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hympert

By hympert
in PHP Coding Help

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hympert Newbie

hympert

Posted
Posted

Hi everyone, I'm trying to create a blog for myself and I'm having trouble right of the bat.  I'm a beginner by the way.  I'm trying to code a create new category page and check what information is put in by the user.  It doesn't work somehow.  Here're my code.

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN"
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">

<html xmlns="http://www.w3.org/1999/xhtml">
<head>
    <title>Welcome to my blog</title>
    <link href="css/style.css" type="text/css" rel="stylesheet" />
</head>

<body>
<?php 
    require("config.php");
?>
<div id="main">

<h1>Hympert's blog</h1>

    <div id="left">
    
        <div id="categories">
        
            <h3>Categories:</h3>
            <select>
                <option selected="selected"></option>
                <?php 
                //dropdown menu to select a category
                    $categories = mysql_query("SELECT * FROM categories ORDER BY name ASC");
                    while($category = mysql_fetch_array($categories)){
                        echo "<option>" . $category['name'] . "</option>";
                    }
                ?>
            </select>
            <br /><br />
            <form method="get">
            <input name="new_cat" type="submit" value="Create new category" /><br /><br />
            </form>
            <?php 
                $submit = $_GET['new_cat'];
                if(isset($submit)){
            ?>
            <!-- create category form -->
                <form method="get" action="">
                Category name:<input name="cat_name" type="text" value="" /><br /><br />
                <input name="submit" type="submit" value="Create" /><br />
                </form>
            <?php    
                }
                
             $cat_name = $_GET['cat_name'];
            //check category name to see if it is valid or not
            //check the length, existed, blank of input category's nname
                
                
            
            switch ($cat_name){
                case trim($cat_name) == "":
                echo "Please input a category name.";
                break;
                
                case strlen($cat_name) > 50:
                echo "The length of a category name cannot exceed 50 characters.";
                break;
                
                case $r = mysql_query("SELECT name FROM categories"):
                    while($result = mysql_fetch_array($r)){
                        $cat_name = $result;
                    }
                echo "Category name is already exist.";
                break;
                
                default:
                mysql_query("INSERT INTO categories (name) VALUES ({$cat_name})");
                
            }
            
            
            function create_cat_form(){
                echo "<form method=\"get\">
                Category name:<input name=\"cat_name\" type=\"text\"/><br /><br />
                <input name=\"submit\" type=\"submit\" value=\"Create\" /><br />
                </form>";
            }
            ?>
            
            
        </div><!-- end div #categories -->
        
        <div id="posts">
            Posts
        </div><!-- end div #posts -->
        
    </div><!-- end div #left -->
    
    <div id="contents">
        Recently posted
    </div><!-- end div #contents -->


</div><!-- end div #main -->

</body>
</html>


<?php 
//database configuartion

$db_host = "localhost";
$db_user = "root";
$db_pass = "hoanghiepp";
$db_name = "blog";

//database connection

$connect = mysql_connect($db_host, $db_user, $db_pass) or die("Cannot connect to the server");
$select_db = mysql_select_db($db_name) or die("Cannot connect to the database");

?>

The CSS page

/*reset the window format */
* {margin: 0; padding: 0;}

body {
    background-color: azure;
}

h1 {
    text-align: center;  
    margin-top: 50px; 
    padding: 50px;
    font-size: 50px;
    color: violet;
}

/* style for the main div */
#main {
    width: 800px;
    height: 700px;
    background-color: aqua;
    margin: auto;
}

/* style for left div */ 
#left {
    width: 250px;
    height: auto;
    float: left;
    margin-right: 50px;
    background-color: yellow;
}

/* style for categories div */
#categories {
    width: 250px;
    height: auto;
    margin-bottom: 50px;
}

/* style for posts div */
#posts {
    width: 250px;
    height: auto;
    background-color: antiquewhite;
    margin-top: 50px;
}

/* style for contents div */
#contents {
    width: 500px;
    height: auto;
    background-color: beige;
    float: right;
}

a {
    text-decoration: none;
}

Hope anyone can tell me the problem with the switch statement.  I use if statement before and it works perfectly fine, but the code seems too long and repeated.  Thank you very much for helping me out.

