Over a million developers have joined DZone.
{{announcement.body}}
{{announcement.title}}

CouchDB: 'Badmatch' When Executing View

DZone's Guide to

CouchDB: 'Badmatch' When Executing View

· Database Zone
Free Resource

Read why times series is the fastest growing database category.

I’ve been playing around with CouchDB again in my annual attempt to capture the links appearing on my twitter stream and I managed to create the following error for myself:

$ curl http://127.0.0.1:5984/twitter_links/_design/cleanup/_view/find_broken_links
{"error":"badmatch","reason":"{\n   \"find_broken_links\": {\n       \"map\": \"function(doc) {   \nvar prefix = doc.actual_link.match(/.*/);      

It turns out this error is because I’ve managed to create new line characters in the view while editing it inside CouchDBX. D’oh!

A better way is to edit the view in a text editor and then send it to CouchDB using curl.

The proper way to update a view would be to add a ‘_rev’ property to the body of the JSON document but I find it annoying to go and edit the document so I’ve just been deleting and then recreating my views.

$ curl -X GET http://127.0.0.1:5984/twitter_links/_design/cleanup/
{"_id":"_design/cleanup","_rev":"1-8be14d29f183b61f1ade160badef3f75","views"...}
$ curl -X DELETE http://127.0.0.1:5984/twitter_links/_design/cleanup?rev=1-8be14d29f183b61f1ade160badef3f75
{"ok":true,"id":"_design/cleanup","rev":"2-9fa15c1fdbb7cbaa659d623bc897b9da"}
$ curl -X PUT http://127.0.0.1:5984/twitter_links/_design/cleanup -d @cleanup.json
{"ok":true,"id":"_design/cleanup","rev":"17-b0763381b79f3fda843f57a7dcc842e1"}

I guess there’s probably a library somewhere which would encapsulate all that for me but I’m just hacking around at the moment.

It’s interesting to to see how you interact differently with a document database compared to what you’d do with a relational one with respect to optimistic concurrency.

Learn how to get 20x more performance than Elastic by moving to a Time Series database.

Topics:

Published at DZone with permission of Mark Needham, DZone MVB. See the original article here.

Opinions expressed by DZone contributors are their own.

{{ parent.title || parent.header.title}}

{{ parent.tldr }}

{{ parent.urlSource.name }}