PostgreSQL模型和MongoDB之间的环回有很多漏洞，导致GET结果为空（RESTAPI）

我试图在PostgreSQL模型（

Customer

，

Purchase

）和MongoDB模型（

Product

）之间建立一个

HasManyThrough

）。我按照中的指南，通过引导脚本添加了一些数据（我在PostgreSQL中检查了记录是否正确填充）

问题是每当我尝试使用

/Customers/{id}/products

获取模型时，总是得到空结果（没有错误）。奇怪的是，countapi

/Customers/{id}/products/count

和

/Customers/{id}/products/{fk}

工作得非常好

有没有人能帮我指出问题所在或建议调试问题的方法

以下是我的模型定义：

model config.json

{
  ...
  "User": {
    "dataSource": "postgresDS",
    "public": false
  },
  "Product": {
    "dataSource": "mongoDS",
    "public": true
  },
  "Customer": {
    "dataSource": "postgresDS",
    "public": true
  },
  "Purchase": {
    "dataSource": "postgresDS",
    "public": false
  },
  ...
}

{
  "name": "Customer",
  "base": "User",
  "strict": true,
  "idInjection": true,
  "options": {
    "validateUpsert": true
  },
  "properties": {
    ...
  },
  "validations": [],
  "relations": {
    "products": {
      "type": "hasMany",
      "model": "Product",
      "foreignKey": "customerId",
      "through": "Purchase",
      "keyThrough": "productId"
    }
  },
  ...

{
  "name": "Purchase",
  "base": "PersistedModel",
  "idInjection": true,
  "options": {
    "validateUpsert": true
  },
  "properties": {
    ...
  },
  "relations": {
    "customer": {
      "type": "belongsTo",
      "model": "Customer",
      "foreignKey": "customerId"
    },
    "product": {
      "type": "belongsTo",
      "model": "Product",
      "foreignKey": "productId"
    }
  },
  ...
}

{
  "name": "Product",
  "base": "PersistedModel",
  "idInjection": true,
  ...
  "properties": {
    ...
  },
  "relations": {
    "customers": {
      "type": "hasMany",
      "model": "Customer",
      "foreignKey": "productId",
      "through": "Purchase",
      "keyThrough": "customerId"
    }
  },
  ...
}

{
    "name": "Product",
    "base": "PersistedModel",
    "idInjection": true,
    "options": {
        "validateUpsert": true
    },
    "properties": {
        "id": {
            "type": "string",
            "id": true,
            "mongodb": {
                "field": "_id"
            }
        },
        ...
    },
    "relations": {
        "customers": {
            "type": "hasMany",
            "model": "Customer",
            "foreignKey": "productId",
            "through": "Purchase",
            "keyThrough": "customerId"
        }
    },
}

customer.json

{
  ...
  "User": {
    "dataSource": "postgresDS",
    "public": false
  },
  "Product": {
    "dataSource": "mongoDS",
    "public": true
  },
  "Customer": {
    "dataSource": "postgresDS",
    "public": true
  },
  "Purchase": {
    "dataSource": "postgresDS",
    "public": false
  },
  ...
}

{
  "name": "Customer",
  "base": "User",
  "strict": true,
  "idInjection": true,
  "options": {
    "validateUpsert": true
  },
  "properties": {
    ...
  },
  "validations": [],
  "relations": {
    "products": {
      "type": "hasMany",
      "model": "Product",
      "foreignKey": "customerId",
      "through": "Purchase",
      "keyThrough": "productId"
    }
  },
  ...

{
  "name": "Purchase",
  "base": "PersistedModel",
  "idInjection": true,
  "options": {
    "validateUpsert": true
  },
  "properties": {
    ...
  },
  "relations": {
    "customer": {
      "type": "belongsTo",
      "model": "Customer",
      "foreignKey": "customerId"
    },
    "product": {
      "type": "belongsTo",
      "model": "Product",
      "foreignKey": "productId"
    }
  },
  ...
}

{
  "name": "Product",
  "base": "PersistedModel",
  "idInjection": true,
  ...
  "properties": {
    ...
  },
  "relations": {
    "customers": {
      "type": "hasMany",
      "model": "Customer",
      "foreignKey": "productId",
      "through": "Purchase",
      "keyThrough": "customerId"
    }
  },
  ...
}

