nosql

问题 Given the following example document of collection: { "timestamp": 1413543986, "message": "message", "readed": { "8": null, "9": null, "22": null }, "type": "1014574149174" } How do I update the value of specific key in object with key "readed"? For example update value for key "8": ... "8": 10, ... 回答1: You can use MERGE or MERGE_RECURSIVE as follows: db._query("FOR u IN test FILTER u._key == @key UPDATE u WITH 'read': MERGE_RECURSIVE(u.read, { '8': 10 }) } IN test", { key: "11611344050" })

问题 Given the following example document of collection: { "timestamp": 1413543986, "message": "message", "readed": { "8": null, "9": null, "22": null }, "type": "1014574149174" } How do I update the value of specific key in object with key "readed"? For example update value for key "8": ... "8": 10, ... 回答1: You can use MERGE or MERGE_RECURSIVE as follows: db._query("FOR u IN test FILTER u._key == @key UPDATE u WITH 'read': MERGE_RECURSIVE(u.read, { '8': 10 }) } IN test", { key: "11611344050" })

问题 I am inserting my data into MongoDB and had 240 such files. Instead of inserting everything into one big collection, I was thinking of inserting the files as a collection by themselves. Is this a good idea if I do a lot of queries on a commonly indexed column? If so, how can I initiate a query to query all the collections in my database? 回答1: Using an application server such as Solr can help you achieve what you want, also with the addition of fuzzy matching, synonyms, phonetic matching,

问题 Following this post from Neo4j's google group I have to say that I don't see any benefits when using this multiple-label-thing but rather, on the contrary, IMHO it just adds complexity for what a uniqueness constraint is. It could also tempt the user to introduce inheritance into the data model which would cause frustration since that's not possible at all... 回答1: Labels have not the notion of just representing a type, they are rather roles which are viable in different contexts. So in one

问题 I have got a Realm object class, and storing lots of data in there, imagine that I have a String uid; field. I want to get uid names, but on same uid names just only one time, For example uid AA AA BB CC DD BB BB I want to get just AA, BB, CC, DD. Only one time. I looked over realm documentation but couldn't find anything. Thanks for answers. 回答1: UPDATED : You can use distinct() to get distinct entries for an object class. // Returns the set of users that all have a different name

问题 I'm attempting to build a dynamic data-binding function called assemble which takes (2) input parameters: server response (JSON) - nested json object. instruction set (JSON) - a configuration object which controls the binding. The Problem: The function currently doesn't bind nested json. The Question: What do I need to change to make it able to support the desired output? The current output: <form class="myForm"> <div class="myFirstName">john</div> <div class="myLastName">doe</div> <div>john

问题 I have a MySQL DB View which is having a JOIN on 4 Tables and all indexes have been used properly and previously response time was fair enough but as the database is growing rapidly, the response time is gradually degrading , so how can we tune the performance ? I am new to solve this kind of complexity, Do I need to think about database mirroring or partitioning or NoSQl as well, if any doc can be supported on this, it would be very helpful in learning. 回答1: Depending on your retrieval/usage

问题 I'm working on a game (something like chess) where every move needs to be saved into a database per move. Since it's very important that both reads and writes are fast, and I don't need complex queries, I'm probably going to go with a NoSQL solution. Which one though? I'm thinking about MongoDB but will its durability be an issue? It's not the end of the world if some game movelists are corrupted, but would be problematic if it occurs too often. Suggestions? Thanks. 回答1: Last time I looked at

问题 I've been using mysql (with innodb; on Amazon rds) because it's sort of universal default, but it's been ridiculously under-performing, and tweaking it only delays the inevitable. The data is mostly relatively short (<1kB of bytes each) blobs information about 100Ms of urls. There is (or should be, mysql cannot seem to handle it) very high amount of insert / update / retrieve but few complex queries - not that complex queries wouldn't be useful, but because mysql is so slow that it's far

问题 I am trying to configure MongoDB database to Django. I tried a lot of tutorials but still, I am not able to configure. I followed following tutorials commands. http://2buntu.com/articles/1451/installing-django-and-mongodb-in-your-virtualenv/ http://django-mongodb-engine.readthedocs.org/en/latest/topics/setup.html http://docs.mongodb.org/manual/tutorial/write-a-tumblelog-application-with-django-mongodb-engine/ I added the following code to setting.py class. DATABASES = { 'default': { 'ENGINE'