An example of php shopping cart implementation code (session mode)

/**
 * php shopping cart
 * Edit bbs.it-home.org
*/
//Shopping cart session generation code
if(! $session && ! $ scid) {
/*
session is used to distinguish each shopping cart, which is equivalent to the ID number of each cart;
scid is only used to identify a shopping cart ID number, which can be regarded as the name of each cart;
when When both the id and session value of the shopping cart do not exist, a new shopping cart is generated
*/
$session = md5(uniqid(rand()));
/*
Generates a unique shopping cart session number
rand() first generates a random number, uniqid() then generates a unique string based on the random number, and finally performs md5 on the string
*/
SetCookie(scid, $session, time() + 14400);
/*
Set the shopping cart cookie
Variable name: scid (I wonder if there is a $ sign missing here? =》Correction: Add "" to scid)
Variable value: $session
Valid time: Current time + 14400 seconds (within 4 hours)
For detailed usage of the setcookie function, please refer to the PHP manual~
*/
}
class Cart { //Start the shopping cart class
function check_item( $table, $session, $product) {
/*
Check item (table name, session, item)
*/
$query = SELECT * FROM $table WHERE session=' $session' AND product=' $product' ;
/*
Look Check whether the 'product' is in the 'shopping cart' in the 'table'
That is, whether the product has been put into the shopping cart
*/
$result = mysql_query( $query);
if(! $result) {
return 0;
}
/*
Query failed
*/
$numRows = mysql_num_rows( $result);
if( $numRows == 0) {
return 0;
/*
If not found, return 0
*/
} else {
$row = mysql_fetch_object( $result);
return $row->quantity;
/*
If found, return the quantity of the item
It is necessary to explain the mysql_fetch_object function here (also below) Will be used):
[mysql_fetch_object() is similar to mysql_fetch_array(), with one difference - it returns an object instead of an array.】
To get a certain field in a record, you should use "->" instead of using subscripts like an array
*/
}
}
function add_item( $table, $session, $product, $quantity) {
/*
Add new items (table name, session, item, quantity)
*/
$qty = $this->check_item( $table, $session, $product);
/*
Call the above function, First check whether such items have been put into the car
*/
if( $qty == 0) {
$query = INSERT INTO $table (session, product, quantity) VALUES ;
$query .= (' $ session', ' $product', ' $quantity') ;
mysql_query( $query);
/*If it is not in the car, add the item to the car*/
} else {
$quantity += $qty; //If there is, increase the quantity on the original basis
$query = UPDATE $table SET quantity=' $quantity' WHERE session=' $session' AND ;
$query .= product=' $product' ;
mysql_query( $query);
/*
And modify the database
*/
}
}
function delete_item( $table, $session, $product) {
/*
Delete item (table name, session, item)
*/
 $query = DELETE FROM $table WHERE session=' $session' AND product=' $product' ;
mysql_query( $query);
/*
Delete this type of item in the php shopping cart
*/
}
function modify_quantity ($table, $session, $product, $quantity) {
/*
Modify item quantity (table name, session, item, quantity)
*/
$query = UPDATE $table SET quantity=' $quantity' WHERE session =' $session' ;
$query .= AND product=' $product' ;
mysql_query( $query);
/*
Modify the item quantity to the value in the parameter
*/
}
function clear_cart( $ table, $session) {
/*
Clear the shopping cart (nothing to say)
*/
$query = DELETE FROM $table WHERE session=' $session' ;
mysql_query( $query);
}
function cart_total( $ table, $session) {
/*
Total price of items in the car
*/
$query = SELECT * FROM $table WHERE session=' $session' ;
$result = mysql_query( $query);
/*
First Take out all the items in the car
*/
if(mysql_num_rows( $result) > 0) {
while( $row = mysql_fetch_object( $result)) {
/*
If the number of items > 0, then judge one by one Price and calculate
*/
$query = SELECT price FROM inventory WHERE product=' $row->product' ;
$invResult = mysql_query( $query);
/*
 Find the item from the inventory table The price of
*/
$row_price = mysql_fetch_object( $invResult);
$total += ( $row_price->price * $row->quantity);
/*
Total price+= price of the item * price of the item Quantity
 (Everyone should be able to understand it:) )
*/
}
}
return $total; //Return the total price
}
function display_contents($table, $session) {
/*
Get information about Chezhong Detailed information of all items
*/
$count = 0;
/*
Item quantity count
Note that this variable is not only used to count the number of items, but more importantly, it will be used as a subscript in the return value array , used to distinguish each item!
*/
$query = SELECT * FROM $table WHERE session=' $session' ORDER BY id ;
$result = mysql_query( $query);
/*
First take out all the items in the car
*/
while( $ row = mysql_fetch_object( $result)) {
/*
Fetch detailed information for each item separately
*/
$query = SELECT * FROM inventory WHERE product=' $row->product' ;
$result_inv = mysql_query ( $query);
/*
Find related information about the item from the inventory table
*/
$row_inventory = mysql_fetch_object( $result_inv);
$contents[product][ $count] = $row_inventory-> ;product;
$contents[price][ $count] = $row_inventory->price;
$contents[quantity][ $count] = $row->quantity;
$contents[total][ $count] = ($row_inventory->price * $row->quantity);
$contents[description][$count] = $row_inventory->description;
/*
Put all the details about the item into $contents Array
$contents is a two-dimensional array
The first set of subscripts distinguishes the different information of each item (such as item name, price, quantity, etc.)
The second set of subscripts distinguishes different items (this is the previous The function of the defined $count variable)
*/
$count++; //The number of items plus one (i.e. the next item)
}
$total = $this->cart_total( $table, $session);
$contents [final] = $total;
/*
Call the cart_total function above at the same time, calculate the total price
 and put it into the $contents array
*/
return $contents;
/*
return the array
*/
 }
function num_items( $table, $session) {
/*
Returns the total number of item types (that is, it seems nonsense to count two identical items as one - -!)
*/
$query = SELECT * FROM $table WHERE session=' $session' ;
$result = mysql_query( $query);
$num_rows = mysql_num_rows( $result);
return $num_rows;
/*
Take out all the items in the car and get the ones affected by the operation The number of database rows, that is, the total number of items
*/
}
function quant_items($table, $session) {
/*
returns the total number of all items (that is, two identical items are also counted as two items - -#)
*/
$quant = 0;//Total quantity of items
$query = SELECT * FROM $table WHERE session=' $session' ;
$result = mysql_query( $query);
while( $row = mysql_fetch_object( $ result)) {
/*
Take out each item one by one
*/
$quant += $row->quantity; //Add the quantity of the item to the total
}
return $quant; //Return Total amount
}
}
?>