MERGE INTO Person AS P
USING (
    SELECT *
    FROM  OPENJSON(@json)
          WITH (id int, firstName nvarchar(50), lastName nvarchar(50),
                age int, dateOfBirth datetime2))

private void label1_Click(object sender, KeyEventArgs e)
       {
           if (wrad1 == 1)
           {
               if (e.KeyCode == Keys.Enter)
               {
                   string wsifrarad;
                   string wimerad;

                   // if (wrad1 == 1)
                   // {
                   wsifrarad = textBox2.Text;
                   //Create a list to store the result
                   List<string>[ ] list = new List<string>[ 3 ];
                   list[ 0 ]=new List<string> ( );
                   string query = "SELECT lozinke.imerad INTO wimerad FROM lozinke WHERE lozinke.imerad =" +
                                  (wsifrarad);
                   MySqlCommand cmd = new MySqlCommand ( query , connection );
                   MySqlDataReader dataReader = cmd.ExecuteReader();
                   while ( dataReader. Read ( ) )
                   {
                       list[0].Add(dataReader["imerad"]+ "");
                   }
                   //close Data Reader
                   dataReader. Close ( );

                   // OpenConnection ( );
                   // string wow = "SELECT `CustomerName` FROM `CustomerInfo`";
                   //MySqlDataAdapter adap = new MySqlDataAdapter(query, connection);
                   //DataTable adapter = new DataTable();
                   // adap.Fill(adapter);
                 //  if ( adapter.Rows.Count == 0)
                 //  {
                  //     MessageBox.Show("Takav operater ne postoji");
                  // }
                  // else
                 //  {
                 //      foreach (DataRow dr in adapter.Rows) ;
                 //  }
                //   if (adapter == input)
                //   {
                //       MessageBox.Show(" operater postoji ");
                 //  }
               }
           }
           else
           {
               MessageBox.Show(" MORATE PRVO DA SE KONEKTUJETE NA SERVER ");
           }
       }

       private bool OpenConnection()
       {
           // citam podatke o serveru iz fileput.txt koja mora biti upisana sa NOTPAD i to sa UTF8 jer unapred ne znam gde je instaliran i moraju da budu \\ pre filePut.txt
           string wput1;
           var fileStream = new FileStream ( @"fileput.txt" , FileMode. Open , FileAccess. Read );
           using ( var streamReader = new StreamReader ( fileStream , Encoding. UTF8 ) )
           {
               wput1=streamReader. ReadToEnd ( );
           }
           //    ovo je kada znam da je server na lokalnoj masini sa programom
           //    server="localhost";
           //    database="lozinke";
           //    userid="root";
           //    password="root";
           //    port="3306";
           //   connectionString=@"server=localhost;port=3306;userid=root;password=root;";
           var connectionString = "";
           connectionString=(wput1);
           connection=new MySqlConnection ( connectionString );
         //  OpenConnection ( );
           try
           {
               System.Diagnostics.Debug.Assert(connection != null, "connection != null");
               connection.Open();
               return true;
           }
           catch (MySqlException ee)
           {
               switch (ee.Number)
               {
                   case 0:
                       MessageBox.Show(" USPESNO STE SE KONEKTOVALI NA SERVER, NASTAVITE SA RADOM ");
                       wrad1 = 1;
                       // return true;
                       break;
                   case 1042:
                       MessageBox.Show(
                       " NE MOGU DA PRONADJEM SERVER / NIJE AKTIVAN SERVER, PODIGNITE SERVER PA PONOVITE KONEKTOVANJE ");
                       break;
               }
               connection.Close();
               return false;
           }
       }