Analyze FTP Data in R

Access FTP data with pure R script and standard SQL on any machine where R and Java can be installed. You can use the CData JDBC Driver for FTP and the RJDBC package to work with remote FTP data in R. By using the CData Driver, you are leveraging a driver written for industry-proven standards to access your data in the popular, open-source R language. This article shows how to use the driver to execute SQL queries to FTP and visualize FTP data by calling standard R functions.

Install R

You can match the driver's performance gains from multi-threading and managed code by running the multithreaded Microsoft R Open or by running open R linked with the BLAS/LAPACK libraries. This article uses Microsoft R Open 3.2.3, which is preconfigured to install packages from the Jan. 1, 2016 snapshot of the CRAN repository. This snapshot ensures reproducibility.

Load the RJDBC Package

To use the driver, download the RJDBC package. After installing the RJDBC package, the following line loads the package:

Connect to FTP as a JDBC Data Source

You will need the following information to connect to FTP as a JDBC data source:

• Driver Class: Set this to cdata.jdbc.ftp.FTPDriver
• Classpath: Set this to the location of the driver JAR. By default this is the lib subfolder of the installation folder.

The DBI functions, such as dbConnect and dbSendQuery, provide a unified interface for writing data access code in R. Use the following line to initialize a DBI driver that can make JDBC requests to the CData JDBC Driver for FTP:

You can now use DBI functions to connect to FTP and execute SQL queries. Initialize the JDBC connection with the dbConnect function.

To connect to FTP or SFTP servers, specify at least RemoteHost and FileProtocol. Specify the port with RemotePort.

Set User and Password to perform Basic authentication. Set SSHAuthMode to use SSH authentication. See the Getting Started section of the data provider help documentation for more information on authenticating via SSH.

Set SSLMode and SSLServerCert to secure connections with SSL.

The data provider lists the tables based on the available folders in your FTP server. Set the following connection properties to control the relational view of the file system:

• RemotePath: Set this to the current working directory.
• TableDepth: Set this to control the depth of folders to list as views.
• FileRetrievalDepth: Set this to retrieve and list files recursively from the root table.

Stored Procedures are available to download files, upload files, and send protocol commands. See the Data Model chapter of the FTP data provider documentation for more information.

Built-in Connection String Designer

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

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

Below is a sample dbConnect call, including a typical JDBC connection string:

Schema Discovery

The driver models FTP APIs as relational tables, views, and stored procedures. Use the following line to retrieve the list of tables:

Execute SQL Queries

You can use the dbGetQuery function to execute any SQL query supported by the FTP API:

You can view the results in a data viewer window with the following command:

Plot FTP Data

You can now analyze FTP data with any of the data visualization packages available in the CRAN repository. You can create simple bar plots with the built-in bar plot function: