中變量的作用域我遇到了,我似乎被猜測它是一個JS變量範圍的問題有固定的一個MySQL連接錯誤。JS哈皮JS路由處理
在路由處理程序中,我已經注意到拋出以下MySQL錯誤的代碼:PROTOCOL_ENQUEUE_AFTER_FATAL_ERROR
,幷包含下面的工作代碼。
require('dotenv').config();
const Hapi = require('hapi');
const mysql = require('mysql');
const Joi = require('joi');
const query = require('./lib/mysql/query');
const server = new Hapi.Server();
server.connection({
host: process.env.SERVER_HOST,
port: process.env.SERVER_PORT
});
const dbOne = mysql.createConnection({
host: process.env.DB_HOST,
user: process.env.DB_USER_ONE,
password: process.env.DB_PASSWORD_ONE
});
const dbTwo = mysql.createConnection({
host: process.env.DB_HOST_TEST,
user: process.env.DB_USER_TWO,
password: process.env.DB_PASSWORD_TWO,
});
server.route({
method: 'GET',
path:'/my-route',
config: {
validate: {
query: {
useDatabase2: Joi.valid('true'),
},
},
},
handler: (req, reply) => {
const useDatabase2 = req.query.useDatabase2 === 'true';
// This didn't work...
/*
const db = useDatabase2 ? dbTwo : dbOne;
db.query(query, (err, rows) => {
if (err) {
reply({
statusCode: 500,
error: "Internal Server Error",
message: err,
}).code(500);
} else {
// ...do something with the data
}
});
*/
// This works...
if (useDatabase2) {
dbTwo.query(query, (err, rows) => {
if (err) {
reply({
statusCode: 500,
error: "Internal Server Error",
message: err,
}).code(500);
} else {
// ...do something with the data
}
});
} else {
dbOne.query(query, (err, rows) => {
if (err) {
reply({
statusCode: 500,
error: "Internal Server Error",
message: err,
}).code(500);
} else {
// ...do something with the data
}
});
}
}
});
server.start(err => {
if (err) throw err;
});
我曾假定const db
只是給它自己的範圍內的原始變量(dbOne或dbTwo)的引用,並停止在每個請求的末尾存在。
是在db
變量真正與自己發生衝突並導致MySQL連接失敗!?