JavaScript 回调方法无法调用从模块导入的函数

Question

我正在尝试在 NodeJS 中实现 Oracle 数据库更改通知。

函数subscribeTimesheetEvent正在订阅通知，输入之一是回调方法。在我的例子中，它是 myCallback 函数。这个函数被调用并且工作正常，除了它没有看到从 dbFunctions 文件导入的 executeQuery 函数。我通过从 dbFunctions 导入在其他地方使用了这个函数，它工作正常。我怀疑我在 myCallback 函数中遇到了一些我不太熟悉的范围问题。

const oracledb = require('oracledb');
const logger = require('../logger')
const common = require('../common');
let { executeQuery } = require('../db/dbFunctions');
const { getQueryObj, queries } = require('../db/queries')

require('dotenv').config();


function myCallback(message) {
            logger.log(logger.LOG_LEVEL.INFO, JSON.stringify(message));
            logger.log(logger.LOG_LEVEL.INFO, message.type);
            if (message.type == oracledb.SUBSCR_EVENT_TYPE_DEREG) {
                // clearInterval(interval);
                logger.log(logger.LOG_LEVEL.INFO, "Deregistration has taken place...");
                return;
            }
            message.tables.forEach(table => {
                logger.log(logger.LOG_LEVEL.INFO, `--> --> Table Name: ${table.name}`);
                // Note table.operation and row.operation are masks of
                // oracledb.CQN_OPCODE_* values
                logger.log(logger.LOG_LEVEL.INFO, `--> --> Table Operation: ${table.operation}`);
                if (table.rows) {
                    logger.log(logger.LOG_LEVEL.INFO, `--> --> Table Rows: table.rows.length`);
                    table.rows.forEach(row => {
                        if(row.operation ==oracledb.CQN_OPCODE_INSERT ){
                            executeQuery("select * from chatbot_msg where rowid = :rowid", [row.rowid])
                                .then(msg=>logger.log(logger.LOG_LEVEL.INFO, JSON.stringify(msg)));
                            
                        }
                    });
                }
            });
            logger.log(logger.LOG_LEVEL.INFO, Array(61).join("="));
            // }  
        }
    
async function subscribeTimesheetEvent() {
    logger.log(logger.LOG_LEVEL.INFO, 'Registering Oracle Change Notification');
    const connection = await oracledb.getConnection();
    // await connection.unsubscribe('mysub');

    const options = {
        sql: `SELECT * FROM chatbot_msg`,  // query of interest
        callback: myCallback,                // method called by notifications
        qos: oracledb.SUBSCR_QOS_ROWIDS,
        port: 9091,
        timeout: 120,
        operations: oracledb.CQN_OPCODE_INSERT
    };

    await connection.subscribe('tsMsgSub', options);
}

module.exports.subscribeTimesheetEvent = subscribeTimesheetEvent;

调试截图： executeQuery 显示为未定义。

Answer 1

导入整个文件而不是解构可以解决错误。不知道为什么..

导入代码：

const dbFunctions = require('../db/dbFunctions');

调用函数：

dbFunctions.executeQuery("select * from chatbot_msg where rowid = :rowid", [row.rowid])
                                .then(msg=>logger.log(logger.LOG_LEVEL.INFO, JSON.stringify(msg)));

JavaScript 回调方法无法调用从模块导入的函数

JavaScript Callback method not able to call function imported from module

javascript

node.js

node-oracledb