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我有以下查詢始建通過Laravel:爲什麼查詢返回空集合?
$res = Announcement::whereExists(function ($query) {
$query->select(DB::raw(1))
->from('announcement_category')->join('user_category', 'user_category.category_id', '=', 'announcement_category.category_id')
->where('user_category.user_id', '=', 1)
->where('announcement_category.announcement_id', '=', 'announcements.id');
});
dd($res->get());
上面的代碼給我空集:dd($res->get());
。
此查詢的普通的SQL代碼:
select * from `announcements` where exists (select 1 from
`announcement_category` inner join `user_category` on
`user_category`.`category_id` = `announcement_category`.`category_id` where `user_category`.`user_id` = 1
and `announcement_category`.`announcement_id` = announcements.id)
and `announcements`.`deleted_at` is null
如果直接在MySQL執行此,我得到兩個結果行。
但是爲什麼dd($res->get());
迴廊空?
你爲什麼用'DB ::原料(1)'在SELECT子句? – mrabbani
如果使用'*'結果相同 – Darama