Connect Using the SAP HANA Node.js Interface

Ensure you have Node.js installed and check its version. Enter the following command:

node -v  

If Node.js is installed, the currently installed version is returned, such as v16.15.1.

If Node.js is not installed, download the long-term support (LTS) version of Node.js from Download Node.js.

If an install for Node.js is not provided on Linux, you may choose to install it via a package manager. For more details, please navigate to this link.

During the installation, there is no need to install Chocolatey.

The SAP HANA client provides a 32-bit and a 64-bit install, as does Node.js. The Node.js driver provided with the SAP HANA client is available for 64-bit only. For further details on supported versions, see SAP Note 3165810 - SAP HANA Client Supported Platforms.

Another option is to use a docker image that contains Node.js as shown below.

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docker run -it --name=nodealpine node:alpine /bin/bash

Node.js packages are available using NPM, which is the standard package manager for Node.js.

1. Enter hana client, and click Search.

   

   The page for the SAP HANA Node.js package on npm is shown below.

   

   It contains additional sample code, a weekly download counter, information about previous versions and the command to install the package using the npm command line interface (cli).

2. Create a folder named node and enter the newly created directory.

   Shell (Microsoft Windows)

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   mkdir %HOMEPATH%\HANAClientsTutorial\node
   cd %HOMEPATH%\HANAClientsTutorial\node
   

   Shell (Linux or Mac)

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   mkdir $HOME/HANAClientsTutorial/node
   cd $HOME/HANAClientsTutorial/node
   

3. Initialize the project and install the hana-client driver from NPM.

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   npm init -y
   npm install @sap/hana-client
   

   The hana-client driver contains native libraries as shown below.

   

   When installed using NPM, the native libraries for all available platforms are downloaded. The following environment variable can be used to remove the other platforms reducing the size of the project. For additional details, see Node.js Environment Variables.

   Shell (Microsoft Windows)

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   set HDB_NODE_PLATFORM_CLEAN=1
   npm uninstall @sap/hana-client
   npm install @sap/hana-client
   

   Shell (Linux or Mac)

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   export HDB_NODE_PLATFORM_CLEAN=1
   npm uninstall @sap/hana-client
   npm install @sap/hana-client
   

   ---

   The hana-client driver is also available from the HANA client install folder. The install location was set during the install.

   Shell (Microsoft Windows)

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   cd C:\SAP\hdbclient\node
   npm install
   cd %HOMEPATH%\HANAClientsTutorial\node
   npm install C:\SAP\hdbclient\node
   

   If you encounter an error about permissions, on Microsoft Windows, run or open the command prompt as an administrator, or use sudo on Linux or Mac.

4. The following command lists the Node.js modules that are now installed locally into the HANAClientsTutorial\node folder.

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   npm list
   

   

Some Tips

At this point, the SAP HANA client module has been installed into the HANAClientsTutorials\node\node_modules folder and added as a dependency in the packages.json file. The following is some extra optional information on NPM.

---

Node.js modules can also be installed globally. To see the list of Node.js modules installed globally enter the following command.

The depth parameter can be used to specify the number of levels to show when displaying module dependencies. By setting depth=x, a tree-structure is outputted that shows modules that are x levels below the top-level module.

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npm list -g
npm list -g --depth=0

Command line help for NPM is available. A few examples of this are shown below.

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npm help
npm help list

Additional information can be found out for a module, such as the debug module, via the info command.

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npm info @sap/hana-client

The following commands can be used to view the latest available version of a package, remove a package, add a specific version of a package and then update it to the latest version.

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npm view @sap/hana-client version
npm uninstall @sap/hana-client
npm install @sap/hana-client@2.12.25
npm list @sap/hana-client
npm update @sap/hana-client
npm list @sap/hana-client

1. Open a file named nodeQuery.js in an editor.

   Shell (Microsoft Windows)

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   notepad nodeQuery.js
   

   Substitute pico below for your preferred text editor.

   Shell (Linux or Mac)

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   pico nodeQuery.js
   

2. Add the code below to nodeQuery.js. Note that the values for host, port, user name and password are provided by the previously configured hdbuserstore key USER1UserKey.

