无法将 useState 数据保存到 MongoDB 数据库
Can't save useState data to MongoDB database
我正在使用 MERN,我对此很陌生,所以我被卡住了。我正在创建一个表单,您可以在其中输入一些信息和位置,我正在尝试将该纬度和经度(存储在 markers
变量中)保存到我的 MongoDB 数据库中我尝试了一切,但最终,它不保存到数据库。
前端
const [markers, setMarkers] = useState([]);
// Function to get the lat and lng
const onMapClick = (e, props) => {
setMarkers((current) => [
...current,
{
lat: e.latLng.lat(),
lng: e.latLng.lng(),
},
]);
if (markers.length > 0) {
setMarkers(markers.slice(0, 1));
setMarkers(markers.slice(1));
}
};
return (
<form method="POST" action="/handleSubmit">
<div className="flex flex-col ml-36">
<div className="mt-6">
<p>Your full name</p>
<input
type="text"
name="ownerName"
className="border-2 border-black w-80 p-1"
/>
</div> ...
<div className="m-20">
<h1 className="text-4xl font-bold mb-5">
Where he was last seen?
</h1>
<GoogleMap
mapContainerStyle={mapContainerStyle}
zoom={13}
center={center}
onClick={onMapClick}
>
// Markers I'm trying to save to DB
<div id="mapMarkers">
{markers.map((marker) => (
<Marker
position={{ lat: marker.lat, lng: marker.lng }}
name="marker"
/>
))}
{markers.map((marker) => (
<Circle
center={{ lat: marker.lat, lng: marker.lng }}
options={optionsMarker.circle}
name="marker"
/>
))}
</div>
</GoogleMap>
</div>
<div className="m-20">
<input
type="submit"
value="Vytvoriť profil"
className="py-4 px-16 bg-yellow-500 text-2xl font-semibold rounded-lg"
/>
</div>
</form>
后端
server.js
//express
const express = require('express');
const app = express();
const bodyParser = require('body-parser');
// dotenv
require('dotenv').config();
// mongoose
const mongoose = require('mongoose');
const routesHandler = require('./routes/handler.js');
const port = process.env.PORT || 7000;
app.use(bodyParser.urlencoded({ extended: false }));
app.use(bodyParser.json({ extended: false }));
app.use('/', routesHandler);
const mongoDB = process.env.MONGO_URI;
mongoose
.connect(mongoDB, {
useNewUrlParser: true,
useUnifiedTopology: true,
})
.then(() => {
console.log('MongoDB Connected');
})
.catch((error) => {
console.log(error);
});
const db = mongoose.connection;
db.on('error', console.error.bind(console, 'Connection error:'));
app.listen(port, () => {
console.log(`Example app listening on port ${port}`);
});
后端handler.js
const express = require('express');
const router = express.Router();
const Schemas = require('../models/Schemas');
router.get('/pets', async (req, res) => {
const pets = Schemas.pets;
const ownerPets = await pets
.find({})
.populate('owner', 'map')
.exec((error, petData) => {
if (error) {
res.end('Error getting pets');
console.log(error);
} else {
res.json(petData);
}
if (petData) {
console.log('Pets found');
} else {
res.end('Pets not found');
}
});
});
router.post('/handleSubmit', async (req, res) => {
// handle Owner data
const owner = {
name: req.body.ownerName,
tel: req.body.tel,
email: req.body.email,
};
const newOwner = new Schemas.owners(owner);
try {
await newOwner.save(async (err, newUserResult) => {
if (err) {
console.log(err);
} else {
