You want to retrieve data from a database.
Use SELECT to retrieve data from a table based on some criteria. use SELECT * FROM to list all the fields and rows in a table.
SELECT column_name FROM table_name;
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml" xml:lang="EN" lang="EN"> <head> <title>Retrieving Data from a Database</title> <meta Name="Author" Content="Hann So"> </head> <body> <p> <?php if (isset($_POST['submit'])) { process_form(); } else { display_form();// display form for the first time } function display_form() { echo <<<HTML <h2>Retrieving Data from a Database</h2> <form action = "$_SERVER[SCRIPT_NAME]" method="post"> Username: <input type="text" name="username" size="50" value="hann" /> <br /> Password: <input type="password" name="password" size="50" /> <br /> Database name: <input type="text" name="db" size="50" value="hann_db" /> <br /> Table name: <input type="text" name="table" size="50" value="blog_entries" /> <br /> Sort (DESC= descending, ASC=Ascending): <input type="text" name="sort" size="50" value="date_entered DESC" /> <br /> <input type="submit" name="submit" value="Submit" /> </form> HTML; } function process_form() { DEFINE ('DB_HOST', "localhost"); DEFINE ('DB_USER', "$_POST[username]"); DEFINE ('DB_PASSWORD', "$_POST[password]"); DEFINE ('DB_NAME', "$_POST[db]"); DEFINE ('TABLE_NAME', "$_POST[table]"); $sort = stripslashes(trim($_POST[sort])); echo "<p>Opening the connection to the database server.</p>"; if ($link = mysql_connect(DB_HOST, DB_USER, DB_PASSWORD)) { echo "<p>The connection worked. The link is $link</p>"; // select a database if (@mysql_select_db(DB_NAME)) { echo "<P>The database ", DB_NAME, " has been selected.</p>"; } else { die ("<p>Could not select the database because: ". mysql_error(). "</p>"); } // define the query // every column of every row // DESC = descending, ASC= ascending $query = "SELECT * FROM " . TABLE_NAME . " ORDER BY " . "$sort"; // run the query if ($r = @mysql_query($query)) { // retrieve and print every record echo "<h3>The table has the following entries:</h3>"; // mysql_fetch_array fetches a result row as an associative array, // a numeric array, or both while ($row = mysql_fetch_array($r)) { echo "<p>blog_id={$row['blog_id']}<h4>{$row['title']}</h4> {$row['entry']}<br /> <a href=\"example_u.php?id={$row['blog_id']}\">Edit</a> <a href=\"example_d.php?id={$row['blog_id']}\">Delete</a> </p><hr />"; } // close the connection mysql_close($link); } else { die ("<p>Could not retrieve records because: ". mysql_error(). "</p>"); } } else { die ("<p>Could not connect to MySQL because: ". mysql_error(). "</p>"); } echo "<p><a href=\"$_SERVER[SCRIPT_NAME]\">Try again?</a></p>\n"; echo "<p><a href=\"example_i.php\">Insert data?</a></p>\n"; echo "<p><a href=\"example_u.php\">Update data?</a></p>\n"; echo "<p><a href=\"example_d.php\">Delete data?</a></p>\n"; } ?> </p> </body> </html> |