Joining results of two independent query - mysql

Question

I have two working queries:
1st returns the product list:
$sql = "
SELECT a.stockID, a.stockCatID, a.stockName, a.stockCode, a.stockCatCode,
CONCAT_WS(' » ', d.stockCatName, c.stockCatName, b.stockCatName) AS stockPath,
a.stockName AS stockTitle, a.stockID AS uniStock
FROM stockcards a
LEFT OUTER JOIN stockcategories b
ON a.stockCatID = b.stockCatID
LEFT OUTER JOIN stockcategories c
ON b.stockParentCat = c.stockCatID
LEFT OUTER JOIN stockcategories d
ON c.stockParentCat = d.stockCatID ";
2nd is basically returns the difference of total received and total sent whic is remaining quantity:
SELECT DISTINCT (COALESCE(o.totalReceived, 0) + COALESCE(p.totalSent, 0)) as RemainingStock
FROM deliverydetails k
INNER JOIN stockcards l ON k.stockID= l.stockID
LEFT JOIN
(
SELECT m.stockID, SUM(m.dQuantity) totalReceived
FROM deliverydetails m
WHERE m.dQuantity > 0
GROUP BY m.stockID
)
o ON k.stockID = o.stockID
LEFT JOIN
(
SELECT n.stockID, SUM(n.dQuantity) totalSent
FROM deliverydetails n
WHERE n.dQuantity < 0
GROUP BY n.stockID
)
p ON k.stockID = p.stockID
I need to add a new column to first query to display remanining quantity. But couldn't succeed to join this two. Thanks for any tip.

Answer 1

As it seems that your 2nd query just sums positive and negative dQuantities for each stockID, and then adds them together, I think this small change to your 1st query is
all that is needed:
SELECT a.stockID, a.stockCatID, a.stockName, a.stockCode, a.stockCatCode,
CONCAT_WS(' » ', d.stockCatName, c.stockCatName, b.stockCatName) AS stockPath,
a.stockName AS stockTitle, a.stockID AS uniStock,
dd.RemainingStock AS RemainingStock
FROM stockcards a
LEFT OUTER JOIN stockcategories b
ON a.stockCatID = b.stockCatID
LEFT OUTER JOIN stockcategories c
ON b.stockParentCat = c.stockCatID
LEFT OUTER JOIN stockcategories d
ON c.stockParentCat = d.stockCatID
LEFT OUTER JOIN
(SELECT stockID, SUM(dQuantity) AS RemainingStock
FROM deliverydetails
GROUP BY stockID) AS dd
ON dd.stockID = a.stockID