主键在副表里面的,clientDB怎么列出列表数据?

数据类:

{  
      "_id": {  
        "_value": "63ce9f6930ee45ddc1424ab8",  
        "yc-payments": [  
          {  
            "_id": "63d12e90819ce8248e9684c1",  
            "pay_date": 1674576000000,  
            "contract_id": "63ce9f6930ee45ddc1424ab8",  
            "amount": 8888,  
            "invoice_amount": null  
          },  
          {  
            "_id": "63d34eabf5cf3a4b662d8ff3",  
            "pay_date": 1674748800000,  
            "contract_id": "63ce9f6930ee45ddc1424ab8",  
            "amount": 123,  
            "invoice_amount": 124  
          }  
        ]  
      },  
      "name": "三期工业污水3#、4#格栅维修合同",  
      "co_organizer": "江苏博尔科环保科技有限公司",  
      "contract_no": "SXW—S—2021—008",  
      "amount": 79680  
    },

读取代码:
let item = data[i]
item.payments=item._id.yc-payments.map({支付日期: pItem.pay_date,支付金额:pItem.amount})

错误
Error in v-on handler: ReferenceError: payments is not defined