1、Error: ER_CON_COUNT_ERROR: Too many connections（太多连接池，超出上限）
    如何查看连接池，先到mysql的bin目录下面 用管理员终端打开该目录
    然后起命令登录**mysql -u root -p**
    注意：命令后面要加分号不然不知道你的语句是否结束
    查看 连接池限制的语句 show variables like ‘%max_connections%’
    image.png

    2、使用node-xlsx 第三方插件将excel表格变为数组，然后继续操作

    1. // 引入 node-xlsx 模块
    2. const xlsx = require('node-xlsx');
    3. const db  = require('./db.js')
    5. // excel文件类径
    6. const excelFilePath = './data/collegeSummary.xls'
    8. //解析excel, 获取到所有sheets
    9. const sheets = xlsx.parse(excelFilePath);
    11. // 查看页面数
    12. // console.log(sheets.length);
    14. // 打印页面信息..
    15. const sheet = sheets[0];
    16. const allCollegeData = sheet.data.slice(3)
    18. // db.js
    19. const mysql = require("mysql");
    20. const defConfig = {
    21.   host: "192.168.1.234",
    22.   user: "zywy",
    23.   password: "Csqz$%^888",
    24.   database: "wangke", // 数据库名
    25.   port: "3306",
    26. };
    27. console.log('allCollegeData',allCollegeData)
    28. const connection = mysql.createConnection(defConfig);
    30. connection.connect((err) => {
    31.   if (err) {
    32.     console.log("数据库连接失败");
    33.     throw err;
    34.   }
    35. });
    36. let regionIndex = 0;
    37. for(let i = 0; i < allCollegeData.length; i ++) {
    38.   let querySql = '';
    40.   console.log(`数组长度：${allCollegeData.length}，当前索引：${i}, 当前插入项：${allCollegeData[i]}`)
    41.   if(allCollegeData[i].length === 1){
    42.     //说明是地区项
    43.     const currentRegion = allCollegeData[i][0].replace(/\（.*\）/,'');
    44.     regionIndex = regionIndex + 1
    45.     querySql = `insert into college_region(region) values('${currentRegion}')`;
    46.   }else{
    47.     const item = allCollegeData[i]
    48.     querySql = `insert into college_summary(college_name, college_code, competent_department, college_region, college_levels, region_id) values
    49.     ('${item[1]}', '${item[2]}', '${item[3]}', '${item[4]}', '${item[5]}', '${regionIndex}')`;
    50.   }
    52.   connection.query(querySql);
    54.   if(i === allCollegeData.length -1 ) {
    55.     console.log('已经处理完毕！')
    56.   }
    57. }