Allow to use repository query parameters to define a part of key in @Query [DATAMONGO-351]

[spring-projects-issues]

Stanislav Tyurikov opened DATAMONGO-351 and commented

One of my entity contains a java.util.Map field. After persistence it is transformed to a document like this:

{ lang: 
  {
     Java: 1000,
     Groovy: 2000,
     Xml: 3000,
  }
}

lang is the name of the map field. "Java", "Groovy" and "XML" are keys in the map, 1000, 2000, 3000 - the values.

I want to create a query method on a repository instance to select documents which contain desirable key and value:

@Query(" { lang.?0 : ?1 } " )
MyEntity findByLangAndValue(String someLang, long someValue);

The problem is then parameters are mapped to a query to execute, ?0 is replaced with someLang's value arounded with quotes. i.e. call findByLangAndValue("Java", 1000) transformed to query: \{ lang.\"Java\" : "1000" \} which fails to execute. Arounding a key part with quotes looks like a bug. At least it makes impossible to create query such as in my case

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No further details from DATAMONGO-351

[spring-projects-issues]

Oliver Drotbohm commented

This is not a bug in a strict sense as the parameter binding is intended to be used to bind parameter values not keys. However I don't think it's a bad idea to implement so I'll transform this into a feature request

[spring-projects-issues]

Stanislav Tyurikov commented

Oliver, thanks! I will wait for implementation

[spring-projects-issues]

William Bartlett commented

Without this it is impossible to write a query based on map keys or values.

Suppose the example class MyEntity were defined in Java as follows:

@Document
public class MyEntity {
    Map<String, Integer> lang;

    ...
}

The query created by Spring Data MongoDB for the following repository method is useless:

MyEntity findByLang(long value);

It uses query { "lang": ?0 }, which will never match a single document

[spring-projects-issues]

Christoph Strobl commented

The issue has been resolved in the past few years. Works as designed with current master (3.0).

@Query("{ 'address.?0' : ?1 }")
List<Person> findByAddressCity(String part, String value);