NextJs TypeError:无法读取未定义的属性(读取'0')
NextJs TypeError:无法读取未定义的属性(读取'0')
提问于 2022-03-31 16:20:16
我试图连接到Mongodb来定义连接、断开连接并在API中使用它。我收到这个无法读取未定义属性(读取'0)的TypeError。我使用控制台来检查是否包含与此Mongoose实例关联的所有连接的数组，但是是否只有0而不是连接列表。下面是代码片段。
import mongoose from 'mongoose';
const connection = {};
async function connect() {
if (connection.isConnected) {
console.log('already connected');
}
if (mongoose.connections.length > 0) {
connection.isConnected = mongoose.connections[0].readyState;
console.log('cone', connection.isConnected);
if (connection.isConnected === 1) {
console.log('use previous connection');
return;
}
await mongoose.disconnect();
}
const dbConnect = mongoose.connect(process.env.MONGODB_URI, {
// useNewUrlParser: true,
useUnifiedTopology: true,
// useCreateIndex: true,
});
console.log('new connection');
connection.isConnected = dbConnect.connections[0].readyState;
}
async function disconnect() {
if (connection.isConnected) {
if (process.env.NODE_ENV === 'production') {
await mongoose.disconnect();
connection.isConnected = false;
} else {
console.log('not disconnected');
}
}
}
const db = { connect, disconnect };
export default db;
我得到的错误是这个
error - (api)\utils\db.js (25:49) @ Object.connect
TypeError: Cannot read properties of undefined (reading '0')
23 | });
24 | console.log('new connection');
> 25 | connection.isConnected = dbConnect.connections[0].readyState;
| ^
26 | console.log("cone1", connection.isConnected);
27 | }
回答 1
Stack Overflow用户
回答已采纳
发布于 2022-04-01 10:35:50
mongoose.connect()上没有连接类型。所以只需要删除我正在寻找的connections.readyState。
import mongoose from 'mongoose';
const connection = {};
async function connect() {
if (connection.isConnected) {
console.log('already connected');
return;
}
if (mongoose.connections.length > 0) {
connection.isConnected = mongoose.connections[0].readyState;
if (connection.isConnected === 1) {
console.log('use previous connection');
return;
}
await mongoose.disconnect();
}
const options = {
useUnifiedTopology: true,
useNewUrlParser: true,
};
const uri = process.env.MONGODB_URI;
const db = mongoose.connect(uri, options);
console.log('new connection');
connection.isConnected = db
if (!uri) {
throw new Error('Add your Mongo URI to .env');
}
}
async function disconnect() {
if (connection.isConnected) {
if (process.env.NODE_ENV === 'production') {
await mongoose.disconnect();
connection.isConnected = false;
} else {
console.log('not disconnected');
}
}
}
const db_export = { connect, disconnect };
export default db_export;
页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：
https://stackoverflow.com/questions/71695987
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