Connect to the database in the framework automatically generated by express
  
connect.js Code
const mysql = require("mysql");
const db = mysql.createConnection({
  host: "localhost",
  port: 3306,
  user: "root",
  database: "ningxia"
})
db.connect((error) => {
  if (error) {
    console.log(error)
    console.log("")
  } else {
    console.log("")
  }
})
module.exports = dbintroduce the connect.js file into the Index.js of api, and the small blackboard indicates that the connection failed
