CODEWITHSUNDEEP
javascriptnode.jstypescriptes6-modulesnode-oracledb
Murali
Murali

Reputation: 33

How to define typescript/Oracledb npm connection in class and method format?

I'm trying to connect with npm Oracledb using typescript and in the format of class and module using typescript. For example,

Import {Oracledb} from 'oracledb'
class ConnectDAO{

     public ConnectionDB(): connection{
         let connection = Oracledb.getConnection(// connection string);
         Return connection;
     }

     public fetchData(connection): recordset{
          connection.execute('query')
          Return rs;
     }

}

can anyone please help to achieve this issue

Upvotes: 2

Views: 6363

Answers (2)

Abdullah
Abdullah

Reputation: 2973

Install below packages

npm i  oracledb @types/oracledb  --save

database.ts

import OracleDB from 'oracledb';

export default class DatabaseConnection {
    private oracleDB = OracleDB;
    private dbConfig = {
        user: "<<USER_NAME>>",
        password: "<<USER_PASSWORD>>",
        connectString: "(DESCRIPTION =(ADDRESS = (PROTOCOL = TCP)(HOST=<<YOUR_IP>>)(PORT = <<YOUR_PORT>>))(CONNECT_DATA =(SERVICE_NAME='<<YOUR_SERVICE_NAME>>')))"
    }

    public async init(): Promise<void> {
    }

    public async connectWithDB() {
        return new Promise((resolve, reject) => {
            this.oracleDB.getConnection(this.dbConfig, (err, connection) => {
                if (err) {
                    reject(err.message);
                }
                console.log('Connected with Database...');
                resolve(connection);
            });
        });
    }

    public doRelease(connection) {
        connection.release((err) => {
            if (err)
                console.error(err.message);
            console.log('connection released');
        });
    }
}

App.js

Import database file in your App.js/Service.js File

import DatabaseConnection from './database';

Create a class variable for the same

public dbConnect = new DatabaseConnection;

Add below method in same file

private async connectToDB() {
    await this.dbConnect.connectWithDB().then(async (connection: any) => {
        await connection.execute("SELECT * FROM User", [], (err, result) => {
            if (err) {
                console.error(err.message);
            }
            console.log(result.metaData);
        });
        this.dbConnect.doRelease(connection);
    }).catch(error => {
        console.log(error);
    });
}

enter image description here

Upvotes: 1

blorkfish
blorkfish

Reputation: 22854

Here is a full example. Just fill in your connection string...

import * as oracledb from 'oracledb';

let testConfig: oracledb.IConnectionAttributes = {
    user: `scott`,
    password: `tiger`,
    connectString: "(DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=..."
}

class ConnectDAO {
    public async ConnectionDB(): Promise<oracledb.IConnection> {
        return await oracledb.getConnection(testConfig);
    }
    public fetchData(connection: oracledb.IConnection):
        oracledb.IPromise<oracledb.IExecuteReturn> {
        return connection.execute('SELECT CURRENT_TIMESTAMP FROM dual');
    }
}

async function connectAndExecute() {
    let connectDao = new ConnectDAO();
    try {
        let connection = await connectDao.ConnectionDB();
        let results = await connectDao.fetchData(connection);
        console.log(`results : ${JSON.stringify(results, null, 4)}`)
    } catch (err) {
        console.log(`error caught ${err}`);
    }
}

connectAndExecute();

Upvotes: 4

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