How to connect R to MySQL? Failed to connect to database: Error: Plugin caching_sha2_password could not be loaded

Question

I recently installed MySQL on my computer and am trying to connect RStudio to MySQL. I followed instructions in a book as well as instructions here. However, whenever I use dbConnect() or src_mysql in RStudio, I get this error message:

Error in .local(drv, ...) : 
  Failed to connect to database: Error: Plugin caching_sha2_password could not be loaded: The specified module could not be found

For example, I might login to MySQL using the command prompt in Windows

mysql -u username -p

and create a database as follows

CREATE DATABASE myDatabase;

and then in RStudio:

library(RMySQL)
db <- dbConnect(MySQL(), dbname = "myDatabase", user = "username", 
           password = "password", host = "localhost")

and my response is always that error message listed above.

And if you need it: sessionInfo()

R version 3.5.2 (2018-12-20)
Platform: x86_64-w64-mingw32/x64 (64-bit)
Running under: Windows >= 8 x64 (build 9200)

Answer 1

The R mysql library depends on libmysqlclient/libmariadbclient. The missing caching_sha2_password seems to be an indicator that an old mysqlclient version or a libmariadbclient isn't installed. Only very recently did caching_sha2_password get added to mariadb (3.0.8)

An alternative, like this answer, is to change the user in mysql to use a different authentication mechanism:

You set the user back to mysql_native_password:

ALTER USER 'username'@'localhost'
IDENTIFIED WITH mysql_native_password BY 'password'

To make this the default for all newly created users change the my.cnf/my.ini setting default_authentication_plugin=mysql_native_password