使用CodeIgniter联接多个表

Question

I'm needing some help with pulling data from multiple tables ( 3 total ). I know there is the JOIN option, but I'm still having some trouble. Not sure if I can JOIN the tables in one query to get my results. I'll try to explain what I'm doing before I post my attempted code...

I'm trying to make an "Inventory Need" section on my site. I've got an INVENTORY_PRODUCTS table where I check to see if the column UNITSINSTOCK is less than the MINLEVEL qty. Pretty simple. But I also need to check and see if that product is "On Order". To do that I need to check my INVENTORY_ORDERS AND INVENTORY_ORDER_DETAILS tables.

The status of the order is in the INVENTORY_ORDERS table ( if it's 1 or NULL ) and then the details for the orders are in INVENTORY_ORDER_DETAILS . So I will need the SUM for that item if it exists.

My HTML table has the following columns: Product #, Min, Max, Stock, On Order and Need .

This is what I'm trying to use:

    function get_inventory_below_need($mfctId) {

    $this->db->select('
        INVENTORY_PRODUCTS.ID, INVENTORY_PRODUCTS.PRODUCTNUMBER, INVENTORY_PRODUCTS.MINLEVEL, INVENTORY_PRODUCTS.MAXLEVEL, INVENTORY_PRODUCTS.UNITSINSTOCK,
        SUM(INVENTORY_ORDER_DETAILS.QUANTITY) AS ORDERQTY
    ');
    $this->db->from('INVENTORY_PRODUCTS');
    $this->db->join('INVENTORY_ORDER_DETAILS', 'INVENTORY_ORDER_DETAILS.PRODUCTID = INVENTORY_PRODUCTS.ID', 'INNER');
    $this->db->join('INVENTORY_ORDERS', 'INVENTORY_ORDERs.ID = INVENTORY_ORDER_DETAILS.ORDERID', 'LEFT');
    $this->db->where('INVENTORY_PRODUCTS.MANUFACTURERID', $mfctId);
    $this->db->where('INVENTORY_ORDERS.STATUS != 9');
    $this->db->where('INVENTORY_PRODUCTS.UNITSINSTOCK < INVENTORY_PRODUCTS.MINLEVEL');
    $this->db->group_by('INVENTORY_PRODUCTS.PRODUCTNUMBER');
    $this->db->order_by("INVENTORY_PRODUCTS.PRODUCTNUMBER", "asc");

    $query = $this->db->get();

    return $query->result();
}

The problem is it's only displaying items that have a stock level below the min level AND are currently being ordered. But I've got some products that are below min level and not being ordered.

Hope all this makes sense!

Answer 1

$query = $this->db->query('enter sql query here');

确定您将必须键入要使用的查询，但是它看起来可能会更好，并且如果您使用的是PHP MyAdmin或使用另一种访问数据库的方法，则可以对其进行测试。