ScalarCount.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using PX.SM;
using PX.TM;
using PX.Data;

namespace PX.Objects.CR
{
	public sealed class ScalarCount<Field> : IBqlFunction
		where Field : IBqlField
	{
		public void GetAggregates(List<IBqlFunction> fields)
		{
			//Return this as count is aggregate function
			fields.Add(this);
		}
		public void Parse(PXGraph graph, List<IBqlParameter> pars, List<Type> tables, List<Type> fields, List<IBqlSortColumn> sortColumns, StringBuilder text, BqlCommand.Selection selection)
		{
			if (tables != null)
			{
				tables.Add(typeof(int));
			}
			if (graph != null && text != null)
			{
				//adding count function to the field
				StringBuilder bld = new StringBuilder("COUNT(DISTINCT ");
				bld.Append(BqlCommand.GetSingleField(typeof(Field), graph, tables, selection, BqlCommand.FieldPlace.Condition));
				bld.Append(')');
			}
		}
		public void Verify(PXCache cache, object item, List<object> pars, ref bool? result, ref object value) { }
		//Return name of function
		public string GetFunction() { return "COUNT"; }
		//return name of field what we need to count
		public Type GetField() { return typeof(Field); ; }
		//it is not group by
		public bool IsGroupBy() { return false; }
	}
}