CouchDB offset is 1 but query returns empty

Question

I'm testing CouchDB v2.3.1 and I'm having trouble understanding a particular result.

This is current db state filtered by a custom view:

curl 'http://127.0.0.1:5984/music/_design/albums/_view/_by_name' | json_pp
{
   "offset" : 0,
   "total_rows" : 3,
   "rows" : [
      {
         "id" : "42dc72485892b5de28807f28130016c6",
         "value" : {
            "by" : "The Beatles",
            "album" : {
               "title" : "Abbey Road",
               "year" : 1969
            }
         },
         "key" : "Abbey Road"
      },
      {
         "value" : {
            "album" : {
               "year" : 1965,
               "title" : "Help!"
            },
            "by" : "The Beatles"
         },
         "key" : "Help!",
         "id" : "42dc72485892b5de28807f28130016c6"
      },
      {
         "id" : "42dc72485892b5de28807f28130016c6",
         "value" : {
            "by" : "The Beatles",
            "album" : {
               "title" : "Sgt. P",
               "year" : 1967
            }
         },
         "key" : "SGt. P"
      }
   ]
}

As you can see, I have 3 rows(Beatle albums), who´s keys are album names.

Now the following query return an offset of 1. As you can see above, there is no row that has a key with name "Hel!". Notice that I'm filtering the query with the key="Hel!" query param

curl 'http://127.0.0.1:5984/music/_design/albums/_view/_by_name?key="Hel!"' | json_pp
{
   "offset" : 1,
   "total_rows" : 3,
   "rows" : []
}

Now the following query return an offset of 2. As you can see above, there is no row that has a key with name "No-such-namea!".

curl 'http://127.0.0.1:5984/music/_design/albums/_view/_by_name?key="No-such-namea"' | json_pp
    {
   "rows" : [],
   "total_rows" : 3,
   "offset" : 2
}

From this answer:

The offset is the index in the view of the first matching row for the given query

I understand that, if there is a match, the offset should be the index on the unfiltered view, of the first match from the rows returned.

Therefore, I'm not understanding why the offset is not 0 in the two previous examples.

Thank you for your time.

The linked answer https://stackoverflow.com/a/34811501/2358409 also states: "If there are no entries in the view for a direct key query, the offset value is the index into the view where the entry would be if it had the desired key." — uminder, Sep 19 '19 at 05:11

score 0 · Answer 1 · answered Sep 19 '19 at 16:57

0

Uminder made me notice the answer is given in same link I provided.

"If there are no entries in the view for a direct key query, the offset value is the index into the view where the entry would be if it had the desired key."

answered Sep 19 '19 at 16:57

Emilio Basualdo Cibils

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CouchDB offset is 1 but query returns empty

1 Answers1