javascript - sequelize - 获取包含模型的 AVG

Question

我有一个类似于 product: { ... ,ratings: [ {rating: 3} ] } 的模式，并且使用 sequalize，我想添加一个属性 product.avg_rating 使用 sequelize。

这是我的代码:

sequelize.models.product.findAll({
    include: [{
       model: sequelize.models.rating,
       as: 'ratings', 
       attributes:  {
        include: ['rating',[sequelize.fn('AVG', 'ratings.rating'), 'avg_rating']]
       },
       group: ['rating.rating'],//also tried ratings.rating, and just rating
    }],
 }).then(products=>{...})

但我一直收到这个错误:

In aggregated query without GROUP BY, expression #1 of SELECT list contains nonaggregated column 'text_rewriter.languageCombination.id'; this is incompatible with sql_mode=only_full_group_by

目标输出:

products: [
   {product: 'product name',
    ...
    ratings: [...],
    avg_rating: 3.7 //THIS AVG IS WHAT I WANT
   },{...}
]

有什么想法我想念的吗？我看过很多例子，但没有一个像我那样使用我发现的 include。

Answer 1

sequelize.models.product.findAll({
include: [{
   model: sequelize.models.rating,
   as: 'ratings', 
   attributes:  ['avg_rating'] //this is column name here
}],
}).then(products=>{...})

这将返回:-

products: [
 {product: 'product name',
 ratings: [...],
 rating : { //here all the attributes you wanted, in this case only 'avg_rating' }
 },
 {...}
]

但是你必须在使用这个之前定义产品表和评级表之间的关系。

表:产品有id，名称

表:评分有id、rating、product_id

在上述情况下，关系将是“rating.belongsTo(product) OR product.hasMay(rating)”