config.php

index.php

style.css

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onlyican Advanced Member

onlyican

Posted
Posted (edited)

You mis-understand switches

 

Its not as simply as a group of IFs

 

Its like running IF X == Y OR X == Z or X == X

example

 

switch ($current_weather) {
case 'sunny':
echo 'HAPPY, it is sunny';
break;
 
case' rain':
echo 'Another wet day here in the UK';
break;
 
// We can do multiples
case 'snow':
case 'ice':
echo 'Damn it is cold';
break;
 
//finally a catch all
default:
echo 'The weather could be worse but its OK';
}

 

OR the IF way

 

if ($current_weather === 'sunny') {
echo 'HAPPY, it is sunny';
} elseif ($current_weather === 'rain') {
echo 'Another wet day here in the UK';} elseif ($current_weather == 'snow' || $current_weather == 'ice') {echo 'Damn it is cold';} else {echo 'The weather could be worse but its OK';} 
Edited by onlyican
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hympert Newbie

hympert

Posted
  • Author
Posted

Thank you all for your comments,  I thought switch statement can be used in place of if statement to make the code looks nicer and shorter.  So how can I rewrite my code so it works? I change from switch to if-else statement and it works but I can't add new category into database.  Either the category name is already exist or not (also pass through other checks), it always shows "This category name is already exist."  Any thoughts ?

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN"
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">

<html xmlns="http://www.w3.org/1999/xhtml">
<head>
    <title>Welcome to my blog</title>
    <link href="css/style.css" type="text/css" rel="stylesheet" />
</head>

<body>
<?php 
    require("config.php");
?>
<div id="main">

<h1>Hympert's blog</h1>

    <div id="left">
    
        <div id="categories">
        
            <h3>Categories:</h3>
            <select>
                <option selected="selected"></option>
                <?php 
                //dropdown menu to select a category
                    $categories = mysql_query("SELECT * FROM categories ORDER BY name ASC");
                    while($category = mysql_fetch_array($categories)){
                        echo "<option>" . $category['name'] . "</option>";
                    }
                ?>
            </select>
            <br /><br />
            <form method="get">
            <input name="new_cat" type="submit" value="Create new category" /><br /><br />
            </form>
            <?php 
                $submit = $_GET['new_cat'];
                if(isset($submit)){
            ?>
            <!-- create category form -->
                <form method="get" action="">
                Category name:<input name="cat_name" type="text" value="" /><br /><br />
                <input name="submit" type="submit" value="Create" /><br />
                </form>
         
            <?php
                }
                $cat_name = $_GET['cat_name'];
                //check category name to see if it is valid or not
                //check the length, existed, blank of input category's nname     

            if(isset($cat_name)){         
                if(trim($cat_name) == ""){
                    create_cat_form();
                    echo "Please input a category name.";
                    
                }elseif(strlen($cat_name) > 50){
                    create_cat_form();
                    echo "Category name cannot exceed 50 characters.";
                    
                }elseif($cat_name){
                    $r = mysql_query("SELECT name FROM categories");
                        while($result = mysql_fetch_array($r)){
                            $cat_name = $result;
                        }
                    create_cat_form();
                    echo "This category name is already exist.";
                    
                }else{
                    mysql_query("INSERT INTO categories (name) VALUES ({$cat_name})");
                    echo "New category has been added succesfully.";
                }
            }    
            
            function create_cat_form(){
                echo "<form method=\"get\">
                Category name:<input name=\"cat_name\" type=\"text\"/><br /><br />
                <input name=\"submit\" type=\"submit\" value=\"Create\" /><br />
                </form>";
            }
            ?>
            
            
        </div><!-- end div #categories -->
        
        <div id="posts">
            Posts
        </div><!-- end div #posts -->
        
    </div><!-- end div #left -->
    
    <div id="contents">
        Recently posted
    </div><!-- end div #contents -->


</div><!-- end div #main -->

</body>
</html>
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