FMDB将对象放进数据库[一]

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写在前面:我使用了runtime来更好的运作,详见第二篇

http://www.cnblogs.com/hanjian/p/4359568.html

首先建立一个HJShop类,实现NSCoding协议

#import <Foundation/Foundation.h>

@interface HJShop : NSObject<NSCoding>

@property (nonatomic, copy)NSString *name;

@property (nonatomic, assign)double price;

@end

#import "HJShop.h"

@implementation HJShop

- (void)encodeWithCoder:(NSCoder *)aCoder

{

[aCoder encodeObject:self.name forKey:@"name"];

[aCoder encodeDouble:self.price forKey:@"price"];

}

- (id)initWithCoder:(NSCoder *)aDecoder

{

if (self = [super init]) {

self.name = [aDecoder decodeObjectForKey:@"name"];

self.price = [aDecoder decodeDoubleForKey:@"price"];

}

return self;

}

- (NSString *)description

{

return [NSString stringWithFormat:@"%@ - %f", self.name, self.price];

}

@end

-----------------------------------------------

然后使用FMDB框架

//初始化

NSString *path = [[NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) lastObject] stringByAppendingPathComponent:@"shop.sqlite"];

self.db = [FMDatabase databaseWithPath:path];

[self.db open];

//创表

[self.db executeUpdate:@"CREATE TABLE IF NOT EXISTS t_shop (id integer PRIMARY KEY, shop blob NOT NULL UNIQUE);"];

[self addShops];

[self readShop];

- (void)addShops

{

HJShop *shop = [[HJShop alloc] init];

shop.name = @"jack";

shop.price = 11.0;

NSData *data = [NSKeyedArchiver archivedDataWithRootObject:shop];

[self.db executeUpdateWithFormat:@"INSERT OR IGNORE INTO t_shop(shop) VALUES (%@);", data];

}

- (void)readShop

{

FMResultSet *set = [self.db executeQuery:@"SELECT * FROM t_shop;"];

while (set.next) {

NSData *data = [set objectForColumnName:@"shop"];

HJShop *shop = [NSKeyedUnarchiver unarchiveObjectWithData:data];

NSLog(@"%@", shop);

}

}

只要把对象encoding成二进制文件,就可以放进SQLite中去了

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