using System;

public class Program

{

    public static void Main()

    {

        var program = new Program();

​

        program.getDBOptionOne();

        program.getDBOptionTwo();

        program.getDBOptionThree();

        program.sqlLogger();

    }

    public async void getDBOptionTwo(){

        var dbEntities = await _dbContext.CP_Entities

            .Where(e => some_initial_conditions) // Filter broadly

            .ToListAsync(); // Fetch to memory

​

        var allEntities = dbEntities

            .Where(e => complex_condition_here) // Process complex logic in memory

            .ToList();

    }

    public async void sqlLogger(){

        optionsBuilder.LogTo(Console.WriteLine, LogLevel.Information);

    }

    public async void getDBOptionThree(){

        var part1 = _dbContext.CP_Entities

            .Where(e => condition1)

            .ToList();

​

        var part2 = _dbContext.CP_Entities

            .Where(e => condition2)

            .ToList();

​

​

        var combined = part1.Concat(part2).Distinct().ToList();

    }

    public async void getDBOptionOne(){

        // Step 1: Fetch the legal entity directly

        var legalEntities = sellSideEntity != null 

            ? await _dbContext.CP_Entities

                .Where(e => e.EntityType == (int)EntityType.LegalEntity && e.EntityId == sellSideEntity.EntityId)

                .ToListAsync()

            : new List<CP_Entity>();

​

        // Step 2: Fetch investment manager selection

        var investmentManagerSelection = await _dbContext.CP_Entities

            .Where(e => e.EntityType == (int)EntityType.InvestmentManager

                        && investmentManagerIds.Contains(e.UID)

                        && e.FirmId == _fundProgressLaunchData.BuySideFirmId

                        && e.ActiveStatus != (int)EntityActiveStatus.Inactive)

            .ToListAsync();

​

        // Step 3: Fetch manager entity selection

        var managerEntitySelection = await _dbContext.CP_Entities

            .Where(e => e.FirmId == _fundProgressLaunchData.SellSideFirmId

                        && e.EntityType == _fundProgressLaunchData.BuySideFirmId

                        && e.ParentEntityId == null

                        && e.ActiveStatus != (int)EntityActiveStatus.Inactive)

            .ToListAsync();

​

        // Step 4: Fetch mandate funds

        var mandateFunds = fundWithDetail != null

            ? await _dbContext.CP_Entities

                .Where(e => fundWithDetail.Any(f => f.InvestmentManagerUId == e.UID || f.ManagingInvestmentManagerUID == e.UID))

                .ToListAsync()

            : new List<CP_Entity>();

​

        // Step 5: Fetch investment managers

        var investmentManagers = investmentManagerFundsUIds != null

            ? await _dbContext.CP_Entities

                .Where(e => e.EntityType == (int)EntityType.InvestmentManager && investmentManagerFundsUIds.Contains(e.UID))

                .ToListAsync()

            : new List<CP_Entity>();

​

        // Combine all results

        var allEntities = legalEntities

            .Concat(investmentManagerSelection)

            .Concat(managerEntitySelection)

            .Concat(mandateFunds)

            .Concat(investmentManagers)

            .Distinct()

            .ToList();

​

    }

}