport
  
  i attached samples for demonstration:
  1. instagram.frx , standalone report, pull data from internet, a json format, don't forget to copy Newtonsoft.Json.dll into C:\Program Files\FastReports\FastReport.Net Trial, because the dll must exists along with designer.exe
  2. a console project, how to push data to fastreport and custom sort
  
  basically, two kinds of data object are processed internally by fastreport :
  1. business object (data model or data transfer object, whatever)
  a. if you pushed data from main app with code : report.RegisterData(list, "BODatasource");
  b. you can catch the object from report script : BusinessObjectDataSource data = Report.GetDataSource("BODatasource") as BusinessObjectDataSource;
  c. where is my business object?

      // declare a model in report script:
      class DataModel
      {
          public int? field1 { get; set; }
          public string field2 { get; set; }
      }
  

  and...

      private void _StartReport(object sender, EventArgs e)
      {
        DataSourceBase data = Report.GetDataSource("BODatasource");
        List<DataModel> list = (List<DataModel>)data.Reference;
      }
  

  
  2. datatable
  a. if you pushed data from main app with code : report.RegisterData(datatable "DataTableDatasource");
  b. you can catch the object from report script : TableDataSource data = Report.GetDataSource("DataTableDatasource") as TableDataSource;
  c. where is my datatable?

      private void _StartReport(object sender, EventArgs e)
      {
        DataSourceBase data = Report.GetDataSource("DataTableDatasource");
        DataTable table = (DataTable)data.Reference;
  
        // custom sort with linq
        // you must set reference to System.Data.DataSetExtensions.dll and System.Core.dll
        DataTable sortedTable = table.Rows.Cast<DataRow>().OrderBy(x => x[0] != DBNull.Value ? x[0] : 1000).CopyToDataTable();
        data.Reference = sortedTable;
      }
  

  
  Sorry to bother you again...
  - type "DataTable" does not exist
  - I cannot find any hint how and where to set the mentioned references
  
  
  
• ipong

  July 2018 edited 10:40AM

  learn it from my attachment, full working visual studio project
• Gerd1965

  July 2018 edited 10:40AM

  when starting your project FastReportDataSource it throws Error in FastReport "Main class of report was not found in ReportScript"
• ipong

  July 2018 edited July 2018

  i dont have any clue what you did, works fine for me (visual studio 2017 v15.7.4)
• Gerd1965

  July 2018 edited July 2018

  I am using VS 2015 and VB as script language - but should this be the problem?
  
  As a workaround I added a datacolumn to my table where all Nulls are converted to 1000 and this works too.
  
  Something else: is it possible to hide a groupheader conditionally?
  I have a table with "GroupNumber" and "Divider". If Divider=Null then the GroupHeader should not be shown.
• ipong

  July 2018 edited July 2018

  i will prefer your method, adding datacolumn, why?, doing something in script is not optimized because fastreport use reflection to do that, in terms of speed, reflection is slow.
  
  for reference: https://benohead.com/three-options-to-dynam...te-csharp-code/
  
  dynamic class is a trade off between speed and flexibility/convenience.