Can't use interface access for database access when using Kotlin's suspend [DATACMNS-1687]

[spring-projects-issues]

RhysXia opened DATACMNS-1687 and commented

interface UserDao : CoroutineCrudRepository<User, Long> {
    @Query("SELECT * FROM user WHERE username = :$0")
    suspend fun findOneByUsername(username: String): User?
}

When calling the above code, an error will be reported, and the result cannot be obtained correctly. The error is as follows

org.springframework.data.repository.query.ParameterOutOfBoundsException: Invalid parameter index! You seem to have declared too little query method parameters!org.springframework.data.repository.query.ParameterOutOfBoundsException: Invalid parameter index! You seem to have declared too little query method parameters! at org.springframework.data.repository.query.Parameters.getParameter(Parameters.java:238) ~[spring-data-commons-2.3.0.M4.jar:2.3.0.M4] Suppressed: reactor.core.publisher.FluxOnAssembly$OnAssemblyException: 

According to my understanding, the reason for the error is that after the suspend function is compiled, a coroutine parameter is injected into the method. When springboot processes the parameter, it will try to process this parameter, then causes an error

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Affects: 2.3 M4 (Neumann)

Reference URL: spring-projects/spring-boot#20552

Issue Links:

• DATACMNS-1689 RepositoryMetadata.getReturnedDomainClass(...) returns Object for suspended methods

[spring-projects-issues]

Mark Paluch commented

Can you provide a reproducer? Which Spring Data module are you using?

[spring-projects-issues]

RhysXia commented

you can find a reproducer [here|https://github.com/RhysXia/issue-spring-data-r2dbc].

I provide two api, api "/users" can request to all users. api  "/users/{username}" can request the user with the specified username. The above problem will occur when requesting this api.
 

[spring-projects-issues]

Mark Paluch commented

Thanks a lot. That issue is created by Spring Data R2DBC. I filed spring-projects/spring-data-r2dbc#321 to track that issue

[spring-projects-issues]

Mark Paluch commented

While investigating the fix, we found another issue, see DATACMNS-1689