Query Solr via R

Though it’s possible to query Solr directly through its HTTP API, we typically run our queries through R, for two main reasons:

1. The result is returned in a more useful way to R without extra work on your part
2. We can more easily pass our authentication token with the query

Why does #2 matter? Well by default, all of those URLs above only return publicly-readable Solr documents. If a private document matches any of those queries, Solr won’t tell you that. It will act like the non-public-readable documents don’t exist. So we must pass an authentication token to access non-public-readable content. This bit is crucial for working with the ADC, so you’ll very often want to use R instead of visiting those URLs in a web browser.

cn <- CNode("PROD")
adc <- getMNode(cn, "urn:node:ARCTIC")
# Set your token if you need/want!

#string your parameters together like this: dataone::query(mn, "q=title:*soil*&fl=title&rows=10")
#or alternatively, list them out:
query(adc, list(q="title:*soil*",
                fl="title",
                rows="10"))

By default, query returns the result as a list, but a data.frame can be a more useful way to work with the result. To get a data.frame instead, just set the as argument to ‘data.frame’ to get a data.frame:

query(adc, list(q="title:*soil*",
                fl="title",
                rows="10"),
      as = "data.frame")