Minus data from the program to the database

[fuhanspujisaputra]

How do i minus data from the program to the database?

I have quantity and description in my database. The quantity will be 100, and the description of it will be A.

When i type in my program like this (after run the program): The quantity is 50. and the description of it is A.

The database: The quantity will be 50 (because minus with the database and my program "100 - 50 = 50", and the description still remains same as A.

How do i do that?

Thanks in advance!

Edit:

I already did like this:

private void UpdateDatas()
        {
            int codeValue = 0;
            int index = 0;

            if (firstForm.textBox1.Text == "Seranne")
            {
                string query = "SELECT [Quantity], [Description], [Price] FROM [Seranne] WHERE [Code] IN (";

                OleDbDataReader dReader;
                OleDbConnection conn = new OleDbConnection(connectionString);
                conn.Open();

                if (int.TryParse(this.textBoxCodeContainer[0].Text, out codeValue))
                {
                    query = query + codeValue.ToString();
                }

                for (int i = 1; i < 17; i++)
                {
                    if (int.TryParse(this.textBoxCodeContainer[i].Text, out codeValue))
                    {
                        query = query + "," + codeValue.ToString();
                    }
                }

                query = query + ")";

                OleDbCommand cmd = new OleDbCommand(query, conn);

                cmd.Parameters.Add("Code", System.Data.OleDb.OleDbType.Integer);
                cmd.Parameters.Add("Quantity", System.Data.OleDb.OleDbType.Integer);

                dReader = cmd.ExecuteReader();

                while (dReader.Read())
                {
                    if (textBoxCodeContainer[index].TextLength != 0)
                    {
                        this.textBoxQuantityContainer[index].Value = Convert.ToDecimal(dReader["Quantity"].ToString());
                        this.textBoxDescContainer[index].Text = dReader["Description"].ToString();
                        this.textBoxSubTotalContainer[index].Text = dReader["Price"].ToString();
                    }

                    if (textBoxQuantityContainer[index].Value != 0)
                    {
                        if (textBoxQuantityContainer[index].Value >= Convert.ToDecimal(dReader["Quantity"].ToString()))
                        {
                             decimal newVal = textBoxQuantityContainer[index].Value - Convert.ToDecimal(dReader["Quantity"].ToString());
                             cmd = new OleDbCommand("UPDATE [Seranne] SET [Quantity] ='" + newVal + "' WHERE [Code] IN (");
                        }
                    }

                    index += 1;
                }

                dReader.Close();
                conn.Close();
            }
        }

        private void AddObjects(object sender, EventArgs e, Form theForm)
        {
            if (firstForm.textBox1.Text == "Fuhans")
            {
                textBoxQuantityContainer = new List<NumericUpDown>();
                textBoxCodeContainer = new List<NumericTextBox>();
                textBoxDescContainer = new List<TextBox>();
                textBoxSubTotalContainer = new List<TextBox>();
                textBoxTotalContainer = new List<TextBox>();
                textBoxAllTotalContainer = new TextBox();

                OleDbDataReader dReader;
                OleDbConnection conn = new OleDbConnection(connectionString);
                conn.Open();

                OleDbCommand cmd = new OleDbCommand("SELECT [Code] FROM [Fuhans]", conn);

                dReader = cmd.ExecuteReader();

                AutoCompleteStringCollection codesCollection = new AutoCompleteStringCollection();

                while (dReader.Read())
                {
                    string numString = dReader[0].ToString().PadLeft(4, '0');
                    codesCollection.Add(numString);
                }

                dReader.Close();
                conn.Close();
}

Here is the link of the screenshots:

https://www.dropbox.com/s/i29o9r0wwc4zgu2/324303.png

https://www.dropbox.com/s/x4m43wo5axo1xon/324304.png

"Code" displayed in the screenshot above is refer to the database, and also the "Quantity", whenever i type the code that already have in the database, the remaining box are filled up. But, when i change the "Quantity" from 100 to 50, it is automatically refresh the program to back to 100 again.

Thanks in advance!

[ss125]

The problem is with your code at the line 49

decimal newVal = textBoxQuantityContainer[index].Value - Convert.ToDecimal(dReader["Quantity"].ToString());

In order to do a math function(minus) both the data must be numerical. But while retrieving data from database it will be in string format. so your code failed.

Solution:
you have to convert the data to integer and then perform math operations.

int qty1=Convert.ToInt32(dReader["Quantity"].ToString());
int qty2=Convert.ToInt32(textBoxQuantityContainer[index].Value.ToString());

int final_qty=qt1-qy2;

Now store the final_qty in the database...

Hope this helps you...

Have a happie coding...:D