{
    "name": "Product",
    "base": "PersistedModel",
    "idInjection": true,
    "options": {
        "validateUpsert": true
    },
    "properties": {
        "id": {
            "type": "string",
            "id": true,
            "mongodb": {
                "field": "_id"
            }
        },
        ...
    },
    "relations": {
        "customers": {
            "type": "hasMany",
            "model": "Customer",
            "foreignKey": "productId",
            "through": "Purchase",
            "keyThrough": "customerId"
        }
    },
}

}

purchase.json

{
  ...
  "User": {
    "dataSource": "postgresDS",
    "public": false
  },
  "Product": {
    "dataSource": "mongoDS",
    "public": true
  },
  "Customer": {
    "dataSource": "postgresDS",
    "public": true
  },
  "Purchase": {
    "dataSource": "postgresDS",
    "public": false
  },
  ...
}

{
  "name": "Customer",
  "base": "User",
  "strict": true,
  "idInjection": true,
  "options": {
    "validateUpsert": true
  },
  "properties": {
    ...
  },
  "validations": [],
  "relations": {
    "products": {
      "type": "hasMany",
      "model": "Product",
      "foreignKey": "customerId",
      "through": "Purchase",
      "keyThrough": "productId"
    }
  },
  ...

{
  "name": "Purchase",
  "base": "PersistedModel",
  "idInjection": true,
  "options": {
    "validateUpsert": true
  },
  "properties": {
    ...
  },
  "relations": {
    "customer": {
      "type": "belongsTo",
      "model": "Customer",
      "foreignKey": "customerId"
    },
    "product": {
      "type": "belongsTo",
      "model": "Product",
      "foreignKey": "productId"
    }
  },
  ...
}

{
  "name": "Product",
  "base": "PersistedModel",
  "idInjection": true,
  ...
  "properties": {
    ...
  },
  "relations": {
    "customers": {
      "type": "hasMany",
      "model": "Customer",
      "foreignKey": "productId",
      "through": "Purchase",
      "keyThrough": "customerId"
    }
  },
  ...
}

{
    "name": "Product",
    "base": "PersistedModel",
    "idInjection": true,
    "options": {
        "validateUpsert": true
    },
    "properties": {
        "id": {
            "type": "string",
            "id": true,
            "mongodb": {
                "field": "_id"
            }
        },
        ...
    },
    "relations": {
        "customers": {
            "type": "hasMany",
            "model": "Customer",
            "foreignKey": "productId",
            "through": "Purchase",
            "keyThrough": "customerId"
        }
    },
}

product.json

{
  ...
  "User": {
    "dataSource": "postgresDS",
    "public": false
  },
  "Product": {
    "dataSource": "mongoDS",
    "public": true
  },
  "Customer": {
    "dataSource": "postgresDS",
    "public": true
  },
  "Purchase": {
    "dataSource": "postgresDS",
    "public": false
  },
  ...
}

{
  "name": "Customer",
  "base": "User",
  "strict": true,
  "idInjection": true,
  "options": {
    "validateUpsert": true
  },
  "properties": {
    ...
  },
  "validations": [],
  "relations": {
    "products": {
      "type": "hasMany",
      "model": "Product",
      "foreignKey": "customerId",
      "through": "Purchase",
      "keyThrough": "productId"
    }
  },
  ...

{
  "name": "Purchase",
  "base": "PersistedModel",
  "idInjection": true,
  "options": {
    "validateUpsert": true
  },
  "properties": {
    ...
  },
  "relations": {
    "customer": {
      "type": "belongsTo",
      "model": "Customer",
      "foreignKey": "customerId"
    },
    "product": {
      "type": "belongsTo",
      "model": "Product",
      "foreignKey": "productId"
    }
  },
  ...
}

{
  "name": "Product",
  "base": "PersistedModel",
  "idInjection": true,
  ...
  "properties": {
    ...
  },
  "relations": {
    "customers": {
      "type": "hasMany",
      "model": "Customer",
      "foreignKey": "productId",
      "through": "Purchase",
      "keyThrough": "customerId"
    }
  },
  ...
}

{
    "name": "Product",
    "base": "PersistedModel",
    "idInjection": true,
    "options": {
        "validateUpsert": true
    },
    "properties": {
        "id": {
            "type": "string",
            "id": true,
            "mongodb": {
                "field": "_id"
            }
        },
        ...
    },
    "relations": {
        "customers": {
            "type": "hasMany",
            "model": "Customer",
            "foreignKey": "productId",
            "through": "Purchase",
            "keyThrough": "customerId"
        }
    },
}

