我想做一個子類別的類別,它顯示子類別中的最新主題。顯示子類別的最新主題SQL
但是,在數據庫設置中似乎有些問題。
查詢:
$stmt = $conn->prepare("SELECT *
FROM categories
LEFT JOIN subs ON subs.category_id = categories.id
LEFT JOIN threads ON subs.category_id = threads.subcategory_id
WHERE threads.lastdate = 5 AND categories.id = subs.category_id AND subs.category_id = threads.subcategory_id AND
threads.lastdate = threads.lastdate
GROUP BY threads.lastdate, categories.id ASC")
數據庫:
CREATE TABLE `threads` (
`id` int(11) unsigned NOT NULL AUTO_INCREMENT,
`subcategory_id` int(11) NOT NULL,
`title2` varchar(255) NOT NULL DEFAULT '',
`lastdate` int(11) NOT NULL,
`user` varchar(255) NOT NULL DEFAULT '',
PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=3 DEFAULT CHARSET=latin1;
替補:
CREATE TABLE `subs` (
`id` int(11) unsigned NOT NULL AUTO_INCREMENT,
`title` varchar(255) DEFAULT NULL,
`category_id` int(60) DEFAULT NULL,
PRIMARY KEY (`id`)
)
ENGINE=InnoDB AUTO_INCREMENT=2 DEFAULT CHARSET=latin1;
分類:
CREATE TABLE `categories` (
`id` int(11) unsigned NOT NULL AUTO_INCREMENT,
`name` varchar(255) DEFAULT NULL,
PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=4 DEFAULT CHARSET=latin1;
希望有人讓我走出火。
TJ
你什麼錯誤?提供更多信息。 – Robin
當我嘗試使用lastdate'5'在數據庫中創建新線程時,它仍然返回空白。我對數據庫結構不熟悉,所以也許有人可以在這裏看看誰擁有它的知識? – user6632515