Document default database name in the RMySQL::mysqlHasDefault() function

[paulrougieux]

This RMySQL package is being phased out, but the RMySQL::mysqlHasDefault() function is not present in the new RMariaDB.

I have spent some time figuring out how to setup a test database for testthat and I just wanted to specify that the default database used by RMySQL::mysqlHasDefault() has to be called "test". Other database names return an error Could not initialise default MySQL database.

Here is how I created the test database :

$ mysql -u root -p

Then give the following mysql commands:

mysql> create database test;
mysql> connect test;
mysql> grant all privileges on * . * to R@localhost;

And the configuration in ~/.my.cnf

#    [rs-dbi]
#    user = R
#    password = ***
#    host = localhost
#    database = test

Then RMySQL::mysqlHasDefault() returns TRUE.