先放几种后端遇到的异常，多数和数据库有关

pymysql.err.InternalError: Packet sequence number wrong - got 102 expected 1
127.0.0.1 - - [09/May/2024 17:49:37] "GET /monitorLastTenList HTTP/1.1" 500 

AttributeError: 'NoneType' object has no attribute 'read'
127.0.0.1 - - [09/May/2024 17:49:37] "GET /alarmTotal HTTP/1.1" 500 -

使用pymysql报错err.ProgrammingError: execute() first

异常代码如下：

onMounted(() => {
  // getList();
  // getPeopleTotal().then(({ data }) =>{
  //   // 更新人数总量
  //   peopleTotal.value = data.total;
  // })
  getPeopleTotal().then(response => {
    // 打印请求返回的数据
    console.log('Total people count:', response.data);
    // 更新人数总量
    peopleTotal.value = response.data.total;
  }).catch(error => {
    console.error('Error fetching total people count:', error);
  });
  getJieKouTotal().then(response => {
    // 打印请求返回的数据
    console.log('Total JieKou count:', response.data);
    // 更新调用接口总量
    jieKouTotal.value = response.data.total;
  }).catch(error => {
    console.error('Error fetching total JieKou count:', error);
  });
  getTimeTotal().then(response => {
    // 打印请求返回的数据
    console.log('Total Time count:', response.data);
    // 更新时间总量
    timeTotal.value = response.data.total;
  }).catch(error => {
    console.error('Error fetching total Time count:', error);
  });
  getAlarmTotal().then(response => {
    // 打印请求返回的数据
    console.log('Total alarm count:', response.data);
    // 更新预警总量
    alarmTotal.value = 100;
  }).catch(error => {
    console.error('Error fetching total alarm count:', error);
  });
  getMonitorLastTenList().then(response => {
    // 打印请求返回的数据
    console.log('Total monitor count:', response.data);
    // 更新监控总量
    monitordataList.value = response.data.dataList;
    // 更新车流量预警统计图表数据
    carFlow.series[0].data = monitordataList.value;
  }).catch(error => {
    console.error('Error fetching total monitor count:', error);
  });
  getClassList().then(response => {
    // 打印请求返回的数据
    console.log('Total class count:', response.data);
    // 更新监控总量
    carCount.value = response.data.dataList[0];
    busCount.value = response.data.dataList[1];
    vanCount.value = response.data.dataList[2];
    // 更新饼状图数据
    pieChartData = [
      { value: carCount.value, name: '小汽车' },
      { value: vanCount.value, name: '厢式货车' },
      { value: busCount.value, name: '公交车' },
    ];
    category.series[0].data = pieChartData

  }).catch(error => {
    console.error('Error fetching total class count:', error);
  });
})

修改毕设vue代码，很多知识已经忘掉了，全程和gpt一起找bug，最后也没问出来什么，分析了一下应该是同时访问数据库次数太多了，让gpt帮忙修改了一下。

我：怎么让这几个函数一个一个的执行，否则会经常数据库异常
gpt: 你可以使用 JavaScript 中的 Promise 链来确保这些函数按顺序执行，并在前一个函数执行成功后再执行下一个函数。下面是一个示例代码，展示了如何使用 Promise 链来实现：

onMounted(() => {
  getPeopleTotal()
    .then(response => {
      console.log('Total people count:', response.data);
      peopleTotal.value = response.data.total;
      return getJieKouTotal(); // 返回一个 Promise 对象，使得下一个函数能够等待当前函数执行完毕后再执行
    })
    .then(response => {
      console.log('Total JieKou count:', response.data);
      jieKouTotal.value = response.data.total;
      return getTimeTotal();
    })
    .then(response => {
      console.log('Total Time count:', response.data);
      timeTotal.value = response.data.total;
      return getAlarmTotal();
    })
    .then(response => {
      console.log('Total alarm count:', response.data);
      alarmTotal.value = 100;
      return getMonitorLastTenList();
    })
    .then(response => {
      console.log('Total monitor count:', response.data);
      monitordataList.value = response.data.dataList;
      carFlow.series[0].data = monitordataList.value;
      return getClassList();
    })
    .then(response => {
      console.log('Total class count:', response.data);
      carCount.value = response.data.dataList[0];
      busCount.value = response.data.dataList[1];
      vanCount.value = response.data.dataList[2];
      pieChartData = [
        { value: carCount.value, name: '小汽车' },
        { value: vanCount.value, name: '厢式货车' },
        { value: busCount.value, name: '公交车' },
      ];
      category.series[0].data = pieChartData;
    })
    .catch(error => {
      console.error('Error fetching data:', error);
    });
});

完美解决！