Question

string menuRecipe = "SELECT * FROM recipelist WHERE menu_ID = '" + menuID + "'";
MySqlCommand recipeCmd = new MySqlCommand(menuRecipe, db.mycon);
MySqlDataReader recipeDr = recipeCmd.ExecuteReader();
string[] info = new string[8];
while (recipeDr.Read())
{
    info[1] = (recipeDr["recipe_ID"].ToString());
    info[2] = (recipeDr["stock_ID"].ToString());
    info[4] = (recipeDr["recipe_quantity"].ToString());
    string stockName = "SELECT stock_name FROM stocksdb WHERE stock_ID = '" + info[2] + "'";
    cmd = new MySqlCommand(stockName, db.mycon);
    MySqlDataReader nameDr = cmd.ExecuteReader();
    while (nameDr.Read())
    {
        info[3] = (nameDr["stock_name"].ToString());
    }
    this.recipeList.Items.Add(new ListViewItem(new string[] { info[1], info[2], info[3], info[4] }));
}

I primarily want to reduce having to use multiple SQL command strings, though I don’t know how, and how I could segregate them into their respective places since some may get jumbled up.

Answer 1

You can change your query to

SELECT r.*, s.stock_name FROM recipelist r
LEFT OUTER JOIN stocksdb s ON r.stock_ID = s.stock_ID
WHERE menu_ID = @parameter