I have a collection called one-two and I would like to list a few of the documents in the collection:
FOR v IN one-two
RETURN v
But I get the following error:
Query: AQL: collection or view not found: one (while parsing)
How do I specify the collection with a - in the name?
I've tried the usual options, ', " and camelCasing it oneTwo but they all fail.
The ArangoDB documentation Collection and View Names clearly states that a dash (-) is permitted.
For normal REST requests operating on such a collection no escaping is needed.
However, in AQL a dash (-) can also be interpreted as a minus operator. That's why in a query, a name with a dash has to be put into backticks: `one-two`
But since this is only relevant for AQL, this information can be found in the AQL Syntax documentation, not in the documentation about collection names that you referenced.
Related
I am working on the below query and trying to implement an ArangoDB wildcard search. The criteria is very simple, I'd like to match records similar to the name or a number field and limit the records to 25. The query works but is very slow, taking upwards of 30seconds. The goal is to optimize this query and get it as close to sub second as possible. I'd like the query to function similar to how a MySQL LIKE would work, matching using the % wildcard on both sides.
https://www.arangodb.com/docs/stable/release-notes-new-features37.html#wildcard-search
Note, one thing I noticed is that in the release note examples, rather than using FILTER, they are using SEARCH.
Additional info:
name is alphanumeric
number is going to by an 8 digit number
LET str = CONCAT("%", 'test', '%")
LET search = (
FOR doc IN name_search
FILTER ANALYZER(doc.name LIKE str, "text_en") OR
FILTER ANALYZER(doc.number LIKE str, "text_en")
LIMIT 25
RETURN doc
)
RETURN SEARCH
FILTER doesn't utilize indices. To speedup your wildcard queries you have to create an ArangoSearch view over a collection and use SEARCH keyword.
Feel free to check the following interactive tutorial (see "LIKE Support" section):
https://www.arangodb.com/learn/search/arangosearch-tutorial-3-7/
I've been trying to create a filter matching the end of the whole field text.
For example, taking a text field with the text: the brown fox jumped over the lazy dog
I would like it to match with a query that searches for fields with values ending with g. Something like:
{
"search":"*",
"queryType":"full",
"searchMode": "any",
...
"filter":"search.ismatchscoring('/g$/','MyField')"
}
The result is only records where MyField contains values with words composed by a the single g character anywhere on the string.
Using the filter directly also produces no results:
{
"search":"*",
"queryType":"full",
"searchMode": "any",
...
"filter":"MyField eq '*g'"
}
As far as I can see, the tokenization will always be the base for the search and filter, which means that on the above query, $ is completely ignored and matches will be by word, not by field.
Probably I could use the keyword_v2 analyzer on this field but then I would lose the tokenizarion that I use when searching normally.
One possible solution could be defining a second field in your index, with the same value as ‘MyField’, but with a different analyzer (e.g. keyword_v2). That way you may still search over the original field while filtering over the other.
Regardless, you might have simplified the filter for the sake of the example, but otherwise it seems redundant to use search.ismatchscoring() when not combining with another filter clause via ‘or’ – one can use the search parameter directly.
Moreover, regex might not be working because the default queryType for search.ismatchscoring() is simple, not full - please see docs here
I have a fields in index with [Analyzer(<name>)] applied. This analyzer is of type CustomAnalyzer with tokenizer = Keyword. I assume it treats both field value and search text as one term each. E.g.
ClientName = My Test Client (in index, is broken into 1 term). Search term = My Test Client (broken in 1 term). Result = match.
But surprisingly that's not the case until I apply phrasal search (enclose term in double quotes). Does anyone know why? And how to solve it? I'd rather treat search term as the whole, then do enclosing
Regards,
Sergei.
This is expected behavior. Query text is processed first by the query parser and only individual query terms go through lexical analysis. When you issue a phrase query, the whole expression between quotes is treated as a phrase term and as one goes through lexical analysis. You can find a complete explanation of this process here: How full text search works in Azure Search.
I am newest in Lucene.
I'm using Lucene.NET version 2.9.4.
What is the difference between these queries?
the first is:
title:hello AND tags:word
the second is:
+title:hello +tags:word
I testing a software, and I note that the first returns 3 records, and the second returns many records.
I observe that the first returns records where title and tags fields are fuel, but the second returns records where title and tags can be empty.
Is it the difference?
There is no difference between the two. clause1 AND clause2 is effectively shorthand for +clause1 +clause2
Similarly: clause1 clause2 = clause1 OR clause2
Note, there is really no equivalent for +clause1 clause2 using the boolean operators.
Are you sending the query over the Internet, if you are and not urlencoding the request correctly it could be misinterting the '+' as an encoded space and therefore lucene just runs the second query as if the +'s not there which would just OR the two parts and give the results you get.
title:hello tags:word
test:1 AND NOT bool:true
returns 5 documents
but
test:1 AND (NOT bool:true)
returns 0 documents
Why?
Please Explain me the value of parentheses in lucene query formation
When you place (NOT bool:true) in parentheses it becomes a subquery, which is executed independent of the query test:1. NOT clauses in Lucene ONLY remove elements from the result set, they don't find anything. In SQL, for instance, you implicitly start with every value available, and filter elements which don't match clauses out. In Lucene, you start with nothing, and find results based on the clauses. The query NOT bool:true tells it what not to match, but doesn't give Lucene anything to find and return. Any query of the form:
(any query finding results) AND (NOT something)
Will find zero results, because, on it's own, NOT something finds nothing, and (something) AND (nothing) returns nothing. You can perform a search like that, by getting all values first, before the lonely NOT clause, like:
test:1 AND (*:* AND NOT bool:true)
However, that will perform very poorly, and your first example:
test:1 AND NOT bool:true
Is definitely the correct one.