Extracting json data from an OData API gives inconsistent results?

I'm attempting to extract data from the Wales government statistics services OData API. Details on the API can be found here, including an example of how to filter the data.

However I seem to be getting a non-deterministic subset of the data i.e. each attempt results in a different number of records returned.

Below is a simple reproducible example.

Additionally I have also tried (HT @martinjhnhadley):

  • using RJSONIO::fromJSON(), which has the same result.
  • attempting to use the odata.nextLink url, if it is returned in the json object, to keep extracting more data. Again, each attempt results in a different sized object.

Any insight will be much appreciated!

## preliminaries

# prepare filters
filter1 <- "Column_ItemName_ENG"
filter1.value <- "Gross%20expenditure"
filter2 <- "Row_ItemName_ENG"
filter2.value <- "Parking%20of%20vehicles"

query <- paste0("http://open.statswales.gov.wales/en-gb/dataset/lgfs0009?$filter=",
                filter1, "%20eq%20%27", filter1.value, "%27%20and%20",
                filter2, "%20eq%20%27", filter2.value, "%27")

# test 1
test1 <- jsonlite::fromJSON(query)
test1 <- test1[[2]]

# test 2
test2 <- jsonlite::fromJSON(query)
test2 <- test2[[2]]

# test 3
test3 <- jsonlite::fromJSON(query)
test3 <- test3[[2]]

# compare results

PS: I have cross-posted this question to Stackoverflow, and I promise to update either post with relevant solutions found on the other one.

1 Like

This topic was automatically closed 21 days after the last reply. New replies are no longer allowed.

If you have a query related to it or one of the replies, start a new topic and refer back with a link.