Javascript 我正在创建一个登录日志演示
当我发布到我的注册路径时,我使用以下代码检查数据库中的用户,但我的析构函数显示用户为未定义,但我已经定义了用户Javascript 我正在创建一个登录日志演示,javascript,node.js,Javascript,Node.js,当我发布到我的注册路径时,我使用以下代码检查数据库中的用户,但我的析构函数显示用户为未定义,但我已经定义了用户 updateUser(userDetails){ User.find({}, function (err, foundItems){ console.log(foundItems[0].email) const checkUserByEmail = foundItems.find((u)=> u.email
updateUser(userDetails){
User.find({}, function (err, foundItems){
console.log(foundItems[0].email)
const checkUserByEmail = foundItems.find((u)=> u.email === userDetails.email)
console.log(checkUserByEmail)
if(checkUserByEmail){
console.log("adsakhdsk")
return {
error : "user already exist"
}
}
const user = new User({
email : userDetails.email,
password: userDetails.password
})
user.save()
return {
user : userDetails
}
})
}
}
这是我注册用户的注册方法
register = (req, res) => {
const userDetails = {
email: req.body.email,
password: req.body.password,
}
const { user , error } = usersdb.updateUser(userDetails)
console.log([user , error])
}
我得到的错误
TypeError: Cannot destructure property 'user' of 'usersdb.updateUser(...)' as it is undefined.
at register (C:\Users\USER\Desktop\nodejs\login-logut-demo\api\auth\router.js:13:13)
at Layer.handle [as handle_request] (C:\Users\USER\Desktop\nodejs\login-logut-demo\node_modules\express\lib\router\layer.js:95:5)
at next (C:\Users\USER\Desktop\nodejs\login-logut-demo\node_modules\express\lib\router\route.js:137:13)
at Route.dispatch (C:\Users\USER\Desktop\nodejs\login-logut-demo\node_modules\express\lib\router\route.js:112:3)
at Layer.handle [as handle_request] (C:\Users\USER\Desktop\nodejs\login-logut-demo\node_modules\express\lib\router\layer.js:95:5)
at C:\Users\USER\Desktop\nodejs\login-logut-demo\node_modules\express\lib\router\index.js:281:22
at Function.process_params (C:\Users\USER\Desktop\nodejs\login-logut-demo\node_modules\express\lib\router\index.js:335:12)
at next (C:\Users\USER\Desktop\nodejs\login-logut-demo\node_modules\express\lib\router\index.js:275:10)
at Function.handle (C:\Users\USER\Desktop\nodejs\login-logut-demo\node_modules\express\lib\router\index.js:174:3)
at router (C:\Users\USER\Desktop\nodejs\login-logut-demo\node_modules\express\lib\router\index.js:47:12)
at Layer.handle [as handle_request] (C:\Users\USER\Desktop\nodejs\login-logut-demo\node_modules\express\lib\router\layer.js:95:5)
at trim_prefix (C:\Users\USER\Desktop\nodejs\login-logut-demo\node_modules\express\lib\router\index.js:317:13)
at C:\Users\USER\Desktop\nodejs\login-logut-demo\node_modules\express\lib\router\index.js:284:7
at Function.process_params (C:\Users\USER\Desktop\nodejs\login-logut-demo\node_modules\express\lib\router\index.js:335:12)
at next (C:\Users\USER\Desktop\nodejs\login-logut-demo\node_modules\express\lib\router\index.js:275:10)
at C:\Users\USER\Desktop\nodejs\login-logut-demo\node_modules\body-parser\lib\read.js:130:5
数据库请求是异步的。 我怀疑在您的情况下可能发生的是,在updateUser方法从数据库检索数据之前,您尝试读取'user'的值 我建议您研究nodeJS&等待异步语法
updateUser(userDetails){
return new Promise((resolve, reject) => {
User.find({}, function (err, foundItems) {
console.log(foundItems[0].email)
const checkUserByEmail = foundItems.find((u) => u.email === userDetails.email)
console.log(checkUserByEmail)
if (checkUserByEmail) {
console.log("adsakhdsk")
resolve({
error: "user already exist"
})
}
const user = new User({
email: userDetails.email,
password: userDetails.password
})
user.save()
resolve({
user: userDetails
})
})
})
}
register = async (req, res) => {
const userDetails = {
email: req.body.email,
password: req.body.password,
}
const { user, error } = await usersdb.updateUser(userDetails)
console.log([user, error])
}
这是解决您的错误的可能方法
这里发生的是updateUser方法现在返回一个承诺,可以使用async/await处理该承诺
基本上,它使我们能够告诉程序,等这段代码执行完毕。
当您调用resolve()
时,承诺结束,并抛出异常reject()
异步函数返回的数据作为
resolve()
回调的参数发送。从外观上看,您没有从updateUser
返回任何内容,因此usersdb.updateUser(userDetails)
正在解析为未定义的。此代码是否引发任何错误,或者当您登录时,用户
只是未定义
?@sandmann我添加了我得到的错误。我在items.find block中返回错误和用户nodeJS中的任何数据库查询都是异步的。我建议将updateUser方法封装到promise中,并使register成为一个异步函数实际上,usersdb.updateUser(userDetails)
正在解析为未定义的
。必须从updateUser
方法返回具有user
属性的对象。尝试返回User.find的结果(如果返回任何内容)。