Filtering over Sql.ExpressionMethod alike property having aggregate complex expression

Hi,

Similar to Sql.ExpressionMethod we have construct to create expressions assigned to scalar property. Grids are normally shown with this expression and it works fine, problem is when we want to filter this subquery linq Expression, e.g. . …where ChecklistTriggers like ‘%Hired%’ (ChecklistTrigger defined below)

We are having hundreds of Expressions for properties and we have issues with few of them using Association.Any + StringAggregate. If we remove checklist.ChecklistTriggers.Any call, it is working fine, but that is not correct for our business logic.

public <Func<Checklist, string>> ChecklistTriggers
{
      return checklist => checklist.ChecklistTriggers.Any()
          ? checklist.ChecklistTriggers.AsQueryable()
              .Select(x => x.TriggerType == TriggerType.Hired ? "Hired" :
                   x.TriggerType == TriggerType.PreHired ? "PreHired" :
                   x.TriggerType == TriggerType.Terminated ? "Terminated" : ""
              )
              .StringAggregate(",").ToValue()
           : "None";
}

For version 3.2.3. we get “The method or operation is not implemented.” and for 3.4.5. we get “Cannot perform an aggregate function on an expression containing an aggregate or a subquery.”. Query for 3.4.5. version seems complicated, instead of using subquery, it is duplicated for filter and for normal grid column, strange.

Using Coalesce did not help, the same error.

public <Func<Checklist, string>> ChecklistTriggers
{
      return checklist => checklist.ChecklistTriggers.AsQueryable()
              .Select(x => x.TriggerType == TriggerType.Hired ? "Hired" :
                   x.TriggerType == TriggerType.PreHired ? "PreHired" :
                   x.TriggerType == TriggerType.Terminated ? "Terminated" : ""
              )
              .StringAggregate(",").ToValue() ?? "None";
}

Environment details

linq2db version: 3.2.3. and 3.4.5. Database Server: Sql Server 2019 Database Provider: SQL Operating system: W10 .NET Framework: 4.8.2

[zbrkic]

Hi, here is an example:

using LinqToDB;
using LinqToDB.Mapping;
using System.Collections.Generic;
using System.Linq;

namespace Linq2dbTest
{
    public class FilteringTest
    {
        public void Test()
        {
            var builder = MappingSchema.Default.GetFluentMappingBuilder();

            builder.Entity<Checklist>()
                .HasTableName("Checklist")
                .HasSchemaName("Onboarding")
                .Property(x => x.Id).HasColumnName("ChecklistId").IsPrimaryKey()
                .Association(x => x.ChecklistTriggers, x => x.Id, x => x.ChecklistId, canBeNull: false);


            builder.Entity<ChecklistTrigger>()
                .HasTableName("ChecklistTriggers")
                .HasSchemaName("Onboarding")
                .HasIdentity(x => x.Id)
                .HasPrimaryKey(x => x.Id);


            using (var db = new Db())
            {
                var query = db.Checklist
                    .Select(x => new
                    {
                        x.Id,
                        Triggers = x.ChecklistTriggers.Any()
                            ? x.ChecklistTriggers.AsQueryable()
                                .Select(checklist => checklist.TriggerType == TriggerType.Hired ? "Hired" :
                                    checklist.TriggerType == TriggerType.PreHired ? "PreHired" :
                                    checklist.TriggerType == TriggerType.Terminated ? "Terminated" : "")
                                .StringAggregate(",").ToValue()
                        : "None"
                    });

                var good = query.ToList();
                var bad = query.Where(x => x.Triggers.Contains("H")).ToList();
            }
        }

        public class Db: LinqToDB.Data.DataConnection
        {
            public Db() : base(ProviderName.SqlServer2017, "data source=localhost;initial catalog=xxx;integrated security=True;MultipleActiveResultSets=True") { }
            public ITable<Checklist> Checklist => GetTable<Checklist>();
            public ITable<ChecklistTrigger> ChecklistTrigger => GetTable<ChecklistTrigger>();
        }

        public class Checklist
        {
            public virtual int Id { get; set; }
            public virtual ICollection<ChecklistTrigger> ChecklistTriggers { get; set; }
        }

        public class ChecklistTrigger
        {
            public virtual int Id { get; set; }
            public virtual int ChecklistId { get; set; }
            public virtual TriggerType TriggerType { get; set; }
        }

        public enum TriggerType
        {
            Hired = 1,
            PreHired = 2,
            Terminated = 3
        }
    }
}

[MaceWindu]

Probably next thursday