Question

我在Yii2中有很多关系：RecipeUnit - IngredientWeight - Ingredient。在RecipeUnit模型中：

public function getIngredientWeights()
{
    return $this->hasMany(IngredientWeight::className(), ['recipe_unit_id' => 'id']);
}

public function getIngredients()
{
    return $this->hasMany(Ingredient::className(), ['id' => 'ingredient_id'])
                ->via('ingredientWeights');
}

使用以下代码ActiveQuery生成两个SQL而不是一个连接，并且需要很长时间（$model是具有id = 4的RecipeUnit实例）：

$model->getIngredients()->orderBy('sort_order')->limit(1)->one()

SELECT * FROM `dh_ingredient_weight`
    WHERE `recipe_unit_id`=4 (2977 records 57.1 ms)
SELECT * FROM `dh_ingredient`
    WHERE `id` IN ('4', '5', ..., '5536')
    ORDER BY `sort_order` LIMIT 1 (1 record 2.7 ms)

如果我使用hasMany / viaTable代替hasMany / via，结果是一样的：

public function getIngredients()
{
    return $this->hasMany(Ingredient::className(), ['id' => 'ingredient_id'])
                ->viaTable(IngredientWeight::tableName(), ['recipe_unit_id' => 'id']);
}

但是没有hasMany会生成正常的连接，运行得非常快：

public function getIngredients()
{
    return Ingredient::find()->joinWith(['ingredientWeights'])->where([
            '{{%ingredient_weight}}.recipe_unit_id' => $this->id]);
}

SELECT `dh_ingredient`.* FROM `dh_ingredient`
    LEFT JOIN`dh_ingredient_weight`
    ON `dh_ingredient`.`id` = `dh_ingredient_weight`.`ingredient_id`
WHERE `dh_ingredient_weight`.recipe_unit_id=4
ORDER BY `sort_order` LIMIT 1 (1 record 0.2 ms)

问题是，如果关系是在没有hasMany / via的最后一个例子中定义的，是否有任何不利之处？

Yii2 hasMany / via vs. hasMany / viaTable vs. find / joinWith

0 个答案: