Is there a (roughly) SQL or XQuery-like language for querying JSON? I’m thinking of very small datasets that map nicely to JSON where it would be nice to easily answer queries such as “what are all the values of X where Y > 3” or to do the usual SUM / COUNT type operations. As … Read more
Closed. This question is opinion-based. It is not currently accepting answers. Want to improve this question? Update the question so it can be answered with facts and citations by editing this post. Closed 8 years ago. Improve this question With all the hype, it seems really hard to find reliable information on when to use … Read more
I am not able to understand what Range / primary key is here in the docs on Working with Tables and Data in DynamoDB How does it work? What do they mean by “unordered hash index on the hash attribute and a sorted range index on the range attribute”? 4 Answers 4
Closed. This question is opinion-based. It is not currently accepting answers. Want to improve this question? Update the question so it can be answered with facts and citations by editing this post. Closed last year. Improve this question With the NoSQL movement growing based on document-based databases, I’ve looked at MongoDB lately. I have noticed … Read more
Are there any essential differences between CouchDB and Couchbase. 3 Answers 3
How can I add a new field to every document in an existent collection? I know how to update an existing document’s field but not how to add a new field to every document in a collection. How can I do this in the mongo shell? 7 Answers 7
PostgreSQL just introduced JSONB and it’s already trending on hacker news. How is it different from Hstore and JSON previously present in PostgreSQL? What are its advantages and limitations and when should someone consider using it? 9 Answers 9
Closed. This question needs to be more focused. It is not currently accepting answers. Closed 5 years ago. Locked. This question and its answers are locked because the question is off-topic but has historical significance. It is not currently accepting new answers or interactions. What I want is not a comparison between Redis and MongoDB. … Read more
I would like to execute a following query: db.mycollection.find(HAS IMAGE URL) What should be the correct syntax? 1Best Answer 11 This will return all documents with a key called “IMAGE URL”, but they may still have a null value. db.mycollection.find({“IMAGE URL”:{$exists:true}}); This will return all documents with both a key called “IMAGE URL” and a … Read more
I am stuck between these two NoSQL databases. In my project I will be creating a database within a database. For example, I need a solution to create dynamic tables. So users can create tables with columns and rows. I think either MongoDB or CouchDB will be good for this, but I am not sure … Read more
