In Couchbase Java Query DSL, how do I filter for field-values that are not ASCII?

问题

Using Couchbase Java DSL, a query using "fish/piraña" gives a parse-error, but with "fish/piranha", there is no parse-error.

I had thought that the x() method would correctly wrap the non-ASCII Unicode string.

Using N1ql directly, this does work with any field name (except blank) or field value:

parameterized("SELECT * from" + bucket.name() + "WHERE" + fieldName + "= $v", placeholders))

How can this be done using the Java Query DSL?

    String species "fish/pira\u00f1a" ;
    Expression expForType = x("species").eq(x(species));
    OffsetPath statement = select("*").from(i(bucket.name())).where(expForType);
    N1qlQuery q = N1qlQuery.simple(statement);
    N1qlQueryResult result = bucket.query(q);

回答1:

So, it works via N1QL:

   N1qlParams params = N1qlParams.build().consistency(ScanConsistency.REQUEST_PLUS).adhoc(true);
   ParameterizedN1qlQuery query = N1qlQuery.parameterized("Select * from `quicktask` where species = 'fish/pira\u00f1a' ", JsonObject.create(), params);
   System.out.println(quickProcessHistoryRepository.getCouchbaseOperations().getCouchbaseBucket().query(query));

I'm still trying to understand the behavior via SDK, I will update this answer as soon as I find the issue.

回答2:

Documentation says it supports unicode.

https://docs.couchbase.com/server/6.0/n1ql/n1ql-language-reference/literals.html

Strings can be either Unicode characters or escaped characters.

回答3:

Json strings can have unicode characters.

insert into default values ("f1",{"name":"fish/pira\u00f1a"});
select * from default where name = "fish/pira\u00f1a";
 "results": [
    {
        "default": {
            "name": "fish/piraña"
        }
    }
    ]

Collation (ORDER BY, indexing, ....) and data types comparison are based on byte comparison not based on unicode character. If unicode character is single/fixed byte it will work but if the data is variable multi-bytes may not work because comparison is based on byte comparison.

来源：https://stackoverflow.com/questions/55323027/in-couchbase-java-query-dsl-how-do-i-filter-for-field-values-that-are-not-ascii

标签

unicode

couchbase

n1ql