PHP

Step 2: Adding Varieties to the Panel

To add varieties to the panel, you need two SQL queries in a single script. This next step adds an additional query to find the varieties of a wine, and the consolidated varieties are presented together with the vintage, winery, and wine name.

The second addition to the panel in this step is the calculation and conditional display of results. We introduce a new feature to the panel that calculates the savings in buying a dozen bottles and shows the user the per-bottle saving of buying a case of wine, but only when there is such a saving. We don't deal with the situation where a case costs more than 12 single purchases.

The script showing these two new concepts is in Example 4-10. The script improves on Example 4-9 by removing the first two limitations identified in the last section. The output of Example 4-10 is shown in Figure 4-4.

Figure 4-4. Adding wine varieties and discounts to the panel
figs/wda_0404.gif
Example 4-10. An improved display with varieties and the dozen-bottle discount
<!DOCTYPE HTML PUBLIC
               "-//W3C//DTD HTML 4.0 Transitional//EN"
               "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
  <title>Alexa and Dave's Online Wines</title>
</head>
<body bgcolor="white">
<h1>New Wines</h1>
Here are three top new wines we have in stock
<br><br>
<?php
   include 'db.inc';
   include 'error.inc';
   // Print out the varieties for a wineID
   function showVarieties($connection, $wineID)
   {
      // Find the varieties of the current wine,
      // and order them by id
      $query = "SELECT gv.variety
                FROM grape_variety gv,
                     wine_variety wv, wine w
                WHERE w.wine_id = wv.wine_id
                AND wv.variety_id = gv.variety_id
                AND w.wine_id = $wineID
                ORDER BY wv.id";
      // Run the query
      if (!($result = @ mysql_query($query, $connection)))
         showerror(  );
      // Retrieve the varieties ...
      while ($row = @ mysql_fetch_array($result))
         // ... and print each one
         echo " " . $row["variety"];
   }
   // ---------
   $query = "SELECT wi.winery_name,
                     i.cost,
                     i.case_cost,
                     w.year,
                     w.wine_name,
                     w.description,
                     w.wine_id
             FROM wine w, winery wi, inventory i
             WHERE w.description != \"\"
             AND w.winery_id = wi.winery_id
             AND w.wine_id = i.wine_id
             ORDER BY i.date_added DESC LIMIT 3";
   // Open a connection to the DBMS
   if (!($connection = @ mysql_connect($hostName,
                                       $username,
                                       $password)))
      die("Could not connect to database");
   if (!mysql_select_db($databaseName, $connection))
      showerror(  );
   // Run the query created above on the database through
   // the connection
   if (!($result = @ mysql_query ($query, $connection)))
      showerror(  );
   echo "\n<table border=\"0\">";
   // Process the three new wines
   while ($row = @ mysql_fetch_array($result))
   {
      // Print a heading for the wine
      echo "\n<tr>\n\t<td bgcolor=\"maroon\">" .
           "<b><font color=\"white\">" .
           $row["year"] . " " .
           $row["winery_name"] . " " .
           $row["wine_name"] . " ";
      // Print the varieties for this wine
      showVarieties($connection, $row["wine_id"]);
      echo "</font></b></td>\n</tr>";
      // Print the wine review
      echo "\n<tr>\n\t<td bgcolor=\"silver\">" .
           "<b>Review: </b>" .
           $row["description"] .
           "</td>\n</tr>";
      // Print the pricing information
      echo "\n<tr>\n\t<td bgcolor=\"gray\">" .
           "<b>Our price: </b>" .
           $row["cost"] .
           "(" . $row["case_cost"] . " a dozen)";
      // Calculate the saving for 12 or more bottle
      $dozen_saving = $row["cost"] - ($row["case_cost"]/12);
      // If there's a saving, show what it is
      if ($dozen_saving > 0)
         printf(" Save <b>%.2f</b> per bottle when
                  buying a dozen\n", $dozen_saving);
      echo "</td>\n</tr>";
      // Blank row for presentation
      echo "\n<tr>\n\t<td></td>\n</tr>";
   }
   echo "\n</table>\n";
   if (!mysql_close($connection))
      showerror(  );
?>
</body>
</html>

by BrainBellupdated
Advertisement: