Calculate number of any kind of entities in Acumatica - acumatica

Question

In Acumatica reference ( Help->Acumatica Framework -> API Reference -> BQL -> Grouping and Aggregating -> Aggregation Functions ) there is following fragment of code
PXResult<Table> res =
PXSelectGroupBy<Table, Aggregate<Count>>.Select(this).RowCount;
but when I execute it with entity UPCompany I'm receiving following error message:
System.ArgumentNullException was unhandled by user code
HResult=-2147467261
Message=Value cannot be null.
Source=mscorlib
StackTrace:
at System.RuntimeType.MakeGenericType(Type[] instantiation)
at PX.Data.Select4`2.OrderByNew(Type newOrderBy)
at PX.Data.PXView.prepareSorts(String[] sortcolumns, Boolean[] descendings, Object[] searches, Int32 topCount, Boolean& needOverrideSort, Boolean& anySearch, Boolean& resetTopCount)
at PX.Data.PXView.Select(Object[] currents, Object[] parameters, Object[] searches, String[] sortcolumns, Boolean[] descendings, PXFilterRow[] filters, Int32& startRow, Int32 maximumRows, Int32& totalRows)
at PX.Data.PXSelectBase`1.selectBound[Resultset](BqlCommand command, Boolean readOnly, PXGraph graph, Int32 startRow, Int32 totalRows, Object[] currents, Object[] pars)
at PX.Data.PXSelectBase`1.select[Resultset](BqlCommand command, Boolean readOnly, PXGraph graph, Int32 startRow, Int32 totalRows, Object[] pars)
at PX.Data.PXSelectGroupBy`2.SelectWindowed[Resultset](PXGraph graph, Int32 startRow, Int32 totalRows, Object[] pars)
at PX.Data.PXSelectGroupBy`2.Select[Resultset](PXGraph graph, Object[] pars)
at stackOverflowSync.UsrstackOverflowSettingsMaint.ItemsForSync(UsrstackOverflowSettings settingsSelect) in C:\sourceCode\stackOverflow\stackOverflow\Acumatica_ERPSync\Acumatica_ERPSync\stackOverflowSync\UsrstackOverflowSettingsMaint.cs:line 26
at stackOverflowSync.UsrstackOverflowSettingsMaint.Persist() in C:\sourceCode\stackOverflow\stackOverflow\Acumatica_ERPSync\Acumatica_ERPSync\stackOverflowSync\UsrstackOverflowSettingsMaint.cs:line 173
at PX.Data.PXSave`1.<Handler>d__2.MoveNext()
at PX.Data.PXAction`1.<Press>d__31.MoveNext()
InnerException:
so my question is the following: how to properly execute fragment of code from Acumatica reference in order to receive number of all rows including UPCompany?

Answer 1

I've found the reason. UPCompany is not entity that is workable with PXSelect, PXSelectGroupBy. I suppose maybe it's because UPCompany doesn't have direct correspondence with database. While it's strange but for other entities besides UPCompany PXSelect and PXSelectGroupBy works pretty well. I've ended with following method:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using PX.Data;
namespace PX.Data
{
public static class ExtMethods
{
public static int? GetNumberOfEntities<T>(this PXGraph graph) where T : class, IBqlTable, new()
{
PXResult<T> res = PXSelectGroupBy<T, Aggregate<Count>>.Select(graph);
return res.RowCount;
}
}
}
for calculating number of entities