[英]MySQL double left join, condition OR and group
我有一些問題。 我嘗試統計所有類別和子類別中的文章。
我使用以下查詢:
SELECT
cat.*, COUNT(art.id) AS total
FROM
article_categories cat
LEFT JOIN
article_categories c2 ON (c2.category_parent = cat.category_id)
LEFT JOIN
articles art ON (art.cid = cat.category_id
OR art.cid = c2.category_id)
WHERE
cat.category_parent = 0 AND art.st = 1
AND IF(art.cid IN (2 , 4, 16, 17, 18, 19, 20, 21, 22),
TO_DAYS(CURDATE()) - TO_DAYS(art.date_edit) < 120,
art.cid)
GROUP BY IF(c2.category_parent > 0,
c2.category_parent,
cat.category_id)
ORDER BY cat.category_order ASC
但對於某些類別,總計= 36355
當我使用此查詢時:
SELECT
*
FROM
`articles`
WHERE
st = 1
AND cid IN (2 , 4, 16, 17, 18, 19, 20, 21, 22)
AND IF(cid IN (2 , 4, 16, 17, 18, 19, 20, 21, 22),
TO_DAYS(CURDATE()) - TO_DAYS(date_edit) < 120,
cid)
總計= 7730
我究竟做錯了什么?
我的桌子:
articles:
- id
- cid
- title
- date_add
- date_edit
- st
article_categories
- category_id
- category_name
- category_order
- category_parent
感謝幫助
[編輯]
$sql1 = "SELECT cat.*, COUNT(art.id) AS total FROM article_categories cat LEFT JOIN articles art ON (art.cid = cat.category_id) WHERE cat.category_parent = 0 AND IF(art.cid IN (2 , 4, 16, 17, 18, 19, 20, 21, 22), TO_DAYS(CURDATE()) - TO_DAYS(art.date_edit) < 120, art.cid) GROUP BY art.cid";
$category = array();
foreach ($row as $cat) {
$total = $cat['total'];
$sql2 = "SELECT cat.*, COUNT(art.id) AS total FROM article_categories cat LEFT JOIN articles art ON (art.cid = cat.category_id) WHERE cat.category_parent = ".$cat['category_id']." AND IF(art.cid IN (2 , 4, 16, 17, 18, 19, 20, 21, 22), TO_DAYS(CURDATE()) - TO_DAYS(art.date_edit) < 120, art.cid) GROUP BY art.cid";
foreach ($row2 as $cat2) {
$total += $cat2['total'];
}
$category[] = array('category_id'=> $cat['category_id'], 'total' => $total);
}
我創建了另一個表:article_categories_rel。
article_categories_rel
- child_id
- parent_id
我自己的新查詢:
SELECT
cat.*,
COUNT(art.id) as ilosc
FROM
article_categories cat
LEFT JOIN
article_categories_rel acr
ON
(cat.category_id=acr.parent_id)
LEFT JOIN
articles art
ON (
art.cid = acr.child_id AND
art.st=1 AND
if(art.cid in(2,4,16,17,18,19,20,21,22),
TO_DAYS( curdate( ) ) - TO_DAYS( art.date_edit )<120,
art.cid)
)
WHERE
cat.category_parent=0
GROUP BY
cat.category_id
ORDER BY
cat.category_order ASC;
它有效;)
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