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   'use strict';
   const { PerformanceObserver, performance } = require('perf_hooks');
   var util = require('util');
   var hana = require('@sap/hana-client');
   
   var connOptions = {
       //Option 1, retrieve the connection parameters from the hdbuserstore
       serverNode: '@USER1UserKey',  //host, port, uid, and pwd retrieved from hdbuserstore
   
       //Option 2, specify the connection parameters
       //serverNode: 'host:port',
       //UID: 'USER1',
       //PWD: 'Password1',
   
       //Additional parameters
       //As of 2.7 trace info can be directed to stdout or stderr
       //traceFile: 'stdout',
       //traceOptions: 'sql=warning',
   
       //As of SAP HANA Client 2.6, connections on port 443 enable encryption by default (HANA Cloud).
       //encrypt: 'true',  //Must be set to true when connecting to HANA as a Service
       sslValidateCertificate: 'false',  //Must be set to false when connecting to an SAP HANA, express edition instance that uses a self-signed certificate.
   
       //For encrypted connections, the default crypto provider is mscrypto on Windows or openSSL on Linux or macos
       //To use the SAP crypto provider, uncomment the below line.
       //sslCryptoProvider: 'commoncrypto',
   
       //As of SAP HANA Client 2.6 for OpenSSL connections, the following settings can be ignored as root certificates are read from the default OS location.
       //ssltruststore: '/home/dan/.ssl/trust.pem', //Used to specify where the trust store is located
       //Alternatively provide the contents of the certificate directly (DigiCertGlobalRootCA.pem)
       //DigiCert Global Root CA: https://cacerts.digicert.com/DigiCertGlobalRootCA.crt.pem used for SAP HANA cloud
       //on-premise cert can be retrieved using openssl s_client -connect localhost:39015
       //This option is not supported with the mscrypto provider (the default provider on Windows)
       //ssltruststore: '-----BEGIN CERTIFICATE-----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-----END CERTIFICATE-----'
   };
   
   //Synchronous  example querying a table
   var connection = hana.createConnection();
   
   //As of 2.9, tracing can be directed to a callback
   /*
   var traceCB = function (buf) {
       console.log(buf);
   };
   connection.onTrace("sql=error,api=debug,OutBufferSize=64k", traceCB);  
   */
   
   connection.connect(connOptions);
   
   //connection.onTrace("", null);  //disables callback tracing for the rest of the program
   
   var sql = 'select TITLE, FIRSTNAME, NAME from HOTEL.CUSTOMER;';
   var t0 = performance.now()
   var result = connection.exec(sql);
   console.log(util.inspect(result, { colors: false }));
   var t1 = performance.now();
   console.log("time in ms " +  (t1 - t0));
   connection.disconnect();
   

3. Run the app.

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   node nodeQuery.js
   

   

   Note the above app makes use of some of the SAP HANA client Node.js driver methods, such as connect, exec and disconnect.

   Notice in the documentation that the above methods support being called in a synchronous or asynchronous manner. Two examples showing the drivers methods being used asynchronously are shown in the next two steps.

   To enable debug logging of the SAP HANA Node.js client, enter the following command and then rerun the app.

   Shell (Microsoft Windows)

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   set DEBUG=*
   node nodeQuery.js
   

   Shell (Linux or Mac)

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   export DEBUG=*
   node nodeQuery.js
   

   

   The value of the environment variable DEBUG can be seen and removed with the commands below.

   Shell (Microsoft Windows)

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   set DEBUG
   set DEBUG=
   set DEBUG
   

   Shell (Linux or Mac)

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   printenv | grep DEBUG
   unset DEBUG
   printenv | grep DEBUG
   

Connection pooling can improve performance when making multiple, brief connections to the SAP HANA database. The following sample makes two connections one after another without using a connection pool and then using a connection pool. It demonstrates how the time taken to make a connection with a connection retrieved from a pool is significantly shorter.

1. Open a file named nodeQueryConnectionPool.js in an editor.

   Shell (Microsoft Windows)

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   notepad nodeQueryConnectionPool.js
   

   Substitute pico below for your preferred text editor.

   Shell (Linux or Mac)

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   pico nodeQueryConnectionPool.js
   

2. Add the code below to nodeQueryConnectionPool.js. Note that the values for host, port, user name and password are provided by the previously configured hdbuserstore key USER1UserKey.

