Dynamic column names

[Myxomopka666]

Greetings,

I have couple of SQL models that facilitate data for coluple different views.
What I`m trying to acheve is dynamically to set column names based on the current date
Here is an example.
Lets say that current date is 31-01-2000. I have 5 columns that I need to rename. My query returns the columns from first row. In report they should looks like second row.

In one of the models in "Pre Load Sciprt" I have the following code `

@using System.Data
@{
    ReportModel model = Model;
	ReportExecutionLog log = model.Report;
    List<ReportElement> elements = model.Elements;
    List<ReportRestriction> restrictions = model.Restrictions;
    
    DateTime currentDate = DateTime.Now;
    
    int lastDateElementNumber = -1;
    for (int i = 0; i < elements.Count; i++)
    {
        log.LogMessage($"{elements[i].Name}");
        if (elements[i].Name == "CURRENT_RUN")
            {
                lastDateElementNumber = i;
                break;
            }
    }
    var date_diff = 0;
    if (lastDateElementNumber > -1)
        {
            for (int y = lastDateElementNumber; y < elements.Count; y++)
                {
                    elements[y].DisplayName =currentDate.AddDays(-date_diff).ToString("yyyy-MM-dd");
                    date_diff = date_diff + 1;
                }
        }

    log.LogMessage("Processing the model 'Pre load script'");

}

` In one report that code works. In second report same code same code applied to SQLmodel1 gives an error but the error is in SQLmodel2 Error detail:
Object reference not set to an instance of an object.

Could you please help me understand what I`m doing wrong ?

[ariacom]

To debug this, just comment part of your script to see where the problem is located.
However, to change the result table, I would recommend to use a Task and to modify directly the ResultCell of the DataTable, here is one of the Sample to do it:

@using System.Data
@using System.Data.Common
@{
    //Format final result cells before rendering
    ReportTask task = Model;
    Report report = task.Report;   
    //Note that this Task MUST BE executed at the step: 'Models generated, before rendering'
    foreach (var model in report.Models) 
    {
        foreach (var page in model.Pages) 
        {
            //Format page result table
            foreach (var line in page.PageTable.Lines) 
            {
                foreach (var cell in line) 
                {
                    if (cell.IsTitle) {
                        cell.FinalCssStyle = "font-size:20px;color:blue;";
                    }
                }
            }       
            //Format data result table
            foreach (var line in page.DataTable.Lines) 
            {
                foreach (var cell in line) 
                {
                    if (cell.Element != null && cell.Element.IsNumeric && cell.DoubleValue < 0) {
                        cell.FinalCssStyle = "font-weight:bold;color:red;";
                    }
                }
            }       
        }
    }
}

[Myxomopka666]

Thanks for the reply ... I`ll check it :)