我有幾個稱爲海報的項目有日誌。我想在創建這些日誌的日期前訂購海報。 我有一個名爲海報與此代碼模式: class Poster extends Model {
protected $table = 'posters';
public function pos_log_resumenEnviado()
{
return $this->hasMany('App\models\Post
我有MariaDB的10.1.14,很長一段時間我做沒有問題下面的查詢(它tooks約3秒): SELECT
sum(transaction_total) as sum_total,
count(*) as count_all,
transaction_currency
FROM
transactions
WHERE
DATE(transact
我是新來arangoDB與圖形。我只是想知道,建立邊緣還是使用'DOCUMENT()'進行非常簡單的1:1連接(不需要查詢圖形)會更快? LET a = DOCUMENT(@from)
FOR v IN OUTBOUND a
CollectionAHasCollectionB
RETURN MERGE(a,{b:v})
VS LET a = DOCUMENT(@from)
RETURN
假設我有小表(t1)和大表(t2)。我有t2的索引列1和列2。如果我想要INNER JOIN t1和(select * from t2 where column1 = x)那麼即使在內部連接t1(select * from t2 where column1 = x)之後,t2上的索引仍然有用嗎? 如果我的查詢是(select * from t2 where column1 = x)那麼明顯的索引是