刚开始做ios开发的时候本地存储选择数据库的时候常用sqlite的第三方库FMDB，后来在上家公司用过Nosql数据库，一直在寻求一个方面快捷的本地存储的方式，偶然的机会接触到了realm数据，原理性的东西我就不讲了，大家可以看以下两篇文章技术参考文档，理论知识参考文档，以下让我介绍下realm数据库使用过程中需要注意的两点

1、封装方法，避免realm自带类对代码的侵染，废话不多说，直接上代码。

.h中的方法
/**

门诊检查的realm数据库中的对象

*/

@interface KKExamRLMModel : KKRLMBaseObject
//牙图的类
@property(strong,nonatomic)NSNumber<RLMInt> *tooth_type;
//客户id
@property(copy,nonatomic)NSString *client_id;
//客户姓名
@property(copy,nonatomic)NSString *name;
//前台接待ID
@property(copy,nonatomic)NSString *receive_man_id;
//前台接待
@property(copy,nonatomic)NSString *receive_man;
//其它口腔问题
@property(copy,nonatomic)NSString *remark;
//牙位图列表
@property(strong,nonatomic)NSString *tooth_list;
//导医
@property(strong,nonatomic)NSString *director_name;
//检查日期
@property(copy,nonatomic)NSString *record_date;
//门诊检查的id
@property(strong,nonatomic)NSString *examId;
//
@property(strong,nonatomic)NSString *examine_id;
//图片数组的序列化后的字符串
@property(strong,nonatomic)NSString *pics;
//主任ID
@property(copy,nonatomic)NSString *consult_man_id;
//咨询师
@property(copy,nonatomic)NSString *consult_man;
/**已经分诊主任姓名*/
@property(copy,nonatomic)NSString *consult_name;
/**
 保存或者更新门诊检查到本地草稿箱
 @param model 门诊检查对象
 @param block 是否保存成功的回调
 */
+(void)saveExameToDraftBoxWithExamModel:(KKExamModel *)model completeBlock:(void(^)(BOOL success))block;


/**
 获取草稿箱里面的数据
 @return 返回门诊检查数组
 */
+(NSArray<KKExamModel *> *)getExamsFromDrftBox;

/**
 从草稿箱删除草稿
 @param examId 草稿箱里面examId
 @param block 删除成功与否的回调
 */
+(void)deleteExamFromDraftWithExamId:(NSString *)examId completeBlock:(void(^)(BOOL success))block;

.m文件中的实现方法

@implementation KKExamRLMModel

/设置主键/

+(NSString *)primaryKey {
    return @"examId";
}

/数据保存和更新的方法/

+(void)saveExameToDraftBoxWithExamModel:(KKExamModel *)model completeBlock:(void(^)(BOOL success))block{
    KKExamRLMModel *rlmModel=[KKExamRLMModel convertToRLMExamModel:model];
    [KKExamRLMModel addorUpdateWithObject:rlmModel  afterBlock:^{
    }];
    RLMResults *results=[KKExamRLMModel getObjetctsWithWhere:[NSString stringWithFormat:@"examId='%@'",model.examId] sortedDescriptors:nil];
    if (results.count==0) {
        block(NO);
    }
    else {
        block(YES);
    }
}

/获取数据的方法/

+(NSArray<KKExamModel *> *)getExamsFromDrftBox {
    RLMSortDescriptor *descriptor=[RLMSortDescriptor sortDescriptorWithKeyPath:@"record_date" ascending:NO];
    NSMutableArray<KKExamModel *> *array=[NSMutableArray arrayWithCapacity:10];
    RLMResults *rlmArray=[KKExamRLMModel getAllObjectsWithSortedDescriptors:@[descriptor]];
    for (KKExamRLMModel *rlmModel in rlmArray) {
        KKExamModel *examModel=[KKExamRLMModel convertToExamModel:rlmModel];
        [array addObject:examModel];
    }
    return [array copy];
}

