kommissar Posts - Answer Overflow

kommissar

•Created by kommissar on 2/6/2023 in #help

❔ How do I make part of a Linq query optional?

I have a query like this:

var newInfo = from ops in _radanContext.RouteCardOps
              join rc in _radanContext.RouteCards on ops.RouteNo equals rc.RouteNo
              join con in _radanContext.Contracts on rc.ContractNo equals con.ContractNo
              join parts in _radanContext.Parts on new { rc.PartNum, rc.Issue } equals new { parts.PartNum, parts.Issue }
              select new CompletedJobResult
              {
                  RouteNo = rc.RouteNo,
                  Seq = ops.Seq,
                  OpCode = ops.OpCode,
                  Issue = rc.Issue,
                  Description = ops.RouteDesc,
                  BatchQty = rc.BatchQty,
                  Qtycomplete = ops.QtyComplete,
                  ContractNo = con.ContractNo,
                  CustCode = con.CustCode,
                  PartNum = parts.Description,
                  BatchNo = rc.BatchNo
              };

var newInfo = from ops in _radanContext.RouteCardOps
              join rc in _radanContext.RouteCards on ops.RouteNo equals rc.RouteNo
              join con in _radanContext.Contracts on rc.ContractNo equals con.ContractNo
              join parts in _radanContext.Parts on new { rc.PartNum, rc.Issue } equals new { parts.PartNum, parts.Issue }
              select new CompletedJobResult
              {
                  RouteNo = rc.RouteNo,
                  Seq = ops.Seq,
                  OpCode = ops.OpCode,
                  Issue = rc.Issue,
                  Description = ops.RouteDesc,
                  BatchQty = rc.BatchQty,
                  Qtycomplete = ops.QtyComplete,
                  ContractNo = con.ContractNo,
                  CustCode = con.CustCode,
                  PartNum = parts.Description,
                  BatchNo = rc.BatchNo
              };

My problem is that the contracts should be optional - as sometimes rc.ContractNo can be null. How can I achieve this?

5 replies

CC#

•Created by kommissar on 2/6/2023 in #help

Entity Framework - DbUpdateConcurrencyException due to a trigger on the table

I've been dealing with a problem for a very long time, and I've got no idea how to fix it. I'm a bit of a noob at Entity Framework, so any help appreciated.

Microsoft.EntityFrameworkCore.DbUpdateConcurrencyException: Database operation expected to affect 1 row(s) but actually affected 0 row(s). Data may have been modified or deleted since entities were loaded. See http://go.microsoft.com/fwlink/?LinkId=527962 for information on understanding and handling optimistic concurrency exceptions.

Microsoft.EntityFrameworkCore.DbUpdateConcurrencyException: Database operation expected to affect 1 row(s) but actually affected 0 row(s). Data may have been modified or deleted since entities were loaded. See http://go.microsoft.com/fwlink/?LinkId=527962 for information on understanding and handling optimistic concurrency exceptions.

After a very long period of trial and error, I found that the table has a trigger on it, which must update some entities. The result is the above exception. I have no idea how to fix this, my code is extremely simple.

public async Task<Response<bool>> Handle(UpdateLastOperationCommand request, CancellationToken cancellationToken)
{
    var routeCard = await _myDbContext.RouteCards.FirstOrDefaultAsync(n => n.RouteNo == request.RouteNo);
    var routeOperations =
        await _myDbContext.RouteCardOps.Where(n => n.RouteNo == request.RouteNo).ToListAsync();
    var ordered = routeOperations.OrderBy(n => n.Seq);
    var lastOp = ordered.LastOrDefault();

    if (lastOp == null)
    {
        return new Response<bool>() { Succeeded = true, Data = false, Message = "No operation to update" };
    }

    routeCard.QtyFinished = lastOp.QtyComplete;
    if (routeCard.QtyFinished >= routeCard.BatchQty)
    {
        Log.Information($"RouteCard should be marked as complete");
        routeCard.RouteStatus = "CMP";
        routeCard.StatusDate = DateTime.Now;
        routeCard.CompletedDate = DateTime.Now;
        routeCard.SignOff = lastOp.SignOff;
        routeCard.SignOffOn = lastOp.SignOffOn;
    }

    await _myDbContext.SaveChangesAsync();
    Log.Information($"Successfully updated route card {request.RouteNo}");

    return new Response<bool>() { Succeeded = true, Data = true };
}

public async Task<Response<bool>> Handle(UpdateLastOperationCommand request, CancellationToken cancellationToken)
{
    var routeCard = await _myDbContext.RouteCards.FirstOrDefaultAsync(n => n.RouteNo == request.RouteNo);
    var routeOperations =
        await _myDbContext.RouteCardOps.Where(n => n.RouteNo == request.RouteNo).ToListAsync();
    var ordered = routeOperations.OrderBy(n => n.Seq);
    var lastOp = ordered.LastOrDefault();

    if (lastOp == null)
    {
        return new Response<bool>() { Succeeded = true, Data = false, Message = "No operation to update" };
    }

    routeCard.QtyFinished = lastOp.QtyComplete;
    if (routeCard.QtyFinished >= routeCard.BatchQty)
    {
        Log.Information($"RouteCard should be marked as complete");
        routeCard.RouteStatus = "CMP";
        routeCard.StatusDate = DateTime.Now;
        routeCard.CompletedDate = DateTime.Now;
        routeCard.SignOff = lastOp.SignOff;
        routeCard.SignOffOn = lastOp.SignOffOn;
    }

    await _myDbContext.SaveChangesAsync();
    Log.Information($"Successfully updated route card {request.RouteNo}");

    return new Response<bool>() { Succeeded = true, Data = true };
}

Any help would be appreciated.

15 replies

CC#

•Created by kommissar on 2/6/2023 in #help

Serialising and deserialising json derived file

Hello. I have a json derived file (but not quite standard json) that I'd like to serialise and deserialise. Any ideas how to do it easily without writing my own parser? Honestly I wouldn't know where to start.

24 replies

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