你应该试试这段代码而不是你的代码。

you should try this code instead of your code.

SqlCommand command = new SqlCommand("UPDATE SAPProduction.ProductionData SET Rejection=@Reject,Remark=@Remark Where id = '" + dataGridView1.CurrentRow.Cells["id"].Value.ToString() + "'  ", objConn1);

SqlCommand command = new SqlCommand（UPDATE SAPProduction.ProductionData SET Rejection = @ Reject，Remark = @ Remark where id ='+ dataGridView1.CurrentRow.Cells [id]。Value.ToString（）+'，objConn1）;

SqlCommand command = new SqlCommand("UPDATE SAPProduction.ProductionData SET Rejection=@Reject,Remark=@Remark Where id = '" + dataGridView1.CurrentRow.Cells["id"].Value.ToString() + "' ", objConn1);