console.log('New owner created');
res.redirect('/lostpet');
res.end('New owner created');
}
});
} catch (err) {
console.log(err);
res.redirect('/');
res.end('Error creating owner');
}
// handle map coordinates
const map = {
cor: req.body.marker,
};
const newMap = new Schemas.maps(map);
try {
await newMap.save((err, newMapResult) => {
if (err) console.log(err);
else {
console.log('New map created');
res.redirect('/lostpet');
res.end('New map created');
}
});
} catch (err) {
console.log(err);
redirect('/');
res.end();
}
// handle Pet data
const pet = {
name: req.body.petName,
details: req.body.details,
lost_date: req.body.lostDate,
};
const pet_owner = newOwner;
let map_cor = newMap;
const newPet = new Schemas.pets({
name: pet.name,
details: pet.details,
lost_date: pet.lost_date,
owner: pet_owner._id,
map: map_cor,
});
try {
await newPet.save((err, newPetResult) => {
if (err) console.log(err);
else {
console.log('New pet created');
res.redirect('/lostpet');
res.end('New pet created');
}
});
} catch (err) {
console.log(err);
redirect('/');
res.end();
}
});
module.exports = router;
Schemas.js
const mongoose = require('mongoose');
const Schema = mongoose.Schema;
const ownerSchema = Schema({
name: { type: String, required: true },
tel: { type: String, required: true },
email: { type: String, required: true },
entryDate: { type: Date, default: Date.now },
});
const petSchema = Schema({
name: { type: String, required: true },
details: { type: String, required: true },
lost_date: { type: Date, required: true },
owner: { type: Schema.Types.ObjectId, ref: 'owners' },
});
const mapSchema = Schema({
cor: { type: Number, required: true },
});
const Owners = mongoose.model('owners', ownerSchema);
const Pets = mongoose.model('pets', petSchema);
const Maps = mongoose.model('maps', mapSchema);
const mySchema = { owners: Owners, pets: Pets, maps: Maps };
module.exports = mySchema;
您可以在表单上添加 onSubmit
处理程序
<form onSubmit={submitHandler}>...</form>
const submitHandler = (e) => {
e.preventDefault();
const data = {
...formInputValues, // your input values
markers
};
fetch(YOUR_SERVER_URL, {
method: "POST",
body: JSON.stringify(data),
headers: {
"Content-Type": "application/json",
},
}).then(res => {
res.json();
}).catch(e => throw new Error(e));
}
我正在使用 MERN,我对此很陌生,所以我被卡住了。我正在创建一个表单,您可以在其中输入一些信息和位置,我正在尝试将该纬度和经度(存储在 markers
变量中)保存到我的 MongoDB 数据库中我尝试了一切,但最终,它不保存到数据库。
前端
const [markers, setMarkers] = useState([]);
// Function to get the lat and lng
const onMapClick = (e, props) => {
setMarkers((current) => [
...current,
{
lat: e.latLng.lat(),
lng: e.latLng.lng(),
},
]);
if (markers.length > 0) {
setMarkers(markers.slice(0, 1));
setMarkers(markers.slice(1));
}
};
return (
<form method="POST" action="/handleSubmit">
<div className="flex flex-col ml-36">
<div className="mt-6">
<p>Your full name</p>
<input
type="text"
name="ownerName"
className="border-2 border-black w-80 p-1"
/>
</div> ...
<div className="m-20">
<h1 className="text-4xl font-bold mb-5">
Where he was last seen?
