Dan Knight
- 2002.05.14
Yesterday we created an empty database for our Deal of the Day.
Today we'll create a way to easily add and edit data using a Web
browser.
My son Brian <
http://brkn.net/> has been doing a lot with PHP and
MySQL, so I've worked with him on this project. Frankly, he's doing
most of the work and teaching me quite a bit.
Here's the PHP script Brian put together to allow entering new
deals using a Web browser instead of PHP My Admin. We'll display
the script in a mono typeface and comments in our default
proportional font.
- <?php
-
- $db_server = "localhost";
- $db_username = "id";
- $db_password = "password";
- $db_name = "database";
- $connection =
@mysql_connect($db_server,$db_username,$db_password);
- mysql_select_db($db_name,$connection);
-
- echo "<html><head><title>Add
Deal</title></head><body><h1><center>Add
a deal v2.0</center></h1>";
First up is an if/then construct. If you've just launched the
script, the process is not yet true, so the whole first section is
bypassed.
The ! means "if this field is blank," so !$url
means, "if there is no value for $url," then do whatever follows in
curly brackets. The die command stops any following PHP
commands through the end of the page. It's used here to check that
each necessary field is not empty; if a required field is blank,
this script will not write the record to our database.
- if ($process == "true")
- {
- if (!$url) { die("Enter the url.");
}
- if (!$text) { die("Enter your text.");
}
- if (!$short) { die("Enter short text.");
}
- if (!$year) { die("Set a year."); }
- if (!$month) { die("Set a month.");
}
- if (!$day) { die("Set a day."); }
- if (checkdate($month, $day, $year) == 0) {
die("Choose a valid date."); }
We made an interesting discovery when we added the
checkdate function to verify that the date added is a
valid one. According to
PHP.net, the function returns the value true for a valid
date, false for an invalid date. The PHP 4 Bible only says it
ensures validity without telling exactly what kind of result it
returns. But when we tested for false, it didn't work like it was
supposed to.
The Visual book on PHP gave us the clue we needed, indicating
that the checkdate function returns an integer, not a text string.
Testing for zero solved the problem - and I posted a note to
PHP.net to alert others to the error in their online
documentation.
- $sql_date = "$year$month$day";
- mysql_query("INSERT INTO `deals` (`ID`, `URL`,
`text`, `short`, `extra`, `date`) VALUES ('', '$url', '$text',
'$short', '$extra', '$sql_date')") or die(mysql_error());
The above line adds the deal to our database, and the next line
tells us everything has worked.
- echo "<p>Deal added successfully. Would
you like to add another?</p><hr width=75%>";
- $url = stripslashes($url);
- $text = stripslashes($text);
- $short = stripslashes($short);
- $extra = stripslashes($extra);
- }
The stripslashes command removes the backslashes used to
"escape" characters such as quote marks and parentheses within your
field.
Now we come to the actual data entry. We begin by defining
$cur_year as this year and $cur_month as this
month. Since we'll generally be adding deals for this month and
year, this will speed up data entry.
- $cur_year = date(Y);
- $cur_month = date(m);
The next line creates a standard HTML form that we can use in
our browser. $PHP_SELF refers to this script. The
ereg_replace command replaces a double quote with its HTML
equivalent - " - because HTML can't handle quote marks
nested within quote marks.
This whole paragraph of code (I would have gone for easier to
follow formatting, but Brian wrote the program) puts the form on
the page and gives us a place to enter our data. The
maxlength command beeps when you reach a field's maximum
length and prevents you from typing in more characters than
specified.
- echo "<form action=$PHP_SELF method=post><input
type=hidden name=process value=true><p align=center>URL
(Your link will point here) :<br><input type=text name=url
value=\"" . ereg_replace("\"",""",$url) . "\" size=40
maxlength=128><br>Text (This will link to the URL
specified above. Max. 64 characters) :<br><input type=text
name=text size=40 maxlength=64 value=\"" .
ereg_replace("\"",""",$text) . "\"><br>Short link
(This links to the same URL as above. Max. 32 characters)
:<br><input type=text name=short size=40 maxlength=32
value=\"" . ereg_replace("\"",""",$short) .
"\"><br>Extra (Optional. Extra HTML code may be required.)
:<br><input type=text name=extra size=40 maxlength=128
value=\"" . ereg_replace("\"",""",$extra) .
"\"><br><br>Date (2-digit month(01-12), 2-digit day
(01-31), year) :<br><input type=text name=month size=4
maxlength=2 value=\"$cur_month\"> <input type=text name=day
size=4 maxlength=2> <input type=text name=year size=6
maxlength=4 value=\"$cur_year\"><br><input type=submit
name=submit value=Submit></p></form><p
align=center>Duplicate a deal</p><table cellpadding=0
cellspacing=0 bgcolor=#ffffff width=100%>";
The next section of code lists the 20 deals with the latest
scheduled dates of appearance. Deals are sorted in descending order
by data, and you also have the option to duplicated an existing
deal but give it a new date.
- $most_recent = mysql_query("SELECT * FROM deals ORDER BY
date DESC limit 20");
- while ($array_most_recent =
mysql_fetch_array($most_recent))
- {
- echo "<tr$alt_color><td><form
action=$PHP_SELF method=post><input type=hidden name=process
value=true><input type=hidden name=url value=\"" .
ereg_replace("\"",""",$array_most_recent[URL]) .
"\"><input type=hidden name=text value=\"" .
ereg_replace("\"",""",$array_most_recent[text]) .
"\"><input type=hidden name=short value=\"" .
ereg_replace("\"",""",$array_most_recent[short]) .
"\"><input type=hidden name=extra value=\"" .
ereg_replace("\"",""",$array_most_recent[extra]) .
"\"><p>$array_most_recent[text] < <a
href=$array_most_recent[URL]>$array_most_recent[URL]</a>
> (original displays
$array_most_recent[date])<br>Display on (mm/dd/yyyy)
<input type=text name=month size=4 maxlength=2
value=\"$cur_month\"> <input type=text name=day size=4
maxlength=2> <input type=text name=year size=6 maxlength=4
value=\"$cur_year\"><input type=submit name=submit
value=Duplicate></p></form></td></tr>";
- if ($alt_color == "") { $alt_color = "
bgcolor=#eeeeee"; }
- else { $alt_color = ""; }
- }
The $alt_color alternates the background color behind the deals
- one white, one light gray, and so forth. It's a nice touch.
And always be sure to copyright your code. ;-)
- echo "</table><h1><center>©
Brian Knight,
2002</center></h1></body></html>";
-
- ?>
Next time, we'll look at the PHP code
used to display our Deal of the Day.
