loopback hasMany 通过给出空数组答案

【问题标题】：loopback hasMany through gives empty arrayloopback hasMany 通过给出空数组
【发布时间】：2018-07-03 08:11:34
【问题描述】：

我有以下定义的模型：

学院

{
  "name": "academy",
  "base": "PersistedModel",
  "idInjection": true,
  "options": {
    "validateUpsert": true
  },
  "properties": {
    "id": {
      "type": "number",
      "required": true
    },
    "name": {
      "type": "string",
      "required": true
    },
    "created": {
      "type": "date"
    },
    "updated": {
      "type": "date"
    },
    "academy_version_id": {
      "type": "number",
      "required": true
    },
    "description": {
      "type": "string"
    }
  },
  "validations": [],
  "relations": {
    "versions": {
      "type": "hasMany",
      "model": "academy_version",
      "foreignKey": "academy_id",
      "through": "academy_has_versions"
    }
  },
  "acls": [],
  "methods": {}
}

academy_version

        {
      "name": "academy_version",
      "base": "PersistedModel",
      "idInjection": true,
      "options": {
        "validateUpsert": true
      },
      "properties": {
        "id": {
          "type": "number",
          "required": true
        },
        "name": {
          "type": "string",
          "required": true
        },
        "created": {
          "type": "date"
        },
        "updated": {
          "type": "date"
        }
      },
      "validations": [],
      "relations": {
        "academies": {
          "type": "hasMany",
          "model": "academy",
          "foreignKey": "academy_version_id",
          "through": "academy_has_versions"
        }
      },
      "acls": [],
      "methods": {}
    }

academy_has_versions

{
  "name": "academy_has_versions",
  "base": "PersistedModel",
  "idInjection": true,
  "options": {
    "validateUpsert": true
  },
  "properties": {
    "id": {
      "type": "number",
      "required": true
    },
    "academy_id": {
      "type": "number",
      "required": true
    },
    "academy_version_id": {
      "type": "number"
    }
  },
  "validations": [],
  "relations": {
    "academy": {
      "type": "belongsTo",
      "model": "academy",
      "foreignKey": "academy_id"
    },
    "academy_version": {
      "type": "belongsTo",
      "model": "academy_version",
      "foreignKey": "academy_version_id"
    }
  },
  "acls": [],
  "methods": {}
}

现在你可以看到我的academy 模型有一个hasMany 到academy_has_versions

当我尝试请求这个时，我得到以下结果：

如您所见，我得到一个空数组（版本）

这是不正确的，因为我的数据库如下所示：

academy_has_versions

academy_version

那么谁能告诉我我做错了什么？

【问题讨论】：

标签： loopbackjs loopback

【解决方案1】：

我找不到错误，但我建议你试试这个：

从所有模型中删除“id”属性，因为 idInjection 设置为 true。
移除外键对应的属性。
从学院模型中删除 academy_version_id 属性，因为在关系中没有意义。

学院

{
  "name": "academy",
  "base": "PersistedModel",
  "idInjection": true,
  "options": {
    "validateUpsert": true
  },
  "properties": {
    "name": {
      "type": "string",
      "required": true
    },
    "created": {
      "type": "date"
    },
    "updated": {
      "type": "date"
    },
    "description": {
      "type": "string"
    }
  },
  "validations": [],
  "relations": {
    "versions": {
      "type": "hasMany",
      "model": "academy_version",
      "foreignKey": "academy_id",
      "through": "academy_has_versions"
    }
  },
  "acls": [],
  "methods": {}
}

academy_version

{
      "name": "academy_version",
      "base": "PersistedModel",
      "idInjection": true,
      "options": {
        "validateUpsert": true
      },
      "properties": {
        "name": {
          "type": "string",
          "required": true
        },
        "created": {
          "type": "date"
        },
        "updated": {
          "type": "date"
        }
      },
      "validations": [],
      "relations": {
        "academies": {
          "type": "hasMany",
          "model": "academy",
          "foreignKey": "academy_version_id",
          "through": "academy_has_versions"
        }
      },
      "acls": [],
      "methods": {}
    }

academy_has_versions

{
  "name": "academy_has_versions",
  "base": "PersistedModel",
  "idInjection": true,
  "options": {
    "validateUpsert": true
  },
  "properties": {},
  "validations": [],
  "relations": {
    "academy": {
      "type": "belongsTo",
      "model": "academy",
      "foreignKey": "academy_id"
    },
    "academy_version": {
      "type": "belongsTo",
      "model": "academy_version",
      "foreignKey": "academy_version_id"
    }
  },
  "acls": [],
  "methods": {}
}

【讨论】：