objective-c - fmdb executeUpdate 失败

Question

我做错了什么？这是一个非常简单的语句，但无法弄清楚导致它失败的原因

    FMDatabase *db = [FMDatabase databaseWithPath:appDelegate.databasePath];
    [db open];
        isSuccess = [db executeUpdate:@"INSERT INTO notes (title, comment, fk) values (?, ?, ?);", title, comment, fkID];

exception.name=NSInvalidArgumentException, exception.reason=-[__NSCFString comment]: 无法识别的选择器发送到实例 0x68a93f

注.h

#import <Foundation/Foundation.h>

@interface Note : NSObject

@property (strong, nonatomic) NSString *title;
@property (strong, nonatomic) NSString *comment;
@property (nonatomic) int fkID;

Answer 1

看看FMDB usage .

[db executeUpdate:@"INSERT INTO notes VALUES (?,?,?)", title, comment, [NSNumber numberWithInt:fkID]];  

提供给 -executeUpdate: 方法(或接受 va_list 作为参数的任何变体)的所有参数都必须是对象。