I have the following entity in ElasticSearch:
{
"id": 123,
"entity-id": 1019,
"entity-name": "aaa",
"status": "New",
"creation-date": "2014-08-06",
"author": "bubu"
}
I try to query for all entities with status=New, so the above entity should appear there.
I run this code:
qesponse.setQuery(QueryBuilders.termQuery("status", "New"));
return qResponse.setFrom(start).setSize(size).execute().actionGet().toString();
But it return no result.
If I use this code (general search, not of specific field) I get the above entity.
qResponse.setQuery(QueryBuilders.queryString("New");
return qResponse.setFrom(start).setSize(size).execute().actionGet().toString();
Why?
The problem is a mismatch between a Term Query and using the Standard Analyzer when you index. The Standard Analyzer, among other things, lowercases the field when it's indexed:
Standard Analyzer
An analyzer of type standard is built using the Standard Tokenizer
with the Standard Token Filter, Lower Case Token Filter, and Stop
Token Filter.
http://www.elasticsearch.org/guide/en/elasticsearch/reference/current/analysis-standard-analyzer.html
The Term query, however, matches without analysis:
Term Query
Matches documents that have fields that contain a term (not analyzed).
The term query maps to Lucene TermQuery.
http://www.elasticsearch.org/guide/en/elasticsearch/reference/current/query-dsl-term-query.html
So in your case when you index the field status it becomes "new". But when you search with a Term Query it's looking for "New" - they don't match. They do match with a general search it works because the general search also uses the Standard Analyzer.
The default value of index for a string field is analyzed . So, when you write "status" = "New" , it will use standard_analyzer, and after analyzing it will write as "new" .
So, term Query doesn't seems to be working, If you wish to query like you specified ,write mapping for the field as "not_analyzed".
For more info. link
Related
I have a custom index for my products and I am using the Subset Analyzer. This Analyzer works great, but if you do field searches, it does not work.
For example, I have a document with the following fields:
"documentname", "My-Document-Name"
"tags", "1234,5678,9101"
"documentdescription", "This is a great Document, My-Document-Name."
When I just search "name AND tags:(1234)", I get this document in my results because it searches +_content:name.
-- However:
When I search "documentname:(name)^3.0 AND tags:(1234)", I do not get this document in my results.
Of course, when I do "documentname:(*name*)^3.0" I get a parse error saying: '*' or '?' not allowed as first character in WildcardQuery.
How can I either enable wildcard query in my custom CMS.Search webpart?
First of all you have to make sure that a field you checking is in the index with proper name. documentname might not be in the index it can be called _title, depends how you index is set up. Get lukeall and check your index (it should be in \CMS\App_Data\CMSModules\SmartSearch\YourIndexName). You can use luke to test your searches as well.
For examples there is no tags but there is documenttags field.
P.S. Wildcards are working and you are right you can't use them as a first character by default (lucene documentation says: You cannot use a * or ? symbol as the first character of a search), but there is a way to set it up in lucene.net, although i dont know if there are setting for that in Kentico. But i dont think you need wildcards, so your query should be (assuming you have documentname and documenttags in the index):
+(documentname:"My-Name" AND documenttags:"tag1")
I am learning MongoDB. Getting confused on usage of "$"
I have collection as below schema:
{
_id: 1,
"name": "test",
"city": "gr",
"sector": "IT",
"salary":1000
}
I find below output on executing below query:
Query Result
db.user.find({salary:2000}); Works
db.user.find({$salary:2000}); does not work(unknown top level operator: $salary)
db.user.aggregate({$group:{_id:null,avg:{$avg:"$salary"}}}); Works
db.user.aggregate({$group:{_id:null,avg:{$avg:$salary}}}); does not work($salary is not defined)
db.user.aggregate({$group:{_id:null,avg:{$avg:"salary"}}}); gives wrong output.
Can anyone please explain,what is the syntactical significance of "" and $ in mongoDB.
Hi lets look at these queries
1- db.user.find({salary:2000});
2- db.user.find({$salary:2000});
Take a look at this for find.
According to this find takes {field: value}, your first query works because salary is valid field.
Your second query doesn't work becuase there is no field $salary
3- db.user.aggregate({$group:{_id:null,avg:{$avg:"$salary"}}});
4- db.user.aggregate({$group:{_id:null,avg:{$avg:$salary}}});
5- db.user.aggregate({$group:{_id:null,avg:{$avg:"salary"}}});
For aggregation, lets take a look at this $avg.
Here it says that $avg takes {$avg: expression}. So you are actually keeping expression over there not a field.
Now take a look at this for expression.
