uniCloud 云函数修改数据失败（修复方法语法问题）？

   // 业务方法  
   editFunc() {  
                uni.showLoading({  
                    title: '处理中...'  
                })  
                uniCloud.callFunction({  
                    name: 'dna_update',  
                    data: {  
                            _id:this.dataForm.id,  
                            name:this.dataForm.name,  
                            color:this.dataForm.color,  
                            val:this.dataForm.val  
                        }  
                }).then((res) => {  
                    uni.hideLoading()  
                    uni.showModal({  
                        content: `成功`,  
                        showCancel: false  
                    })  
                }).catch((err) => {  
                    uni.hideLoading()  
                    uni.showModal({  
                        content: `修复数据失败，错误信息为：${err.message}`,  
                        showCancel: false  
                    })  
                    console.error(err)  
                })  
            }  

// 云函数  
'use strict';  
const db = uniCloud.database()  
exports.main = async (event, context) => {  
    const collection = db.collection('HVB-DNA')  
    collection.doc('_id').update({  
        data:{  
            name:   event.data.name,  
            color:  event.data.color,  
            val:    event.data.val  
        }  
    }).then(res=>{  
        if (res.updated === 1) {  
            let result = Object.assign({}, {  
                _id: event.data.id  
            }, event)  
            return {  
                status: 0,  
                msg: `集合数据由${JSON.stringify(docList.data[0])}修改为${JSON.stringify(result)}`  
            }  
        } else {  
            return {  
                status: -1,  
                msg:'集合'+table+'内没有数据'  
            }  
        }  
    }).catch(e=>{console.log(msg)});;  
};

异常问题：
12:02:03.326 [云函数:dna_update] 运行日志：
12:02:03.326 Cannot read property 'name' of undefined
12:02:03.326 TypeError: Cannot read property 'name' of undefined
12:02:03.327 at exports.main (/tmp/function/__index.js:7:21)
12:02:03.327 at module.exports (/tmp/function/index.js:94:26)
12:02:03.327 at runUserFunction (/code/index.js:114:181586)
12:02:03.327 at (<anonymous>)
12:02:03.328 at _tickCallback (internal/process/next_tick.js:188:7)