query: function(queryObj) {                 return new Promise(function(resolve, reject) {                     request({                         url: obj.url,                         method: 'POST',                         json: true,                         body: {                             query: queryObj.query,                             variables: queryObj.variables                         },                         headers: queryObj.header || header,                         timeout: 5000                     }).then(function (res) {                         //resolve(res)                         console.log(timeout)                         console.log('进入结果判断')                         console.log(res)                         responseHandler(resolve, reject, res,obj.errorHandler)                       }).catch(function (err) {                         console.log('请求失败')                         reject(err)                       });                 });             },

    db.collection('RaidHistory').get({       success:function(res){         console.log(res.data.length)         for(var i=0;i<res.data.length;i++){           //console.log(i)           if(res.data[i].RaidID == ""){             for(var j=0;j<s.length;j++){               if(res.data[i].RaidTitle == s[j].title){                 console.log(res.data[i].RaidTitle,s[j].id)                 var id = s[j].id                 db.collection('RaidHistory').doc(res.data[i]._id).update({                   data:{                     RaidID:id                   }                })             }           }         }        }      }     })   },

请问下 数据库插入数据时怎么样判断是否数据重复？以某个字段为判断值,已经有了就不插入

db.collection('RaidHistory').where({           RaidID:id         }).get({         }).then(res => {           console.log(res.data.length)       if (res.data.length == 0){         db.collection('RaidHistory').add({           data:{             RaidID:result[i].RaidID,             Brand:result[i].Brand,             Leader:result[i].Leader,             Time:result[i].Time,             AllMoney:result[i].AllMoney,           }         })       }      }) 报错:reason: TypeError: Cannot read property 'RaidID' of undefined