</h1>
<GoogleMap
mapContainerStyle={mapContainerStyle}
zoom={13}
center={center}
onClick={onMapClick}
>
// Markers I'm trying to save to DB
<div id="mapMarkers">
{markers.map((marker) => (
<Marker
position={{ lat: marker.lat, lng: marker.lng }}
name="marker"
/>
))}
{markers.map((marker) => (
<Circle
center={{ lat: marker.lat, lng: marker.lng }}
options={optionsMarker.circle}
name="marker"
/>
))}
</div>
</GoogleMap>
</div>
<div className="m-20">
<input
type="submit"
value="Vytvoriť profil"
className="py-4 px-16 bg-yellow-500 text-2xl font-semibold rounded-lg"
/>
</div>
</form>
后端 server.js
//express
const express = require('express');
const app = express();
const bodyParser = require('body-parser');
// dotenv
require('dotenv').config();
// mongoose
const mongoose = require('mongoose');
const routesHandler = require('./routes/handler.js');
const port = process.env.PORT || 7000;
app.use(bodyParser.urlencoded({ extended: false }));
app.use(bodyParser.json({ extended: false }));
app.use('/', routesHandler);
const mongoDB = process.env.MONGO_URI;
mongoose
.connect(mongoDB, {
useNewUrlParser: true,
useUnifiedTopology: true,
})
.then(() => {
console.log('MongoDB Connected');
})
.catch((error) => {
console.log(error);
});
const db = mongoose.connection;
db.on('error', console.error.bind(console, 'Connection error:'));
app.listen(port, () => {
console.log(`Example app listening on port ${port}`);
});
后端handler.js
const express = require('express');
const router = express.Router();
const Schemas = require('../models/Schemas');
router.get('/pets', async (req, res) => {
const pets = Schemas.pets;
const ownerPets = await pets
.find({})
.populate('owner', 'map')
.exec((error, petData) => {
if (error) {
res.end('Error getting pets');
console.log(error);
} else {
res.json(petData);
}
if (petData) {
console.log('Pets found');
} else {
res.end('Pets not found');
}
});
});
router.post('/handleSubmit', async (req, res) => {
// handle Owner data
const owner = {
name: req.body.ownerName,
tel: req.body.tel,
email: req.body.email,
};
const newOwner = new Schemas.owners(owner);
try {
await newOwner.save(async (err, newUserResult) => {
if (err) {
console.log(err);
} else {
console.log('New owner created');
res.redirect('/lostpet');
res.end('New owner created');
}
});
} catch (err) {
console.log(err);
res.redirect('/');
res.end('Error creating owner');
}
// handle map coordinates
const map = {
cor: req.body.marker,
};
const newMap = new Schemas.maps(map);
try {
await newMap.save((err, newMapResult) => {
if (err) console.log(err);
else {
console.log('New map created');
res.redirect('/lostpet');
res.end('New map created');
}
});
} catch (err) {
console.log(err);
redirect('/');
res.end();
}
// handle Pet data
const pet = {
name: req.body.petName,
details: req.body.details,
lost_date: req.body.lostDate,
};
const pet_owner = newOwner;
let map_cor = newMap;
const newPet = new Schemas.pets({
name: pet.name,
details: pet.details,
lost_date: pet.lost_date,
owner: pet_owner._id,
map: map_cor,
});
try {
await newPet.save((err, newPetResult) => {
if (err) console.log(err);
else {
console.log('New pet created');
res.redirect('/lostpet');
res.end('New pet created');
}
});
} catch (err) {
console.log(err);
redirect('/');
res.end();
}
});
module.exports = router;
Schemas.js
const mongoose = require('mongoose');
const Schema = mongoose.Schema;
const ownerSchema = Schema({
name: { type: String, required: true },
tel: { type: String, required: true },
email: { type: String, required: true },
entryDate: { type: Date, default: Date.now },
});
const petSchema = Schema({
name: { type: String, required: true },
details: { type: String, required: true },
lost_date: { type: Date, required: true },
owner: { type: Schema.Types.ObjectId, ref: 'owners' },
});
const mapSchema = Schema({
cor: { type: Number, required: true },
});
const Owners = mongoose.model('owners', ownerSchema);
const Pets = mongoose.model('pets', petSchema);
const Maps = mongoose.model('maps', mapSchema);
const mySchema = { owners: Owners, pets: Pets, maps: Maps };
module.exports = mySchema;
您可以在表单上添加 onSubmit
处理程序
<form onSubmit={submitHandler}>...</form>
const submitHandler = (e) => {
e.preventDefault();
const data = {
...formInputValues, // your input values
markers
};
fetch(YOUR_SERVER_URL, {
method: "POST",
body: JSON.stringify(data),
headers: {
"Content-Type": "application/json",
},
}).then(res => {
res.json();
}).catch(e => throw new Error(e));
}