我有两张表:food(id, name), review(user_id, food_id, rating)。现在我想将食物表与评论表连接起来,并将虚拟列添加到名为 avg_rating 的食物表中,这显然会保留基于评论的食物平均评分值。所以我的想法是做这样的事情:
$food = FoodQuery::create()
->filterById(15) // constant for testing purposes only
->leftJoinWithReview()
->withColumn("AVG(review.rating)", "avg_rating")
->groupBy("review.rating")
->find()
现在在调试器中我看到了这个:
result = {Propel\Runtime\Collection\ObjectCollection} [7]
index = {array} [1]
indexSplHash = {array} [1]
model = "Food"
fullyQualifiedModel = \Food
formatter = {Propel\Runtime\Formatter\ObjectFormatter} [10]
data = {array} [1]
0 = {\Food} [34]
new = false
deleted = false
modifiedColumns = {array} [0]
virtualColumns = {array} [1]
avg_rating = "5.0000"
id = 15
name = "Salát Caesar"
collReviews = {Propel\Runtime\Collection\ObjectCollection} [7]
index = {array} [2]
indexSplHash = {array} [2]
model = "Review"
fullyQualifiedModel = "\Review"
formatter = null
data = {array} [2]
0 = {\Review} [14]
new = false
deleted = false
modifiedColumns = {array} [0]
virtualColumns = {array} [0]
user_id = 1
food_id = 15
rating = 3
aFood = {\Food} [34]
aUser = null
alreadyInSave = false
reviewThumbsUpsScheduledForDeletion = null
1 = {\Review} [14]
new = false
deleted = false
modifiedColumns = {array} [0]
virtualColumns = {array} [0]
user_id = 3
food_id = 15
rating = 5
aFood = {\Food} [34]
aUser = null
alreadyInSave = false
reviewThumbsUpsScheduledForDeletion = null
*Propel\Runtime\Collection\Collection*pluralizer = null
collReviewsPartial = false
alreadyInSave = false
reviewsScheduledForDeletion = null
*Propel\Runtime\Collection\Collecti4
问题是平均评分不正确。在 virtualColumns 中,您可以看到值为“5.0000”的 avg_rating 字段。但是当你看起来稍微低一点时,你实际上可以看到这种食物有 2 条评论,评级为 3 和 5,所以平均值应该是“4.0000”。
问题出在哪里?为什么这不能正常工作?