/删除数据的方法/

+(void)deleteExamFromDraftWithExamId:(NSString *)examId completeBlock:(void(^)(BOOL success))block{
    [KKExamRLMModel deleteObjectsWithWhere:[NSString stringWithFormat:@"examId='%@'",examId]];
    RLMResults *results=[KKExamRLMModel getObjetctsWithWhere:[NSString stringWithFormat:@"examId='%@'",examId] sortedDescriptors:nil];
    if (results.count==0) {
        block(YES);
    }
    else {
        block(NO);
    }
}

普通的对象转成realm对象

+(KKExamRLMModel *)convertToRLMExamModel:(KKExamModel *)model {
    KKExamRLMModel *rlmModel=[KKExamRLMModel alloc].init;
    unsigned int propertyCount = 0;
    objc_property_t *propertys = class_copyPropertyList([model class], &propertyCount);
    for (int i = 0; i < propertyCount; i ++) {
        objc_property_t property = propertys[i];
        const char * propertyName = property_getName(property);
        NSString *propertyStr=[NSString stringWithUTF8String:propertyName];
        if ([propertyStr isEqualToString:@"tooth_list"]) {
            rlmModel.tooth_list=[KKToothMapModel getDictsFromObjects:model.tooth_list].mj_JSONString;
        }
        else if ([propertyStr isEqualToString:@"pics"]&&[model.pics isKindOfClass:[NSMutableArray class]]){
            if (model.pics.count>1) {
                NSMutableArray *mutArray=[NSMutableArray arrayWithCapacity:9];
                for (int i=0; i<model.pics.count; i++) {
                    UIImage *tempImage=model.pics[i];
                    NSData *data = UIImageJPEGRepresentation(tempImage,0.5);
                    NSString *imageDataString = [data base64EncodedStringWithOptions:NSDataBase64Encoding64CharacterLineLength];
                    [mutArray addObject:imageDataString];
                }
                [rlmModel setValue:[KKJSON arrayToJson:mutArray] forKey:propertyStr];
            }
            else {
                 [rlmModel setValue:nil forKey:propertyStr];
              }
            
       }
       else {
            [rlmModel setValue:[model valueForKey:propertyStr] forKey:propertyStr];
        }
    }
    free(propertys);
    return rlmModel;
}

将realm对象转换成普通的对象

/将relam对象转换成普通的对象，避免reaml对象对本对象的侵染/

+(KKExamModel *)convertToExamModel:(KKExamRLMModel *)rlmModel {
    KKExamModel *examModel=[KKExamModel alloc].init;
    unsigned int propertyCount = 0;
    objc_property_t *propertys = class_copyPropertyList([KKExamRLMModel class], &propertyCount);
    for (int i = 0; i < propertyCount; i ++) {
        objc_property_t property = propertys[i];
        const char * propertyName = property_getName(property);
        NSString *propertyStr=[NSString stringWithUTF8String:propertyName];
        if ([propertyStr isEqualToString:@"tooth_list"]) {
            examModel.tooth_list=[[KKToothMapModel getObjectArrayWithKeyValuesArray:rlmModel.tooth_list.mj_JSONObject] mutableCopy];
        }
        else if ([propertyStr isEqualToString:@"pics"]) {
            NSArray *temarray=[KKJSON arrayFromJsonString:rlmModel.pics];
            for (NSString *str in temarray) {
                NSData *decodedImgData = [[NSData alloc] initWithBase64EncodedString:str options:NSDataBase64DecodingIgnoreUnknownCharacters];
                UIImage *decodedImage = [UIImage imageWithData:decodedImgData];
                [examModel.pics addObject:decodedImage];
            }
        }
        else {
            [examModel setValue:[rlmModel valueForKeyPath:propertyStr] forKey:propertyStr];
        }
    }
    free(propertys);
    return examModel;
}

/加这个方法为了保持代码的健壮性/

-(void)setValue:(id)value forUndefinedKey:(NSString *)key {
    NSLog(@"unDefinekey:%@",key);
}

以上代码的重点是realm对象和普通对象之间的相互转换。
realm封装详见realm数据库封装password:dugd