Expression can be field paths and system variables, literals, expression objects, and expression operators.
Query numbers 3,4,5 aren't expression objects or expression operators. So lets eliminate these options.
Now lets take a look at $literal.
It states that literals can be of any type, however MongoDB parses literals that start with a dollar sign as a path to a field.
Finally take a look at Field Path and System variables.
It states "To specify a field path, use a string that prefixes with a dollar sign $ ... For example, "$user" to specify the field path for the user field or "$user.name" to specify the field path to "user.name" field."
That means you are specifying $salary as path to the field in $avg:"$salary" and query number 3 works.
Query number 4 doesn't work because $salary is an invalid expression.
This should explain the significance of ""
Query number 5 is not working because again it doesn't find any field to average on. Though it works because its a valid query it simply returns null.
You could have had
db.user.aggregate({$group:{_id:null,avg:{$avg:"some_non_existent_field"}}});
And the query will still run fine but you will get null for your results.
I hope this helps, this was a lot of fun to gather.
I want to query the Field which are empty and which are not empty using Sensenet Odata Rest API. Their documentation mentions a filter function called 'length'. I have tried to query the field with the length operation but it fails with the error.
This is the filter I have used
$filter=length(Name) eq 2
Sense/Net 6.5.4.9496
Exception
"code": "NotSpecified",
"exceptiontype": "SnNotSupportedException",
"message": {
"lang": "en-us",
"value": "Unknown method: length"
},
Wiki Link http://wiki.sensenet.com/OData_REST_API
The length operation was included in the list of supported methods incorrectly, we apologise for that. SenseNet compiles these filters to Lucene queries and it is not possible to compose such a query in Lucene that performs an operation on a field.
(the remaining methods, like substringof or startswith can be compiled to a wildcard expression easily, so that should work)
Unfortunately 'empty' expressions are also not supported by Lucene, because of their document/term structure. So the following expression does not work either:
Description eq ''
Edit: as a workaround, developers may create a custom field index handler.
For every field you want to check for emptiness (e.g. Description), you may create a technical hidden bool field (IsDescriptionEmpty) in the content type definition. The only thing you have to create and define is a custom field index handler class. In your case it would inherit from the built-in bool field index handler and you could return a boolean index value based on whether the target field (in this case Description) is empty or not.
After this you would be able to define search exressions like the following:
+Type:File +IsDescriptionEmpty:true
Please check the wiki article below and the source code for index handler examples.
How to create a field indexhandler
I have this data in one column in postgresql
{
"geometry":{
"status":"Point",
"coordinates":[
-122.421583,
37.795027
]
},
and i using his query
select * from students where data_json LIKE '%status%' ;
Above query return results but this one does not
select * from students where data_json LIKE '%status:%' ;
How can fix that
Of course the 2nd one doesn't find a match, there's no status: text in the value. I think you wanted:
select * from students where data_json LIKE '%"status":%'
... however, like most cases where you attempt text pattern matching on structured data this is in general a terrible idea that will bite you. Just a couple of problem examples:
{
"somekey": "the value is \"status\": true"
}
... where "status": appears as part of the text value and will match even though it shouldn't, and:
{
status : "blah"
}
where status has no quotes and a space between the quotes and colon. As far as JavaScript is concerned this is the same as "status": but it won't match.
If you're trying to find fields within json or extract fields from json, do it with a json parser. PL/V8 may be of interest, or the json libraries available for tools like pl/perl, pl/pythonu, etc. Future PostgreSQL versions will have functions to get a json key by path, test if a json value exists, etc, but 9.2 does not.
At this point you might be thinking "why don't I use regular expressions". Don't go there, you do not want to try to write a full JSON parser in regex. this blog entry is somewhat relevant.
It is possible to use "AND" while querying for Objects in Entity like
Post.find("byTitleLikeAndAuthor", "%hello%", connectedUser).fetch();
but is it possible to user "OR" while querying, like
Post.find("byNameOrEmail", name, email).fetch();
Thank you
Fixed!!
Use Post.find(" name = ? or email ?", name, email).fetch();
While using "where" in the query, it fails saying "unexpected token"
It is indeed possible to use "And" clauses when constructing objects, but I'm not aware of a possibility in simplified query to use "Or".
However, play can be used in many ways. Instead of writing :
Post.find("byNameOrEmail", name, email).fetch();
You can write :
Post.find("name = ? or email = ?", name, email).fetch();
using JPQL syntax.
It's not possible to use simplified query with or. To enable it you must change the implementation of findByToJPQL in the class play.db.jpa.JPQL. Wrote test and enhance the documentation and create a patch.
How ever you can use the JPQL.