Visual Studio C# datagridview to database -

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• what nullreferenceexception, , how fix it? 33 answers

i'm trying save data datagridview database. keep on getting

nullreferenceexception: object reference not set instance of object

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try  {                foreach (datagridviewrow row in datagridview2.rows)     {                     using ( conn = new sqlconnection(constring))         {             using (sqlcommand cmd = new sqlcommand("insert tbl_students_marks values(@student, @t1, @t2, @t3, @t4)", conn))             {                 cmd.parameters.addwithvalue("@student", (row.cells["student number"].value).tostring());                 cmd.parameters.addwithvalue("@t1", row.cells["test 1"].value);                 cmd.parameters.addwithvalue("@t2", row.cells["test 2"].value);                 cmd.parameters.addwithvalue("@t3", row.cells["test 3"].value);                 cmd.parameters.addwithvalue("@t4", row.cells["test 4"].value);                 conn.open();                 cmd.executenonquery();                 conn.close(); 

looks row value empty.

try replace line 9 code:

            var studentnumber = row.cells["student number"].value             if (studentnumber == null || studentnumber dbnull)               continue;             cmd.parameters.addwithvalue("@student", studentnumber.tostring());