Operation gives incorrect result

Question

User-523931540 posted

Hello there
I'm new to the site and I need your help on a topic. Thanks in advance for your help.

I do not know english, I use to google translate, I apologize if there is a translation error.

Operation gives incorrect result, what is the truth?

Could you help me.

I want to do

entering (g) - leaving (c) = remaining

Could you give me a code sample. Please

my table (sql express)

asp.net  (remainingPage.aspx.cs)

 if (!this.IsPostBack)
            {
                SqlDataSource SqlDataSource1 = new SqlDataSource();
                SqlDataSource1.ID = "SqlDataSource1";
                this.Page.Controls.Add(SqlDataSource1);
                SqlDataSource1.ConnectionString = System.Configuration.ConfigurationManager.ConnectionStrings["connect"].ConnectionString;
                SqlDataSource1.SelectCommand = "select s1.marka,s1.renkkodu,s1.renkadi, " +
                    "SUM(case when s1.yontem = 'g' then s1.kilo else 0 end) - SUM(case when s1.yontem = 'c' then s1.kilo else 0 end) as kilo" +
                    " from byh_boya_kalan_tbl s1" +
                    " group by s1.marka,s1.renkkodu,s1.renkadi order by s1.renkadi";
                GridView1.DataSource = SqlDataSource1;
                GridView1.DataBind();
            }