更新

我尝试使用

debug=loopback:connector:*节点进行调试。

并在尝试调用

/Customers/{id}/products

时找到以下条目。我认为问题在于MongoDB查询中使用的

[Object]

。但我不知道如何调试它

loopback:connector:mongodb all +3ms Product { where: { id: { inq: [Object] } } }
loopback:connector:mongodb MongoDB: model=Product command=find +1ms [ { _id: { '$in': [Object] } }, [Function] ]

---

您需要在

Purchase

模型中定义

customerId

和

productId

属性

//purchase.json
{
  "name": "Purchase",
  "base": "PersistedModel",
  "idInjection": true,
  "options": {
    "validateUpsert": true
  },
  "properties": {
    ...
    "productId": {
       "type": "object"
    },
    "customerId": {
       "type": "object"
    }
  },
  "relations": {
    "customer": {
      "type": "belongsTo",
      "model": "Customer",
      "foreignKey": "customerId"
    },
    "product": {
      "type": "belongsTo",
      "model": "Product",
      "foreignKey": "productId"
    }
  },
  ...
}

根据特定数据库设置属性类型

更新

另外，

product.json

需要修改

//product.json
{
  "name": "Product",
  "base": "PersistedModel",
  "idInjection": true,
  ...
  "properties": {
    ...
  },
  "relations": {
    "customers": {
      "type": "hasMany",
      "model": "Customer",
      "foreignKey": "productId",
      "through": "Purchase"
    }
  },
  ...
}

---

最后，我将mongodb

\u id

映射到属性

id

，如中所述

product.json

{
  ...
  "User": {
    "dataSource": "postgresDS",
    "public": false
  },
  "Product": {
    "dataSource": "mongoDS",
    "public": true
  },
  "Customer": {
    "dataSource": "postgresDS",
    "public": true
  },
  "Purchase": {
    "dataSource": "postgresDS",
    "public": false
  },
  ...
}

{
  "name": "Customer",
  "base": "User",
  "strict": true,
  "idInjection": true,
  "options": {
    "validateUpsert": true
  },
  "properties": {
    ...
  },
  "validations": [],
  "relations": {
    "products": {
      "type": "hasMany",
      "model": "Product",
      "foreignKey": "customerId",
      "through": "Purchase",
      "keyThrough": "productId"
    }
  },
  ...

{
  "name": "Purchase",
  "base": "PersistedModel",
  "idInjection": true,
  "options": {
    "validateUpsert": true
  },
  "properties": {
    ...
  },
  "relations": {
    "customer": {
      "type": "belongsTo",
      "model": "Customer",
      "foreignKey": "customerId"
    },
    "product": {
      "type": "belongsTo",
      "model": "Product",
      "foreignKey": "productId"
    }
  },
  ...
}

{
  "name": "Product",
  "base": "PersistedModel",
  "idInjection": true,
  ...
  "properties": {
    ...
  },
  "relations": {
    "customers": {
      "type": "hasMany",
      "model": "Customer",
      "foreignKey": "productId",
      "through": "Purchase",
      "keyThrough": "customerId"
    }
  },
  ...
}

{
    "name": "Product",
    "base": "PersistedModel",
    "idInjection": true,
    "options": {
        "validateUpsert": true
    },
    "properties": {
        "id": {
            "type": "string",
            "id": true,
            "mongodb": {
                "field": "_id"
            }
        },
        ...
    },
    "relations": {
        "customers": {
            "type": "hasMany",
            "model": "Customer",
            "foreignKey": "productId",
            "through": "Purchase",
            "keyThrough": "customerId"
        }
    },
}

---

谢谢你的回复！不幸的是，它仍然不起作用。我已经尝试对类型使用

对象

和

字符串

，但结果仍然为空。你有任何有效的例子吗？我已经按照你的建议更新了我的模型定义（也反映在我的问题中），但不幸的是仍然没有working@YohanesGultom我仍然认为

产品

@YohanesGultom

产品

的定义是错误的，定义应该与

客户

相同，但反过来说，我的错误，这是一个打字错误（已修复）。我已经照你的建议做了，但不幸的是还是一样