React 和 mySQL 错误 \'Error: ER_EMPTY_QUERY: Query was empty \'答案

【问题标题】：React and mySQL errors 'Error: ER_EMPTY_QUERY: Query was empty 'React 和 mySQL 错误 \'Error: ER_EMPTY_QUERY: Query was empty \'
【发布时间】：2022-08-05 22:50:34
【问题描述】：

我正在尝试连接我的 React 和 mySQL 连接，并且我已经使用和不使用密码完成了它，并且密码似乎给了我一个查询是空的错误，但是当我打印 req.body 时，它有所有我的信息。我在查询之前打印 req.body，所以我不确定为什么它认为它是空的。

{ 姓名：\'123\'，年龄：\'123\'，地址：\'123\'，租金：\'123\'，
租赁长度：\'1\'，开始日期：\'2022-06-01\'}

  code: \'ER_EMPTY_QUERY\',
  errno: 1065,
  sqlMessage: \'Query was empty\',
  sqlState: \'42000\',
  index: 0,
  sql: undefined

这是 index.js（服务器）

const express = require(\'express\')
const app = express()
const mysql = require(\'mysql\')
const cors = require(\'cors\')

app.use(cors())
app.use(express.json())

const db = mysql.createConnection({
    user: \'root\',
    host: \'localhost\',
    password: \'password\',
    database: \'tenantsystem\'
});

app.post(\'/create\', (req, res) => {
    console.log(req.body)
    const name = req.body.name
    const age = req.body.age
    const address = req.body.address
    const rent = req.body.name
    const leaseLength = req.body.leaseLength
    const startDate = req.body.startDate

    db.query(\'INSERT INTO tenants (name, age, address, rent, lease_length, start_date) VALUES (?,?,?,?,?,?)\'[name, age, address, rent, leaseLength, startDate], (err, result) => {
        if (err) {
            console.log(err)
        }
        else {
            res.send(\"Values Inserted\")
        }
    });
});

app.listen(3001, () => {
    console.log(\"Server is running...\")
})

这是前端 App.js (react)

import \'./App.css\';
import { useState } from \'react\';
import Axios from \'axios\';


function App() {
  const [name, setName] = useState(\'\')
  const [age, setAge] = useState(\'\')
  const [address, setAddress] = useState(\'\')
  const [rent, setRent] = useState(\'\')
  const [leaseLength, setLeaseLength] = useState(\'\')
  const [startDate, setStartDate] = useState(\'\')
  const displayInfo = () => {
    console.log(name + age + address + rent + leaseLength + startDate)
  }


  const addTenant = () => {
    console.log(name)
    Axios.post(\'http://localhost:3001/create\', {
      name: name,
      age: age,
      address: address,
      rent: rent,
      leaseLength: leaseLength,
      startDate: startDate,
    }).then(() => {
      console.log(\'Success\');
    })
  }

  return (
    <div className=\"App\">
      <div className=\"information\">
        <label>Name: </label>
        <input type=\"text\" onChange={(e) => {
          setName(e.target.value)
        }} />
        <label>Age: </label>
        <input type=\"number\" onChange={(e) => {
          setAge(e.target.value)
        }} />
        <label>Address: </label>
        <input type=\"text\" onChange={(e) => {
          setAddress(e.target.value)
        }} />
        <label>Rent: </label>
        <input type=\"number\" onChange={(e) => {
          setRent(e.target.value)
        }} />
        <label> lease length in months</label>
        <input type=\"number\" onChange={(e) => {
          setLeaseLength(e.target.value)
        }} />
        <label>start date: </label>
        <input type=\"date\" onChange={(e) => {
          setStartDate(e.target.value)
        }} />
        <button onClick={addTenant}> Add Tenant</button>
      </div>
    </div>
  );
}

export default App;

标签： mysql node.js reactjs

【解决方案1】：

我认为可能为时已晚，但无论如何您在这里忘记的是“，” 在查询和参数之间

【讨论】：