CODEWITHSUNDEEP
pythonrethinkdb
Desprit
Desprit

Reputation: 716

RethinkDB, query with map and filter

I have rethinkdb 'competition' table. At the second level I got runners and each runner have a list of results:

"total_results": {
  "433915": [  #runner_id
    {
      "judge": "15561671",
      "result": 5,
      "round": "1"
    },
    {
      "judge": "08136a59",
      "result": 4,
      "round": "1"
    }
  ]
}

I do rethinkdb query:

results = (r.table('competitions').filter(lambda c: c['unique_id'] == competition_id)
    .map(lambda c: c['total_results'])
    .map(lambda t: t[runner_id])
.run(conn))

This piece of code works fine. Now I want to apply filter based on 'round' value. I add it right after the second .map() so results query looks like:

results = (r.table('competitions').filter(lambda c: c['unique_id'] == competition_id)
    .map(lambda c: c['total_results'])
    .map(lambda t: t[runner_id])
    .filter(lambda x: x['round'] == round)
.run(conn))

But I'm getting empty list. And this is strange for me because if I move .filter() outside of rethinkdb query and do it like:

by_round = filter(lambda x: x['round'] == round, results)

I get results. There should be something I'm doing wrong in rethink query... Can you give me a tip please?

p.s. I have thousands results in the database. There should be dozens results based on my query params.

Upvotes: 1

Views: 256

Answers (1)

mlucy
mlucy

Reputation: 5289

I think you want your second map to be a concat_map. (Alternatively, if you like the existing output format, you can put the filter inside a map like .map(lambda x: x.filter(...)).)

Upvotes: 1

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