I'm facing a issue when trying to search my page when trying to filter from 5 parameters.

If the parameters is null then I would want to ignore that search and only return results if there is a value in the parameters.

At the moment i used separate parameters but i need something that caters for all 5 and if it has 2 out of 4 values then it should return based on the filter.:

                if (name != null)
                {
                    report = report.Where(asd => asd.name == name).OrderBy(x => x.Id).ToList();
                }
                else if (Id != null)
                {
                    report = report.Where(x => x.Id == Id).OrderBy(x => x.Id).ToList();
                }

So this works with only 1 in mind, how would i join all 4 together so it works together.

This is my full code:

        [HttpGet]
        public ActionResult Get(string Id = null, string name = null, string status = null, string startDate = null, string endDate = null)
        {
            List<ReportModel> report = new List<ReportModel>();
                report = (from data in _context.ReportData
                                   //where data.Id== Id
                                   //&& data.name== name
                                   //&& data.Status == status
                                   //&& data.Date >= Convert.ToDateTime(startDate) && data.Date < Convert.ToDateTime(endDate)
                           select new ReportModel
                           {
                                              Id = data.Id,
                                              Name = data.Plant,
                                              Status = data.Status,
                                              Date = data.Date
                                          }).ToList();

                if (name != null)
                {
                    report = report.Where(asd => asd.name == name).OrderBy(x => x.Id).ToList();
                }
                else if (Id != null)
                {
                    report = report.Where(x => x.Id == Id).OrderBy(x => x.Id).ToList();
                }
                else if (status != null)
                {
                    report = report.Where(x => x.Status == status).OrderBy(x => x.Id).ToList();
                }

                return Ok(report);
            }

Kindly help.

CodePudding user response：

If you care about performance, do not call ToList() early, because it will load whole table into the memory. IQueryable can be combined to produce desired result.

[HttpGet]
public ActionResult Get(string Id = null, string name = null, string status = null, string startDate = null, string endDate = null)
{
    var query = _context.ReportData.AsQueryable();

    if (name != null)
    {
        query = query.Where(asd => asd.name == name);
    }

    if (Id != null)
    {
        query = query.Where(x => x.Id == Id);
    }

    if (status != null)
    {
        query = query.Where(x => x.Status == status);
    }

    query = query.OrderBy(x => x.Id);

    var report = query
        .Select(data => new ReportModel
        {
            Id = data.Id,
            Name = data.Plant,
            Status = data.Status,
            Date = data.Date
        })
        .ToList();

    return Ok(report);
}

CodePudding user response：

Intead of using if condition, you can add directly the condition in the Where clause

if (name != null)
{
    query = query.Where(asd => asd.name == name);
}
// replace by
query = query.Where(asd => asd.name == name || name == null);

when name will be null, the Where condition will always true.