MonthlyIncome.cs

using System;
using System.Data;
using System.Data.SQLite;
using System.Windows.Forms;

namespace LabadaPOS
{
    public partial class MonthlyIncome : Form
    {
        public MonthlyIncome()
        {
            InitializeComponent();

            string month = DateTime.Now.ToString("MMMM");
            string year = DateTime.Now.ToString("yyyy");
            string day = DateTime.Now.ToString("dd");
            month_txt.Text = month;
            year_txt.Text = year;
            day_txt.Text = day;
        }

        public void sqlite_aggregate(){
            try
            {

                string myConnection = @"Data Source=sales.db;Version=3;";
                SQLiteConnection con = new SQLiteConnection(myConnection, true);
                string query;
                if (day_txt.Text == "---")
                {
                    query = "SELECT SUM(INCOME) FROM  SALES WHERE MONTH=@MONTH AND YEAR=@YEAR;";
                }
                else if (month_txt.Text == "---") {
                    day_txt.Text = "---";
                    query = "SELECT SUM(INCOME) FROM  SALES WHERE YEAR=@YEAR;";
                }
                else
                {
                    query = "SELECT SUM(INCOME) FROM SALES WHERE MONTH=@MONTH AND DAY=@DAY AND YEAR=@YEAR;";
                }

                SQLiteCommand cmd = new SQLiteCommand(query, con);
                cmd.Parameters.AddWithValue("@MONTH", month_txt.Text);
                cmd.Parameters.AddWithValue("@YEAR", year_txt.Text);
                cmd.Parameters.AddWithValue("@DAY", day_txt.Text);
                SQLiteDataAdapter da = new SQLiteDataAdapter(cmd);
                DataTable dt = new DataTable();
                da.Fill(dt);

                con.Open();
                var total = string.Join(", ", dt.Rows[0].ItemArray);
                if (total == "")
                {
                    income_total.Text = "0.00";
                }
                else {
                    income_total.Text = total;
                }
                
                con.Close();

            }


            catch (Exception ex)
            {

                MessageBox.Show(ex.Message);
            }
            
        }
        public void sqlitequery() {

            try
            {

                string myConnection = @"Data Source=sales.db;Version=3;";
                SQLiteConnection con = new SQLiteConnection(myConnection, true);
                string query;


                if (day_txt.Text == "---")
                {
                    query = "SELECT* FROM SALES WHERE MONTH=@MONTH AND YEAR=@YEAR;";
                }
                else if (month_txt.Text == "---")
                {
                    day_txt.Text = "---";
                    query = "SELECT* FROM SALES WHERE YEAR=@YEAR;";
                }
                else
                {
                    query = "SELECT* FROM SALES WHERE MONTH=@MONTH AND DAY=@DAY AND YEAR=@YEAR;";
                }

                SQLiteCommand cmd = new SQLiteCommand(query, con);
                cmd.Parameters.AddWithValue("@MONTH", month_txt.Text);
                cmd.Parameters.AddWithValue("@YEAR", year_txt.Text);
                cmd.Parameters.AddWithValue("@DAY", day_txt.Text);
                SQLiteDataAdapter da = new SQLiteDataAdapter(cmd);
                DataTable dt = new DataTable();
                da.Fill(dt);

                con.Open();
                dgv1.DataSource = dt;
                con.Close();

            }
            catch (Exception ex)
            {

                MessageBox.Show(ex.Message);
            }
            
        }


        private void timer1_Tick(object sender, EventArgs e)
        {
            date_time.Text = DateTime.Now.ToString("dddd , MMM dd yyyy,hh:mm:ss");
        }

        private void month_txt_TextChanged(object sender, EventArgs e)
        {
            sqlitequery();
            sqlite_aggregate();
        }

        private void day_txt_TextChanged(object sender, EventArgs e)
        {
            sqlitequery();
            sqlite_aggregate();
        }

        private void year_txt_TextChanged(object sender, EventArgs e)
        {
            sqlitequery();
            sqlite_aggregate();
        }
    }
}