Converting PHP Code to C# in Visual Studio Windows Form

[flexluthor]

I have a somewhat okay knowledge in Php but I recently started Visual Studio and I was wondering how would I go about converting my code to Visual Studio. I wanted to create a combo box that will print out the main category then the sub category under it then the items under it and so on until all main categories are finished. I had no idea how to write them on C# so I first created the code in PHP and tried to dissect them.

 

So far my current code in Visual Studio is:

private void Form1_Load(object sender, EventArgs e){sc.Open();//For Main CategorySqlCommand get_maincategory_name = new SqlCommand("SELECT * FROM maincategory", sc);SqlDataReader dr2 = get_maincategory_name.ExecuteReader();while (dr2.Read()){comboBox1.Items.Add(dr2["maincategory_name"].ToString());//For Sub CategorySqlCommand get_subcategory_name = new SqlCommand("SELECT * FROM subcategory WHERE maincategory_id='1'", sc);SqlDataReader dr3 = get_subcategory_name.ExecuteReader();while (dr3.Read()){comboBox1.Items.Add("--" + dr3["subcategory_name"].ToString());//For InventorySqlCommand get_inventory_name = new SqlCommand("SELECT * FROM inventory WHERE subcategory_id='1'", sc);SqlDataReader dr4 = get_inventory_name.ExecuteReader();while (dr4.Read()){comboBox1.Items.Add("----" + dr4["item_name"].ToString());}}}sc.Close();}

My PHP code looks like this:

echo "<select>";// FOR MAIN CATEGORY$maincategory_query = mysqli_query($con,"SELECT * FROM maincategory") or mysqli_error();while($got = mysqli_fetch_assoc($maincategory_query)){$maincategory_id = $got['maincategory_id'];$maincategory_name = $got['maincategory_name'];echo "<option disabled>$maincategory_name</option>";// FOR SUB CATEGORY$subcategory_query = mysqli_query($con,"SELECT * FROM subcategory WHERE maincategory_id='$maincategory_id'") or mysqli_error();while($got = mysqli_fetch_assoc($subcategory_query)){$subcategory_id = $got['subcategory_id'];$subcategory_name = $got['subcategory_name'];echo "<option disabled>--$subcategory_name</option>";// FOR ITEM$item_query = mysqli_query($con,"SELECT * FROM item WHERE subcategory_id='$subcategory_id'") or mysqli_error();while($got = mysqli_fetch_assoc($item_query)){$item_id = $got['item_id'];$item_name = $got['item_name'];echo "<option>----$item_name</option>"; }}}echo "</select>";

The problems I'm having:

1. It's only showing the first main category name and nothing else.
2. I'm currently figuring out how to put dr2["maincategory_id"] (to replace the 1) inside the sql statement under WHERE but I'm having trouble figuring out what's the syntax on how it wouldn't be interpreted as a string.
3. I don't know how to disable(or to make read-only) certain parts of the combo box.

[flexluthor]

Nevermind, solved it. The problem was it was using read multiple times (apparently you could only read one by default) so the solution was just adding a code to allow multiple reads on the connection string of the database.