is like this. I just came into contact with this project, and then I am not familiar with Linq. After selecting the date of the calendar control in the project, there is no data in the filter, only the date field has no filtering effect, and other fields can be seen. After the Contains method, there is no data. I breakpoint took the conditions in Contains and went to the database to query. The code is as follows:

private static EnumerableRowCollection<DataRow> NewMethod(string seacher, int ttt, string[] newtablename, List<string[]> lstmsg, DataTable ddt, EnumerableRowCollection<DataRow> objmm)
        {
            if (!string.IsNullOrEmpty(seacher) && seacher != "{")
            {
                object jsonobj = JsonConvert.DeserializeObject(seacher);
                JContainer ja = (JContainer)jsonobj;
                JToken jjjj = newtablename[ttt].Equals("tbMygrid") ? ja["tbMygrid"] : ja["tb_" + newtablename[ttt]];
                if (jjjj != null)
                {
                    object objjjj = JsonConvert.DeserializeObject(jjjj.ToString());
                    JArray jaa = (JArray)objjjj;
                    JToken[] j = jaa.AsEnumerable().First().ToArray();
                    foreach (var jitem in j)
                    {
                        string[] aa = jitem.ToString().Split(":");
                        if (aa.Length == 2)
                        {
                            string field = aa[0].Replace("\"", "[|PP|]").Replace("[|PP|]", "").Replace("\"", "[|PP|]").Replace("[|PP|]", "");
                            string fieldValue = aa[1].Replace("\"", "[|PP|]").Replace("[|PP|]", "").Replace("\"", "[|PP|]").Replace("[|PP|]", "");
                            string[] msgobj = new string[] { field.Trim(), fieldValue.Trim() };
                            lstmsg.Add(msgobj);
                            if (ddt.Columns.Contains(field.Trim())) objmm = objmm.Where(m => (Convert.IsDBNull(m[field]) ? "" : m[field].ToString().Trim().Replace("/", "-")).Contains(fieldValue.Trim()));
                        }
                    }
                }

            }
            return objmm;
        }

this is the filtering method, which returns datarow, and then has the following code reference:

//
                    sql = string.Format("Select a.*,ISNULL(b.english,a.fieldcaption) AS english from pps_opmasterlist1detail  A LEFT JOIN  xt_foreign b ON b.chinese=a.fieldcaption where  a.opeid ="{0}" and  a.autoid ={1}  ORDER BY cxcol DESC,cxid ASC ", opeid, item["autoid"]);
                    sql +=Environment.NewLine+ querysql;
                    DataSet dtAll = LfemporderManager.ExecuteDataset(sql);
                    //
                    -sharpregion ""
                    DataTable dtDetail = dtAll.Tables[0];
                    DataTable dtMain = dtAll.Tables[1];
                    var objmm = dtMain.AsEnumerable();
                    List<string[]> lstmsg = new List<string[]>();
                    objmm = NewMethod(another, 0, new string[] { "tbMygrid" }, lstmsg, dtMain, objmm);
                    DataTable newdate = new DataTable();
                    if (objmm.Count() > 0) newdate = objmm.CopyToDataTable();
                    int total = objmm.Count();

newdate this variable will end up with no data, is empty, if I Filter other fields, there will be no data.
the ddate field data of the database is as follows

I really don"t know how to find the problem. I"d like to ask you how to solve it.