Why linq contains always returning false value when combined with empty and non empty strings?

Question

Details:

In this below code _reportData.DistrictID and reportData.BeneficieryID values are "". But filter condition is not working. My requirement is to get matching values from the table.
Below code is not filtering the data.

Below is the code to retrieve filtered data

    public async Task<IEnumerable<BeneficieryMasterExcelUpload>> GetBeneficieryReports(ReportsDataSearch _reportData)
    {
       

        IEnumerable<BeneficieryMasterExcelUpload> beneficieryList = _appDBContext.BeneficieryMasterExcelUpload;
        try
        {

            var beneficieryList = (from b in _appDBContext.BeneficieryMasterExcelUpload
                                   where b.Financial_Year.Contains(_reportData.FinancialYear)
                                   || b.District.Contains(_reportData.DistrictID) ||
                                   b.Name.Contains(_reportData.BeneficieryID) ||
                                   b.District.Contains(_reportData.DistrictID) ||
                                   b.Taluk.Contains(_reportData.TalukID) ||
                                          b.Village.StartsWith(_reportData.VillageID) ||
                                           b.SchemeName.Contains(_reportData.SchemeMasterID)



                                   select new BeneficieryMasterExcelUpload()
                                   {
                                       BeneficieryID = b.BeneficieryID,
                                       Name = b.Name,
                                       SchemeName = b.SchemeName,
                                       BusinessName = b.BusinessName,
                                       District = b.District,
                                       Taluk = b.Taluk,
                                       Village = b.Village,
                                       Constitunency_num = b.Constitunency_num,
                                       BankName = b.BankName,
                                       Financial_Year = b.Financial_Year,
                                       Religion = b.Religion,

                                   }).ToList();
            return beneficieryList;
        }
        catch (Exception ex)
        {
            return null;
        }

Have you checked the generated SQL? What database are you running this against? — Guru Stron, Jul 27 '23 at 06:17
There are multiple answers how to do that - [here is one for EF 3.x](https://stackoverflow.com/a/61204960/2501279) . — Guru Stron, Jul 27 '23 at 06:30
you can get query with sql profiler .please share your model and example data to test code? — abolfazl sadeghi, Jul 27 '23 at 08:16
try executing raw sql instead like this: https://learn.microsoft.com/en-us/ef/core/querying/sql-queries also make sure you are indexing your database properly, because this query looks very unhealthy. — Emre Bener, Jul 27 '23 at 10:46

score 0 · Answer 1 · answered Jul 27 '23 at 11:25

0

Are you trying to filter the Beneficiery with the BeneficieryID?

I observed that one of the line says b.Name.Contains(_reportData.BeneficieryID). Instead, are you trying to refer to b.Beneficiery.Contains(_reportData.BeneficieryID)?

answered Jul 27 '23 at 11:25

WWW

63
5

Why linq contains always returning false value when combined with empty and non empty strings?

1 Answers1