downloading data from OECD website using the OECD package in R - r

Question

I am trying to download data directly from the OECD website using the OECD package in R. I'm specifically trying to download data from the industrial production dataset (https://data.oecd.org/industry/industrial-production.htm) for South Africa. I believe that the codes for the dataset itself and for South Africa are MEI_REAL and ZAF.
However, when I try to run the following
df <- get_dataset("MEI_REAL",
filter = 'ZAF',
start_time = 2019, end_time = 2020)
I get the following error
Error in rsdmx::readSDMX(url) :
HTTP request failed with status: 400 Bad Request
Can anyone advise on what I'm doing wrong? I've never used this package before so I'm struggling to figure it out.
TIA

Answer 1

To actually use the filter it has to be something like
df <- get_dataset("MEI_REAL",
filter = list(c(),'ZAF'),
start_time = 2019, end_time = 2020)
as the country codes are in the second column, but I don't know how you can know this in advance without just downloading the whole dataset first (just drop the filter argument entirely to do that).

Answer 2

The code in the question fails because LOCATION is the second column in the data frame, and the filter = statement does not account for this. We can fix the request by adding NULL to the list() passed to filter= argument.
library(OECD)
# filter on second column
saProduction <- get_dataset("MEI_REAL",
filter = list(NULL,"ZAF"),
start_time = 2019,
end_time = 2020)
head(saProduction)
...and the output:
> head(saProduction)
SUBJECT LOCATION FREQUENCY TIME_FORMAT UNIT POWERCODE REFERENCEPERIOD obsTime
1 PRMNTO01 ZAF A P1Y IDX 0 2015_100 2019
2 PRMNTO01 ZAF Q P3M IDX 0 2015_100 2019-Q1
3 PRMNTO01 ZAF Q P3M IDX 0 2015_100 2019-Q2
4 PRMNTO01 ZAF Q P3M IDX 0 2015_100 2019-Q3
5 PRMNTO01 ZAF Q P3M IDX 0 2015_100 2019-Q4
6 PRMNTO01 ZAF Q P3M IDX 0 2015_100 2020-Q1
obsValue
1 100.46670
2 100.97510
3 101.30840
4 100.04170
5 99.47495
6 97.40812
How did I figure out that the right entry into the list is NULL? When one looks at the arguments for get_dataset(), we see that NULL is a valid value for filter =, so I inferred that I could use it as a value in the filter list().

Answer 3

For anyone who ecnounters the same problem: My "solution" is to set the dataframe-ID you want at different positions in the filter. E.g:
1.try:
filter_GDP <- list("B1_GE")
GDP <- get_dataset("QNA", filter_GDP)
This gives back an error, hence i set the dataframe-ID at the next position in the filter list (by including NULL):
filter_GDP <- list(NULL, "B1_GE")
GDP <- get_dataset("QNA", filter_GDP)
This works, so now you can look up the positions of the other parameters you want to filter, in my case:
filter_GDP <- list(NULL,"B1_GE", "CQRSA", "Q")
GDP <- get_dataset("QNA", filter_GDP)