I have indexed documents with a "MetadataFields" key whose values are json.
"MetadataFields": "{"continent":"north america","country":"united states","region":"x34","tagnumber":"abc-123"}
I'm able to search for a specific match in Search Explorer using
MetadataFields/tagnumber:abc-123
But I cannot figure out how to find documents where this attribute is null or missing. Is this possible? What is the proper syntax?
In Azure Cognitive Search, you can use filtering to find null items.
In Search Explorer, the syntax would look like this:
$filter=MetadataFields/tagnumber eq null
To do this, you would need to have the field tagnumber marked as filterable in your index definition.
Related
I am new to cloud-ant, In my current assignment i want to search all distinct records based on fields x:
I have documents which have domain as attribute. I want all unique domains which are present in my db.Below is the example,
documentNo1-{"domain":"gmail.com"}
documentNo2-{"domain":"ymail.com"}
documentNo3-{"domain":"gmail.com"}
expected result is API should return only unique domain name, like below
[gmail.com,ymail.com]
I am not getting operators in cloud-ant which can achieve this, only solution i have is to retrieve it and create our own unique domain list.
Looking for any good approach/solution for above scenario.
You can use Cloudant Search to create a faceted index.
See https://console.bluemix.net/docs/services/Cloudant/api/search.html#faceting
This would allow you to essentially group documents by domain, creating the unique list you need.
There is a good video tutorial showing this technique:
https://www.youtube.com/watch?v=9er3XI150VM
I searched everywhere for this but I can't find anything on that matter. If you don't predefine fields in MongoDB, couldn't a user with Insert permission then Insert a document with every kind of field he wants? Via Collection.insert? If I am thinking correctly here, is there a way to restrict this?
You can restrict inserting any kind of fields in these two ways:
Use collection.allow/deny(http://docs.meteor.com/#/full/allow) - the insert callback has a doc parameter, which contains the exact document that user wants to insert - you can check the content of it and deny the insertion if you spot fields that are not allowed.
Use SimpleSchema (https://github.com/aldeed/meteor-simple-schema) and Collection2 (https://github.com/aldeed/meteor-collection2) packages to define the schema and attach it to your collection - it will prevent the insertion if a document has additional/missing fields (or fields of not expected type).
This is my personal preference. Because fieldNames param in
Collections.update(userId, doc, fieldNames) only gives top-level fields in doc. So if you are having nested fields it is very hard to track.
So I don't use collection allow/deny rules. Without allow deny rules Collections.insert/Collections.update does nothing on client. Instead I am using Meteor methods to update/delete documents to collections, so I can decide which exact fields should update/insert.
(MongoDB Full Text Search)
Hello,
I have put some fields in index and this is how I could search for a search_keyword.
BasicDBObject search = new BasicDBObject("$search", "search_keyword");
BasicDBObject textSearch = new BasicDBObject("$text", search);
DBCursor cursor = users.find(textSearch);
I don't want search_keyword to be searched in all the fields specified in the index. *Is there any method to specify search_keyword to be searched in specific fields from the index??*
If so, please give me some idea how to do it in Java.
Thank you.
If you want to index a single field and search for it then it is the way it works by default. Lets say you want to index the field companyName. When you perform $text search on this collection, only the data from the companyName field will be used because you only included that field in your index.
Now the second scenario, your $text index includes more than one field. In this case you cannot limit the search to only look for values indexed from a specific field. The $text index is constructed on the collection level and a collection can have at most one $text index. Your option to limit search on specific field in this case may be to use regex instead.
MongoDB has the flexibility to fulfil requirements of other scenarios, but you can also evaluate using other technologies if your application is heavily search-driven and you are primarily after a full-text search engine for locating documents by keyword with a rich query syntax. ElasticSearch might be an alternative here. It really depends on the type of the application and your needs.
I'm toying with the Github search API (v3) and can't seem to find a description of the fields that are returned. Most of them are obvious, but there are a few like score that aren't. Does anyone know what score means, and does a field reference exist?
The score attribute is the search score of that document for a particular query, and is used for Best Match sorting. In other words, it's used for ranking search results, but it isn't shown in search results on github.com.
I'm trying to found a field defination like Solr's 'indexed but not stored'. http://sphinxsearch.com/wiki/doku.php?id=fields_and_attributes, by the document, sphinx has not defined such field. Is there anyway to reach this?
Fields ARE "indexed but not stored". They are the staple of full-text searching. A column is automatically a field unless made an attribute.
Attributes on the other hand, are stored - but not 'indexed' as such.