unicloud联表查询报错Error: 未找到主表与副表之间的关联关系，注意使用临时表联表查询时只会使用过滤后的字段进行联表

//product.schema.json  
{  
    "bsonType": "object",  
    "required": [  

    ],  
    "permission": {  
        "read": true,  
        "create": true,  
        "update": true,  
        "delete": true  
    },  
    "properties": {  
        "_id": {  
            "description": "ID，系统自动生成"  
        },  
        "id": {  
            "bsonType": "int",  
            "title": "自增ID",  
            "description": "自增ID",  
            "minimum": 1  
        },  
        "category_id": {  
            "bsonType": "int",  
            "title": "分类ID",  
            "description": "分类ID",  
            "minimum": 1,  
            "foreignKey": "product_category.id"  
        },  
        "name": {  
            "bsonType": "string",  
            "title": "商品名称",  
            "description": "分类名",  
            "trim": "both",  
            "maxLength": 255  
        },  
        "product_code": {  
            "bsonType": "string",  
            "title": "商品编码",  
            "description": "商品编码",  
            "trim": "both",  
            "maxLength": 255  
        },  
        "product_barcode": {  
            "bsonType": "string",  
            "title": "商品条码",  
            "description": "商品条码",  
            "trim": "both",  
            "maxLength": 255  
        },  
        "price": {  
            "bsonType": "int",  
            "title": "商品价格",  
            "description": "商品价格, 用分做单位",  
            "minimum": 1  
        },  
        "spec": {  
            "bsonType": "string",  
            "title": "商品规格",  
            "description": "商品规格",  
            "trim": "both",  
            "maxLength": 255  
        },  
        "brand": {  
            "bsonType": "string",  
            "title": "商品品牌",  
            "description": "商品品牌",  
            "trim": "both",  
            "maxLength": 255  
        },  
        "main_pic": {  
            "bsonType": "string",  
            "title": "商品主图",  
            "description": "商品主图",  
            "trim": "both",  
            "maxLength": 10000  
        },  
        "create_time": {  
            "bsonType": "string",  
            "title": "创建时间",  
            "description": "创建时间",  
            "trim": "both",  
            "maxLength": 255  
        },  
        "update_time": {  
            "bsonType": "string",  
            "title": "更新时间",  
            "description": "更新时间",  
            "trim": "both",  
            "maxLength": 255  
        }  
    }  
}  
//product_category.schema.json  
{  
    "bsonType": "object",  
    "required": [  

    ],  
    "permission": {  
        "read": true,  
        "create": true,  
        "update": true,  
        "delete": true  
    },  
    "properties": {  
        "_id": {  
            "description": "ID，系统自动生成"  
        },  
        "id": {  
            "bsonType": "int",  
            "title": "自增ID",  
            "description": "自增ID",  
            "minimum": 1,  
            "foreignKey": "product.category_id"  
        },  
        "name": {  
            "bsonType": "string",  
            "title": "分类名",  
            "description": "分类名",  
            "trim": "both",  
            "maxLength": 255  
        },  
        "desc": {  
            "bsonType": "string",  
            "title": "分类描述",  
            "description": "分类描述",  
            "trim": "both",  
            "maxLength": 255  
        },  
        "create_time": {  
            "bsonType": "string",  
            "title": "创建时间",  
            "description": "创建时间",  
            "trim": "both",  
            "maxLength": 255  
        },  
        "update_time": {  
            "bsonType": "string",  
            "title": "更新时间",  
            "description": "更新时间",  
            "trim": "both",  
            "maxLength": 255  
        }  
    }  
}

弄了好久一直报这个错误Error: 未找到主表与副表之间的关联关系，注意使用临时表联表查询时只会使用过滤后的字段进行联表，想问下是哪里的问题请教下，谢谢