   JavaScript

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   'use strict';
   const { PerformanceObserver, performance } = require('perf_hooks');
   var util = require('util');
   var hana = require('@sap/hana-client');
   
   var connOptions = {
       //Option 1, retrieve the connection parameters from the hdbuserstore
       serverNode: '@USER1UserKey'  //host, port, uid, and pwd retrieved from hdbuserstore
   
       //Option 2, specify the connection parameters
       //serverNode: 'host:port',
       //UID: 'USER1',
       //PWD: 'Password1',
   };
   
   var poolProperties = {
       poolCapacity: 10,  //max # of connections in the pool waiting to be used
       maxConnectedOrPooled: 20, //max # of connections in the pool + the # of connections in use
       pingCheck: false,
       maxPooledIdleTime: 3600, //1 hour (in seconds)
   }
   
   var pool = null;
   
   queryTable(false, "1st Run");
   queryTable(false, "2nd Run");
   queryTable(true, "1st Run");
   //console.log(pool.clear());
   queryTable(true, "2nd Run");
   console.log("Connections in use :" + pool.getInUseCount());
   console.log("Connections in the pool :" + pool.getPooledCount());
   
   //Creates two connections either using connection pooling or not
   //Displays timing information
   function queryTable(usePool, run) {
       var t0 = performance.now()
       var connection = null;
       if (!usePool) {
           connection = hana.createConnection();
           connection.connect(connOptions);
           var t1 = performance.now();
       }
       else {
           var t0 = performance.now();
           if (pool === null) {
               pool = hana.createPool(connOptions, poolProperties); //create a connection pool
           }
   
           connection = pool.getConnection(); //get a connection from the pool
           var t1 = performance.now();
       }
   
       var t2 = performance.now();
       var sql = 'select TITLE, FIRSTNAME, NAME from HOTEL.CUSTOMER;';
       var result = connection.exec(sql);
       var t3 = performance.now();
   
       var t4 = performance.now();
       //console.log(util.inspect(result, { colors: false }));
       var t5 = performance.now();
   
       var t6 = performance.now();
       connection.disconnect(); //returns connection to the pool
       var t7 = performance.now();
   
       console.log("Connection Pool Enabled: " + usePool + " " + run);
       console.log("=====================================");
       console.log("Connection time in ms: " +  (t1 - t0));
       console.log("Query time in ms        " +  (t3 - t2));
       console.log("Display time in ms:     " +  (t5 - t4));
       console.log("Disconnect time in ms:   " +  (t7 - t6));
       console.log("Total time in ms:      " +  (t7 - t0) + "\n");
   }
   

3. Run the app.

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   node nodeQueryConnectionPool.js
   

   

   See Node.js Connection Pooling for additional details. The example above uses a new API that was added in the 2.13 release and documented in the 2.14 release. This new API provides a more direct way to interact with the connection pool.

Asynchronous programming enables non-blocking code execution which is demonstrated in the below example.

1. Open a file named nodeQueryCallback.js in an editor.

   Shell (Microsoft Windows)

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   notepad nodeQueryCallback.js
   

   Substitute pico below for your preferred text editor.

   Shell (Linux or Mac)

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   pico nodeQueryCallback.js
   

2. Add the code below to nodeQueryCallback.js. Note that the values for host, port, user name and password are provided by the previously configured hdbuserstore key USER1UserKey.

   JavaScript

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   'use strict';
   var util = require('util');
   var hana = require('@sap/hana-client');
   
   var connOptions = {
       //Option 1, retrieve the connection parameters from the hdbuserstore
       serverNode: '@USER1UserKey',  //host, port, uid, and pwd retrieved from hdbuserstore
   
       //Option 2, specify the connection parameters
       //serverNode: 'host:port',
       //UID: 'USER1',
       //PWD: 'Password1',
   
       sslValidateCertificate: 'false',  //Must be set to false when connecting to an SAP HANA, express edition instance that uses a self-signed certificate.
   };
   
