class java.math.BigInteger cannot be cast to class java.lang.Boolean-CodePudding

I am trying to check whether the room name in that building exists or not.If exists, then don't save else save the data into the table.So I have written this query.

 @Query(value = "select exists(select name,building from meetingroom "  
            "where building=?1 and name=?2)",nativeQuery = true)
Boolean existsByRoom(String building,String name);

Now it is showing BigInteger cannot be cast to class java.lang.Boolean Is there any way to solve this without effecting or changing the query.

CodePudding user response：

Simplest solution is here is to use JPA derived query. Assuming your entity is MeetingRoom

Boolean existsMeetingRoomByBuildingAndName(String building, String name);

CodePudding user response：

One solution is to use java.util.Optional like below. And you need to use BigInteger instead of Boolean because query will return BigInteger value when record exist.

    @Query(value = "select exists(select name,building from meetingroom "  
                    "where building=?1 and name=?2)",nativeQuery = true)
    Optional<BigInteger> existsByRoom(String building,String name);

And in service layer, you can check if the value is present.

    Optional<BigInteger> result = 
meetingRoomRepository.existsByRoom(meetingRoomRequest.getBuilding(),meetingRoomRequest.getName());
    if(result.isPresent()){
        return true;
    }
    return false;