Bridge CSV Connectivity with Apache NiFi

Apache NiFi supports powerful and scalable directed graphs of data routing, transformation, and system mediation logic. When paired with the CData JDBC Driver for CSV, NiFi can work with live CSV data. This article describes how to connect to and query CSV data from an Apache NiFi Flow.

With built-in optimized data processing, the CData JDBC driver offers unmatched performance for interacting with live CSV data. When you issue complex SQL queries to CSV, the driver pushes supported SQL operations, like filters and aggregations, directly to CSV and utilizes the embedded SQL engine to process unsupported operations client-side (often SQL functions and JOIN operations). Its built-in dynamic metadata querying allows you to work with and analyze CSV data using native data types.

Connecting to CSV Data in Apache NiFi

1. Download the CData JDBC Driver for CSV installer, unzip the package, run the .exe file to install the driver.

2. Copy the CData JDBC Driver JAR file (and license file if it exists), cdata.jdbc.csv.jar (and cdata.jdbc.csv.lic), to the Apache NiFi lib subfolder, for example, C:\nifi-1.3.0-bin\nifi-1.3.0\lib.

   On Windows, the default location for the CData JDBC Driver is C:\Program Files\CData\CData JDBC Driver for CSV.

3. Start Apache NiFi by running the run-nifi.bat file in bin subfolder, for example, C:\nifi-1.3.0-bin\nifi-1.3.0\bin.

   (OR)

   Use the command prompt to navigate to the particular directory and run the run-nifi.bat file for example:

   cd C:\nifi-1.3.0-bin\nifi-1.3.0\bin
   .\run-nifi.bat
   

4. Navigate to the Apache NiFi UI in your web browser: It should be https://localhost:8443/nifi.

   Note: If users are utilizing an older version of Apache NiFi, they should access it via http://localhost:8080/nifi. In earlier versions, HTTP was the protocol employed. However, in the most recent version, HTTPS is the standard. By default, HTTP operates on port 8080, while HTTPS uses port 8443.

5. When accessing Apache NiFi via a URL, it prompts you to enter a username and password for login.

   

   To retrieve login credentials, users should consult the 'App.log' file located within the log directory of their NiFi installation. This file typically contains the necessary details for accessing the NiFi interface.

   
6. Right-click on the Nifi Flow's workspace and click "Controller Services"
7. Click the button to create a new controller service.
8. In the Controller Services section, location the newly created "DBCPConnection Pool" and click the menu () >> Edit to configure the new connection.

9. Fill in the properties:

   • Database Connection URL: jdbc:csv:URI=/PATH/TO/MyCSVFilesFolder;
   • Database Driver Class Name: cdata.jdbc.csv.CSVDriver
   • Database Driver Location(s): Path to your Apache NiFi's lib folder where the JAR files are present.

   Built-in Connection String Designer

   For assistance in constructing the JDBC URL, use the connection string designer built into the CSV JDBC Driver. Either double-click the JAR file or execute the JAR file from the command-line.

   
   java -jar cdata.jdbc.csv.jar
   

   Fill in the connection properties and copy the connection string to the clipboard.

   Connecting to Local or Cloud-Stored (Box, Google Drive, Amazon S3, SharePoint) CSV Files

   CData Drivers let you work with CSV files stored locally and stored in cloud storage services like Box, Amazon S3, Google Drive, or SharePoint, right where they are.

   Setting connection properties for local files

   Set the URI property to local folder path.

   Setting connection properties for files stored in Amazon S3

   To connect to CSV file(s) within Amazon S3, set the URI property to the URI of the Bucket and Folder where the intended CSV files exist. In addition, at least set these properties:

   • AWSAccessKey: AWS Access Key (username)
   • AWSSecretKey: AWS Secret Key

   Setting connection properties for files stored in Box

   To connect to CSV file(s) within Box, set the URI property to the URI of the folder that includes the intended CSV file(s). Use the OAuth authentication method to connect to Box.

   Dropbox

   To connect to CSV file(s) within Dropbox, set the URI proprerty to the URI of the folder that includes the intended CSV file(s). Use the OAuth authentication method to connect to Dropbox. Either User Account or Service Account can be used to authenticate.

   SharePoint Online (SOAP)

   To connect to CSV file(s) within SharePoint with SOAP Schema, set the URI proprerty to the URI of the document library that includes the intended CSV file. Set User, Password, and StorageBaseURL.

   SharePoint Online REST

   To connect to CSV file(s) within SharePoint with REST Schema, set the URI proprerty to the URI of the document library that includes the intended CSV file. StorageBaseURL is optional. If not set, the driver will use the root drive. OAuth is used to authenticate.

   Google Drive

   To connect to CSV file(s) within Google Drive, set the URI property to the URI of the folder that includes the intended CSV file(s). Use the OAuth authentication method to connect and set InitiateOAuth to GETANDREFRESH.

   
10. In the Controller Services section, locate the newly created DBCPConnection Pool and click the menu () >> Enable to enable the new connection.
11. In the "Enable Controller Service" window, set Scope to "Service and referencing components"
12. To establish a connection and execute a select query, simply drag and drop the processor (indicated by the yellow highlight) into the workspace.
13. Select the 'ExecuteSQL' processor and click the 'Add' button to make it visible in the workspace.
14. Double-click on the added processor (ExecuteSQL)to open the connection page.
15. In the Properties section, fill in the required information. Make sure to set the Database Connection Pooling Service to match the DBCPConnectionPool that you have created, and set your desired SQL query that you want to get executed in the SQL select query section.
16. Go to Relationships and make sure to select an option on how the component should proceed in case of success and failure of the execution process.
17. You can enable the ExecuteSQL component by either selecting it and clicking Enable on the Operation section, or by right-clicking it and selecting Enable.

Your CSV data is now available for use in Apache NiFi. For example, you can use the DBCPConnection Pool as the source for a QueryDatabaseTable processor (shown below).

Download a free, 30-day trial of the CData JDBC Driver for CSV and start working with your live CSV data in Apache NiFi. Reach out to our Support Team if you have any questions.