R Client Library

By using the RJDBC library in R, R programs can access data from TDengine. Below are the installation process, configuration steps, and R code examples.

Installation Process

Before you start, ensure that you have the R language environment installed. Then follow these steps to install and configure the RJDBC library:

1. Install the Java Development Kit (JDK): The RJDBC library requires a Java environment. Please download the appropriate JDK for your operating system from the Oracle official website and follow the installation guide.

2. Install the RJDBC library: Execute the following command in the R console to install the RJDBC library.

   install.packages("RJDBC", repos='http://cran.us.r-project.org')
   note

   1. The R language software version 4.2 that comes with Ubuntu may produce a non-responsive bug when calling the RJDBC library. Please install the R language package from the official R website.
   2. Installing the RJDBC package on Linux may require installing additional components. For example, on Ubuntu, execute the command apt install -y libbz2-dev libpcre2-dev libicu-dev to install.
   3. On Windows systems, you need to set the JAVA_HOME environment variable.

3. Download the TDengine JDBC driver: Visit maven.org to download the TDengine JDBC driver (taos-jdbcdriver-X.X.X-dist.jar).

4. Place the TDengine JDBC driver in an appropriate location: Choose a suitable location on your computer to save the TDengine JDBC driver file (taos-jdbcdriver-X.X.X-dist.jar).

Configuration Process

After completing the installation steps, you need to configure some settings so that the RJDBC library can correctly connect to and access the TDengine time-series database.

1. Load the RJDBC and other necessary libraries in your R script:

   library(DBI)
   library(rJava)
   library(RJDBC)

2. Set the JDBC driver and JDBC URL:

   # Set the path to the JDBC driver (modify based on your actual storage location)
   driverPath <- "/path/to/taos-jdbcdriver-X.X.X-dist.jar"
   
   # Set the JDBC URL (modify based on your specific environment)
   url <- "jdbc:TAOS://localhost:6030/?user=root&password=taosdata"

3. Load the JDBC driver:

   # Load the JDBC driver
   drv <- JDBC("com.taosdata.jdbc.TSDBDriver", driverPath)

4. Create a TDengine database connection:

   # Create the database connection
   conn <- dbConnect(drv, url)

5. Once connected successfully, you can perform various database operations with the conn object, such as querying data, inserting data, etc.

6. Finally, don't forget to close the database connection when you're done using it:

   # Close the database connection
   dbDisconnect(conn)

R Language Example Code Using RJDBC

Here is an example code snippet that connects to the TDengine time-series database using the RJDBC library and executes a query:

Native Connection

library("DBI")
library("rJava")
library("RJDBC")

args<- commandArgs(trailingOnly = TRUE)
driver_path = args[1] # path to jdbc-driver for example: "/root/taos-jdbcdriver-3.2.4-dist.jar"
driver = JDBC("com.taosdata.jdbc.TSDBDriver", driver_path)
conn = dbConnect(driver, "jdbc:TAOS://127.0.0.1:6030/?user=root&password=taosdata")
dbGetQuery(conn, "SELECT server_version()")
dbSendUpdate(conn, "create database if not exists rtest")
dbSendUpdate(conn, "create table if not exists rtest.test (ts timestamp, current float, voltage int, devname varchar(20))")
dbSendUpdate(conn, "insert into rtest.test values (now, 1.2, 220, 'test')")
dbGetQuery(conn, "select * from rtest.test")
dbDisconnect(conn)

view source code

Please modify the JDBC driver, JDBC URL, username, password, and SQL query statement according to your actual TDengine time-series database environment and requirements.

By following the above steps and example code, you can access the TDengine time-series database using the RJDBC library in the R language environment for data querying and analysis operations.