Integration: MySocialDatabase Queries

Interdisciplinary Web DevelopmentCGS2835

database_queries.php

• Contains many php functions which query the database for information.

• This data is sometimes “returned” with return to where the function was called

• Other times, this data is simply echoed from database_queries.php

CGS2835 WebDev

MySocial database

• What information can we ask about this data?

CGS2835 WebDev

Get data for a user

• We can ask the database columns of information for a particular userID

database_get_username($userID)

CGS2835 WebDev

===== In MODEL database_queries.php =====function database_get_username($userID){ $userID = sanitize_input($userID); $data = mysql_query("SELECT username FROM users WHERE userID='$userID'"); $row = mysql_fetch_array($data); $result = $row['username']; return $result;}

===== “Calling” the function, printing the data on the VIEW (user.php) =====$username = database_get_username($userID);echo $username;

Insert posts for a user

• The VIEW user.php has a form that displays if $userID is the same as the $loggedInUser

• This form collects a post and sends it to the controller post_process.php

Calling database_add_user_post($userID, $message)== In post_process.php (Controller, processing the data)==// Get the message to post$post = $_POST["post"];

// Get the user logged in$userID = get_user_logged_in();

// Insert the new post into the database for that user// call the database_add_user_post function and provide the variables// $userID and $postdatabase_add_user_post($userID, $post);

// Go back to the user's pageheader('Location: user.php?userID=' . $userID);

CGS2835 WebDev

database_add_user_post($userID, $message)

== In database_queries.php (Model inserting the data) ==

function database_add_user_post($userID, $message) {// Sanitize the variables $userID and $message$userID = sanitize_input($userID);$message = sanitize_input($message);// Insert the data (userID, message) into the posts table$q = "INSERT INTO posts (userID, message) VALUES ('$userID', '$message')";mysql_query($q);

}

CGS2835 WebDev

Select posts for a user

• With post data inserted for a user, we can select the post data out to display it.

• This will require a VIEW (echo data) and MODEL (select data)

database_get_user_posts($userID)

===== In VIEW user.php =====$posts = database_get_user_posts($userID);<h2>Posts:</h2><div id = "posts_all"><?php echo($posts); ?></div>

database_get_user_posts($userID)===== In database_queries.php =====// Get all of the posts for a userIDfunction database_get_user_posts($userID){ $userID = sanitize_input($userID); $posts = ""; $q = "SELECT message,timestamp FROM posts WHERE userID='$userID' ORDER BY

timestamp DESC"; $result = mysql_query($q); while($row = mysql_fetch_array($result)) { $message = stripslashes($row['message']); $timestamp = $row['timestamp']; $posts = $posts . $timestamp . ": " . $message . "<br />"; } return $posts;}

Many more queries

• There are many more interactions in the database in database_queries.php

• Later topics: – password hashing, database security.– Designing the layout– Adding functionality