Res.redirect在nodejs webapp中使用express时不是一个函数

Question

如果所需数据成功更新，我正在尝试重定向到"/admin"路由，但我收到res.redirect不是一个函数的错误。我也尝试过编写返回 res.redirect，但它也不起作用。节点专家，请帮忙。在这里，我只是在 reg.no 上找到学生记录。基础并使用其标记更新记录并重定向到管理页面。

app.post('/admin/midterm/marks',(req,res)=>{
var m_written=[];
var m_practical=[];

var myjson=JSON.stringify(req.body);
course.subjects.map(sub=>{
if(!Array.isArray(req.body[`${sub}`]))
{
var p={subject:sub,mark:req.body[`${sub}`]}
m_written.push(p);
}
else{
var p={subject:sub,mark:req.body[`${sub}`][0]};
var q={subject:sub,mark:req.body[`${sub}`][1]};
m_written.push(p);
m_practical.push(q);
}

});
var first={
sem:course._id,
marks_sem:[{
term:ms,
m_written:m_written,
m_practical:m_practical
}]
}
if(!StudentRecord.total.length )
{
Student.updateOne({_id:check_Id},{total:first},function(err,res){
if(err)
{console.log("error");}
res.redirect('/admin');
});
}
else{
var flag=0;
StudentRecord.total.map(record=>{
if(record.sem==required_sem)
{
flag=1;
record.marks_sem.push(first.marks_sem);
Student.updateOne({_id:check_Id},{total:StudentRecord.total},function(err,res){
if(err)
{console.log("error");}
res.redirect('/admin');
});
}
});
if(flag==0)
{
StudentRecord.total.push(first);
Student.updateOne({_id:check_Id},{total:StudentRecord.total},function(err,res){
if(err)
{console.log("error");}
res.redirect('/admin');
});
}
}});

Answer 1

您可以在回调中覆盖res。在回调result中命名第二个参数，一切正常。

app.post("/admin/midterm/marks", (req, res) => {
var m_written = [];
var m_practical = [];
var myjson = JSON.stringify(req.body);
course.subjects.map((sub) => {
if (!Array.isArray(req.body[`${sub}`])) {
var p = { subject: sub, mark: req.body[`${sub}`] };
m_written.push(p);
} else {
var p = { subject: sub, mark: req.body[`${sub}`][0] };
var q = { subject: sub, mark: req.body[`${sub}`][1] };
m_written.push(p);
m_practical.push(q);
}
});
var first = {
sem: course._id,
marks_sem: [
{
term: ms,
m_written: m_written,
m_practical: m_practical,
},
],
};
if (!StudentRecord.total.length) {
Student.updateOne({ _id: check_Id }, { total: first }, function (err, result) {
if (err) {
console.log("error");
}
res.redirect("/admin");
});
} else {
var flag = 0;
StudentRecord.total.map((record) => {
if (record.sem == required_sem) {
flag = 1;
record.marks_sem.push(first.marks_sem);
Student.updateOne(
{ _id: check_Id },
{ total: StudentRecord.total },
function (err, result) {
if (err) {
console.log("error");
}
res.redirect("/admin");
}
);
}
});
if (flag == 0) {
StudentRecord.total.push(first);
Student.updateOne(
{ _id: check_Id },
{ total: StudentRecord.total },
function (err, result) {
if (err) {
console.log("error");
}
res.redirect("/admin");
}
);
}
}
});