Quick Start in accessing DB2 data from Node.js applications

Quick Start in accessing DB2 data from Node.js applications

We are seeing a trend of DB2 data being accessed by modern distributed applications written in new APIs and frameworks. JavaScript has become extremely popular for Web application development. JavaScript adoption was revolutionized by Node.js which makes it possible to run JavaScript on the server-side. There is an increasing interest amongst developers to write analytics applications in Node.js that need to access DB2 data (both z/OS and distributed). Modern DB2 provides a Node.js driver that makes Node.js connectivity straight forward. Below are step-by-step instructions for a basic end-to-end Node.js application on Windows for accessing data from DB2 for z/OS and DB2 distributed -

1) Install Node and its companion NPM. NPM is a tool to manage Node modules. Download the installer from https://nodejs.org/dist/v0.12.7/x64/node-v0.12.7-x64.msi.

2) Note that DB2 Node.js driver does not support Node 4 on Windows yet. Node 4 support is already available for Mac and Linux. We will have Node 4 support for Windows out very soon.

3) Install a 64-bit version of Node since DB2 Node.js driver does not support 32-bit.

4) Run the installer (in my case node-v0.12.7-x64.msi). You should see a screen like Screenshot 1.

Screenshot 1

5) Follow the instructions on license and folder choice until you reach the screen for the features you want installed. Default selection is recommended and click Next to start intsall (Screenshot 2).

Screenshot 2

6) Verify that the installation is complete by opening the command prompt and executing node -v and npm -v as shown in Screenshot 3.

Screenshot 3

7) You can write a simple JavaScript program to test the installation. Create a file called Confirmation.js with contents console.log('You have successfully installed Node and NPM.');

8) Navigate to the folder you have created the file in and run the application using node Confirmation.js. Output looks like Screenshot 4.

Screenshot 4

9) Now install the DB2 Node.js driver using the following command from Windows command line: npm install ibm_db (For NodeJS 4+, installation command would be different as follows

npm install git+https://git@github.com/ibmdb/node-ibm_db.git#v4_support).

10) Under the covers, the npm command downloads node-ibm_db package from github and includes the DB2 ODBC CLI driver to provide connectivity to the DB2 backend. You should see following output (Screenshot 5).

Screenshot 5

11) Copy the following simple DB2 access program in a file called DB2Test.js and change the database credentials to yours -

var ibmdb = require('ibm_db');

ibmdb.open("DRIVER={DB2};DATABASE=<dbname>;HOSTNAME=<myhost>;UID=db2user;PWD=password;PORT=<dbport>;PROTOCOL=TCPIP", function (err,conn) {

if (err) return console.log(err);

conn.query('select 1 from sysibm.sysdummy1', function (err, data) {

if (err) console.log(err);

else console.log(data);

conn.close(function () {

console.log('done');

});

});

});

12) Run the following command from Windows command line to execute the program: node DB2Test.js. You should see Screenshot 6, containing the output of SQL SELECT 1 from SYSIBM.SYSDUMMY1. Your simple Node application can now access DB2.

Screenshot 6

13) For connecting to DB2 for z/OS, modify the Connection URL, DB name, port, user name and password to DB2 for z/OS credentials.

14) DB2 for z/OS access needs DB2 Connect license entitlement. In most production DB2 for z/OS systems with DB2 Connect Unlimited Edition licensing, server side license activation would have already been done, in which case you don't need to do anything about licensing. If you get any license error on executing the program, server side activation may not have been done. In that case, copy the DB2 Connect ODBC client side license file into ibm_db/installer/clidriver/license folder.

15) Also make sure that the DB2 for z/OS server you are testing against has CLI packages already bound (this would have been already done as part of DB2 Connect setup on the DB2 z/OS server).

16) Run the program with DB2 for z/OS credentials and you will observe similar output as Step 12.

Enjoy your Node.js test drive with DB2!