如何从多个访问表中获取数据到C＃Windows窗体中？

Question

I am trying to display data from four different database tables using the code below, this method works perfectly for one table but i cant get my head around making it work for multiple, here is the code:

private void Assign_Load(object sender, EventArgs e)
    {
        try
        {
            OleDbConnection conn = new OleDbConnection();
            conn.ConnectionString = ConnectionDetail.Warehouse;
            string sql = "Select * from [Location], [Assign], [Products], [staff]";
            da = new OleDbDataAdapter(sql, conn);
            da.Fill(dt); // filling the database information into databtable

            //Location Table
            DataRow dr = dt.Rows[currentRow]; // counting the rows
            txtLocID.Text = dr["Location ID"].ToString();
            txtAisle.Text = dr["Aisle Code"].ToString(); 
            txtSection.Text = dr["Section"].ToString();
            txtShelf.Text = dr["Shelf"].ToString();
            txtLocation.Text = dr["Location"].ToString();
            txtLength.Text = dr["Length"].ToString();
            txtWidth.Text = dr["Width"].ToString();
            lstSize.Text = dr["Size Description"].ToString();

            //Product Table
            txtSKU.Text = dr["SKU"].ToString();
            txtDes.Text = dr["Description"].ToString(); 
            listHaz.Text = dr["Hazardous"].ToString();
            listLiq.Text = dr["Liquid"].ToString();
            txtQuan.Text = dr["Quantity"].ToString();
            txtWeig.Text = dr["Weight"].ToString();
            lstSize.Text = dr["Size Description"].ToString();

            //Satff Table
            txtID.Text = dr["StaffID"].ToString();

            //Assign Table
            txtAssID.Text = dr["Assign ID"].ToString();
        }
        catch (Exception ex)
        {
            MessageBox.Show(ex.Message);
        }
        {
            OleDbConnection load = new OleDbConnection();
            load.ConnectionString = ConnectionDetail.Warehouse;
            OleDbCommand cmds = new OleDbCommand();
            lbltime.Text = DateTime.Now.ToString("yyyy MMM ddd HH:mm");
            try
            {
                load.Open();
                cmds = new OleDbCommand();
                cmds.CommandText = "SELECT * FROM [Location], [Assign], [Products], [staff];";
                cmds.Connection = load;
                dr = cmds.ExecuteReader();   


            }
            catch (Exception err)
            {
                //Any database errors jump here and output error message
                MessageBox.Show("A database error has occurred: " + Environment.NewLine + err.Message);
            }
            finally
            {
               // btnNext_Click(sender, e);
                txtLocID.Visible = false;
            }
        }
    }

Answer 1

The best answer, is to update your SQL statement to use a JOIN statement. Assuming your data / tables are somehow related.

Else, the other way to do it, is to create separate functions to populate each set of Text items separately.

Looking at your code, I'm betting you should consider "binding".

Answer 2

Figured it out, this works just as well as all your suggestions, thanks for everyone's help anyway.

    OleDbConnection Cons = new OleDbConnection(); // new connection 
    OleDbDataReader dr;
    int currentRow = 0;

    //Location
    DataTable dt = new DataTable();
    OleDbDataAdapter da;

    //Product
    DataTable dt1 = new DataTable();
    OleDbDataAdapter da1;

    //staff
    DataTable dt2 = new DataTable();
    OleDbDataAdapter da2;

    //Assign
    DataTable dt3 = new DataTable();
    OleDbDataAdapter da3;

    private void Assign_Load(object sender, EventArgs e)
    {
        try
        {
            OleDbConnection conn = new OleDbConnection();
            conn.ConnectionString = ConnectionDetail.Warehouse;
            string sql = "Select * from Location";
            da = new OleDbDataAdapter(sql, conn);
            da.Fill(dt); // filling the database information into databtable

            //Location Table
            DataRow dr = dt.Rows[currentRow]; // counting the rows
            txtLocID.Text = dr["Location ID"].ToString();
            txtAisle.Text = dr["Aisle Code"].ToString(); 
            txtSection.Text = dr["Section"].ToString();
            txtShelf.Text = dr["Shelf"].ToString();
            txtLocation.Text = dr["Location"].ToString();
            txtLength.Text = dr["Length"].ToString();
            txtWidth.Text = dr["Width"].ToString();
            lstSize.Text = dr["Size Description"].ToString();

            //Product Table
            OleDbConnection conn1 = new OleDbConnection();
            conn1.ConnectionString = ConnectionDetail.Warehouse;
            string sql1 = "Select * from Products";
            da1 = new OleDbDataAdapter(sql1, conn1);
            da1.Fill(dt1); // filling the database information into databtable

            DataRow dr1 = dt1.Rows[currentRow]; // counting the rows
            txtSKU.Text = dr1["SKU"].ToString();
            txtDes.Text = dr1["Description"].ToString(); 
            listHaz.Text = dr1["Hazardous"].ToString();
            listLiq.Text = dr1["Liquid"].ToString();
            txtQuan.Text = dr1["Quantity"].ToString();
            txtWeig.Text = dr1["Weight"].ToString();
            lstSize1.Text = dr1["Size Description"].ToString();

            //Staff Table
            OleDbConnection conn2 = new OleDbConnection();
            conn2.ConnectionString = ConnectionDetail.Warehouse;
            string sql2 = "Select * from Staff";
            da2 = new OleDbDataAdapter(sql2, conn2);
            da2.Fill(dt2); // filling the database information into databtable

            DataRow dr2 = dt2.Rows[currentRow]; // counting the rows
            txtID.Text = dr2["StaffID"].ToString();

            //Assign Table
            OleDbConnection conn3 = new OleDbConnection();
            conn3.ConnectionString = ConnectionDetail.Warehouse;
            string sql3 = "Select * from Assign";
            da3 = new OleDbDataAdapter(sql3, conn3);
            da3.Fill(dt3); // filling the database information into databtable

            DataRow dr3 = dt3.Rows[currentRow]; // counting the rows
            txtAssID.Text = dr3["Assign ID"].ToString();
        }
        catch (Exception ex)
        {
            MessageBox.Show(ex.Message);
        }
        {
            OleDbConnection load = new OleDbConnection();
            load.ConnectionString = ConnectionDetail.Warehouse;
            OleDbCommand cmds = new OleDbCommand();
            lbltime.Text = DateTime.Now.ToString("yyyy MMM ddd HH:mm");
            try
            {
                load.Open();
                cmds = new OleDbCommand();
                cmds.CommandText = "SELECT * FROM Location;";
                cmds.CommandText = "SELECT * FROM Products;";
                cmds.CommandText = "SELECT * FROM Staff;";
                cmds.CommandText = "SELECT * FROM Assign;";
                cmds.Connection = load;
                dr = cmds.ExecuteReader();   


            }
            catch (Exception err)
            {
                //Any database errors jump here and output error message
                MessageBox.Show("A database error has occurred: " + Environment.NewLine + err.Message);
            }
            finally
            {
               // btnNext_Click(sender, e);
                txtLocID.Visible = false;
            }
        }
    }