javascript - 引用错误: email is not defined

Question

嗨，请帮助陷入困境的开发人员。

我一整天都在尝试解决这个问题，但没有成功。基本上我想做的就是从我的 AddUsers 类发布并将其存储到我的 sql 数据库中。这是一个非常简单的查询，但已经让我变得更好了!状态会在更改时更新，但似乎是 server.js 的问题(错误包含在帖子底部)

服务器.js

app.post("/admin-Add-Users", function(req, res) {
  var request = new sql.Request();

  // query to the database and get the records
  request.query(
    "insert into Login (email, password) values ('" +
      req.body.email +
      "','" +
      req.body.password +
      "')",
    function(err, recordset) {
      if (err) console.log(err);
    }
  );
  res.send({ message: "Success" });
});

添加用户类

class AddUsers extends React.Component {
  constructor() {
    super();

    this.state = { users: [], email: "", password: "" };
    this.onSubmit = this.handleSubmit.bind(this);
  }

  handleSubmit(e) {
    e.preventDefault();
    const data = { email: this.state.email, password: this.state.password };

    fetch("/admin-Add-Users", {
      method: "POST", // or 'PUT'
      headers: {
        "Content-Type": "application/json"
      },
      body: JSON.stringify(data)
    })
      .then(response => response.json())
      .then(data => {
        console.log("Success:", data);
      })
      .catch(error => {
        console.error("Error:", error);
      });
  }

  render() {
    console.log(this.state.users);
    return (
      <div>
        <LoginForm></LoginForm>

        <form>
          <input
            type="text"
            placeholder="email"
            value={this.state.email}
            onChange={e => this.setState({ email: e.target.value })}
          />
          <input
            type="text"
            placeholder="password"
            value={this.state.password}
            onChange={e => this.setState({ password: e.target.value })}
          />
          <input type="submit" onClick={this.onSubmit} />
        </form>
      </div>
    );
  }
}

ReferenceError: email is not defined

更新:在尝试了给我的建议后，我现在又出现了一个新错误。

Error: SyntaxError: Unexpected token < in JSON at position 0 

Answer 1

您的 React 应用程序似乎没有任何问题。

The problem is at your API end where you're formulating an insert query without actually reading the request json content (email & password) fields.

您可以在生成查询之前添加以下行。

// create sql obj
...
var email = req.body.email;
var password = req.body.password;

...
// your query