Ios 对于'；没有可见的@界面；HODatabasesManager'；声明选择器'；db'；

错误是：“HODatabasesManager”没有可见的@interface声明选择器“db”

#import "BaseDB.h"

@implementation BaseDB

- (void)executeInBackgroundSuccess:(void (^)(id))success {
    dispatch_async(backgroundQueue(), ^{
        id result = [self executeQuery];
        dispatch_async(dispatch_get_main_queue(), ^{
            if (success) {
                success(result);                
            }
        });
    });
}

- (FMDatabase *)fmDatabase {
    return [[HODatabasesManager shareInstance] db];
}

- (id)executeQuery {
    return nil;
}

dispatch_queue_t backgroundQueue() {
    static dispatch_once_t queueCreationGuard;
    static dispatch_queue_t queue;
    dispatch_once(&queueCreationGuard, ^{
        queue = dispatch_queue_create("vn.conglv.dbqueue", 0);
    });
    return queue;
}
@end

---

如何修复此问题？

是否在

HODatabasesManager

的头文件中声明了

db

？是否在

HODatabasesManager

的头文件中声明了

db

？