url 中的参数未定义 - axios、react、express答案

【问题标题】：params in url undefined - axios, react, expressurl 中的参数未定义 - axios、react、express
【发布时间】：2022-01-08 19:04:00
【问题描述】：

我正在尝试使用代码从 mysql 数据库中删除一些数据：

app.delete("/api/deleteHomework/:homeworkName", (req, res) => {
    const homeworkName = req.params.homeworkName

    connection.query(
            "DELETE FROM homework WHERE name = ?",
            [homeworkName],
            (err, result) => {
                if(result){
                    res.send({ message: result })
                    console.log(result)
                }
                if(err){
                    console.log(err)
                }
            }
    )
})

然后homeworkName从前端传入代码：

  const deleteHw = (homework) => {
        Axios.delete(`http://localhost:1337/api/deleteHomework/${homework}`)
        .then((response) => {
            if(response){
                console.log(response)
            } else{
                console.log("error")
            }
        })
    }

<DeleteForeverIcon className={classes.deleteHwIcon} onClick={() => {deleteHw(value.homeworkName)}} />

但是它说 url 中的参数是未定义的：网址：“http://localhost:1337/api/deleteHomework/undefined”

【问题讨论】：

标签： javascript reactjs express http axios

【解决方案1】：

直接在删除函数中传递props“值”

export default function YourComponent({ value }) {
...

const deleteHw = () => {
  Axios.delete(`http://localhost:1337/api/deleteHomework/${value.homeworkName}`) // here
  .then((response) => {
    if(response){
      console.log(response)
    } else{
      console.log("error")
    }
  })
}
    
<DeleteForeverIcon className={classes.deleteHwIcon} onClick={deleteHw} />

背面

app.delete('/api/deleteHomework/:homeworkName', (req, res) => {
  connection.query(`DELETE FROM homework WHERE name=${req.params.homeworkName}`, (err, result) => {
    if (err) {
      console.log(err);
    } else {
      res.json(result);
    }
  });
});

【讨论】：