   //Asynchronous example calling a stored procedure with callbacks
   var connection = hana.createConnection();
   
   connection.connect(connOptions, function(err) {
       if (err) {
           return console.error(err);
       }
       //Prepared statement example
       const statement = connection.prepare('CALL HOTEL.SHOW_RESERVATIONS(?,?)');
       const parameters = [11, '2020-12-24'];
       var results = statement.execQuery(parameters, function(err, results) {
           if (err) {
               return console.error(err);
           }
           processResults(results, function(err) {
               if (err) {
                   return console.error(err);
               }
               results.close(function(err) {
                   if (err) {
                       return console.error(err);
                   }
                   statement.drop(function(err) {
                       if (err) {
                           return console.error(err);
                       }
                       return connection.disconnect(function(err) {
                           if (err) {
                               return console.error(err);
                           }
                       });
                   });
               });
           });
       });
   });
   
   function processResults(results, cb) {
       results.next(function (err, hasValues) {
           if (err) {
               return console.error(err);
           }
           if (hasValues) {
               results.getValues(function (err, row) {
                   console.log(util.inspect(row, { colors: false }));
                   processResults(results, cb);
               });
           }
           else {
               return cb();
           }
       });
   }
   

3. Run the app.

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   node nodeQueryCallback.js
   

   

   Notice that asynchronous method calls use callback functions.

The Node.js driver for the SAP HANA client added support for promises in the 2.11 release. The following example demonstrates this. Notice that there is less nesting of code then the previous example.

1. Open a file named nodeQueryPromise.js in an editor.

   Shell (Microsoft Windows)

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   notepad nodeQueryPromise.js
   

   Substitute pico below for your preferred text editor.

   Shell (Linux or Mac)

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   pico nodeQueryPromise.js
   

2. Add the code below to nodeQueryPromise.js. Note that the values for host, port, user name and password are provided by the previously configured hdbuserstore key USER1UserKey.

   JavaScript

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   'use strict';
   var util = require('util');
   var hana = require('@sap/hana-client');
   var PromiseModule = require('@sap/hana-client/extension/Promise.js');
   
   var connOptions = {
       //Option 1, retrieve the connection parameters from the hdbuserstore
       serverNode: '@USER1UserKey',  //host, port, uid, and pwd retrieved from hdbuserstore
   
       //Option 2, specify the connection parameters
       //serverNode: 'host:port',
       //UID: 'USER1',
       //PWD: 'Password1',
   
       sslValidateCertificate: 'false',  //Must be set to false when connecting to an SAP HANA, express edition instance that uses a self-signed certificate.
   };
   
   //Asynchronous example calling a stored procedure that uses the promise module
   var connection = hana.createConnection();
   var statement;
   
   PromiseModule.connect(connection, connOptions)
       .then(() => {
            //Prepared statement example
            return PromiseModule.prepare(connection, 'CALL HOTEL.SHOW_RESERVATIONS(?,?)');
       })
       .then((stmt) => {
           statement = stmt;
           const parameters = [11, '2020-12-24'];
           return PromiseModule.executeQuery(stmt, parameters);
       })
       .then((results) => {
           return processResults(results);
       })
       .then((results) => {
           return PromiseModule.close(results);
       })
       .then(() => {
           PromiseModule.drop(statement);
       })
       .then(() => {
           PromiseModule.disconnect(connection);
       })
       .catch(err =>  {
           console.error(err);
       });
   
   function processResults(results) {
       return new Promise((resolve, reject) => {
       var done = false;
           PromiseModule.next(results)
               .then((hasValues) => {
                   if (hasValues) {
                       return PromiseModule.getValues(results);
                   }
                   else {
                       done = true;
                   }
               })
               .then((values) => {
                   if (done) {
                       resolve(results);
                   }
                   else {
                       console.log(util.inspect(values, { colors: false }));
                       return processResults(results);
                   }
               })
               .catch (err => {
                   reject(err);
               });
       })
   }
   

3. Run the app.

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   node nodeQueryPromise.js
   

   

   The above code makes use of the promise module. Additional details on promises can be found at Using Promises.

Visual Studio Code can run and debug a Node.js application. It is a lightweight but powerful source code editor which is available on Windows, macOS and Linux.

1. If required, download Visual Studio Code..

2. In Visual Studio Code, choose File | Add Folder to Workspace and then add the HANAClientsTutorial folder.

   

3. Open the file nodeQuery.js.

4. Place a breakpoint inside the connection.exec callback. Select Run | Start Debugging | Node.js.

   Notice that the debug view becomes active.

   Notice that the program stops running at the breakpoint that was set. Observe the variable values in the leftmost pane. Step through code.

   

Congratulations! You have created and debugged a Node.js application that connects to and queries an SAP HANA database.