How to display rows in mysql table based on varying external values - php

Question

I hope someone can help with the following... I have multiple product names in a MYSQL database table on one hand and on the other hand I am getting some info such as pricing (excluding product name and some other static info) from xml feeds. The xml feed gives a product code, with which I can match the rows I need in the database because the database includes name of the product but also product code whilst xml doesn't include name of the product.
What I want to do is to fetch the name of the product and some other values from the database and link them with the other info from the xml, so that the end result is that I display the name of the products and the other info on the front-end. There are multiple products from multiple xml's...
If this was single product with a single code, I know I can use the SELECT statement with a where clause, wherein the WHERE clause is the product ID, but because I have multiple products with multiple ID's and I don't need to fetch everything from the database (but only those products displayed/searched for on the front-end), I am a bit stuck and don't know how to do this.
I hope this makes sense. If not, please do let me know.
Thanks in advance.

Answer 1

When you're processing the XML feed, put all the product codes into an array. Then you can construct the SQL query dynamically from this:
$codes_string = implode(', ', $product_codes);
$sql = "SELECT * FROM product_table WHERE product_id IN ($codes_string)";
I'm assuming product IDs are numeric IDs. If they're strings you'll need to put quotes around each of them:
$codes_string = implode("', '", $product_codes);
$sql = "SELECT * FROM product_table WHERE product_id IN ('$codes_string')";

Answer 2

You could likely use an IN query to get the products from the table. Then you'd have to merge them into an object or array of the rows you got via XML.
select * from `mydb`.`myproducts` where product_id in ('key1', 'key2', 'key3');
By your comments across the different answers, if you are looking to build your array of product codes, here's the most viable approach:
$productIds = array();
foreach ($myXmlRecords as $xmlProduct) {
array_push($productIds, $xmlProduct->product_id);
}
$query = 'select * from `mydb`.`myproducts` where product_id in (\'' . implode("', '", $productIds) . '\')';
Taking it a step farther, if you wanted to join the data of the two instead then I'd do the following:
$products = array();
$productIds = array();
foreach ($myXmlRecords as $xmlProduct) {
$p = new stdClass();
$p->product_id = $xmlProduct->product_id;
$p->xmlProp1 = $xmlProduct->prop1;
$p->xmlProp2 = $xmlProduct->prop2; // basically transfer any Xml properties you want to retain to the new $p object
array_push($products, $p);
array_push($productIds, $xmlProduct->product_id);
}
// Now build your query that will grab all matching products you got from Xml
$query = 'select * from `mydb`.`myproducts` where product_id in (\'' . implode("', '", $productIds) . '\')';
// Now match up the results
$results = mysql_query($query);
foreach ($results as $prodRow) {
foreach ($products as $p) {
if ($p->product_id == $prodRow->product_id) {
// These match, now add your db properties to the product
$p->dbProp1 = $prodRow->prop1;
$p->dbProp2 = $prodRow->prop2; // and so on
}
}
}
The end result is an array of products that have the Xml and Db info you want to combine. Before someone corrects me, there is probably a more efficient way than nested foreach statements such as updating the mysql query to use a join against the Xml data and then selecting from both that and your DB. But this is a fast approach that should get you where you need to.
Hope that helps!