@interface HMShopTool : NSObject
+ (NSArray *)shops;
+ (void)addShop:(HMShop *)shop;
@end
@implementation HMShopTool

static FMDatabase *_db;

• (void)initialize
  {
  // 1.打开数据库
  NSString *path = [[NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) lastObject] stringByAppendingPathComponent:@”shops.sqlite”];
  _db = [FMDatabase databaseWithPath:path];
  [_db open];

  // 2.创表
  [_db executeUpdate:@”CREATE TABLE IF NOT EXISTS t_shop (id integer PRIMARY KEY, name text NOT NULL, price real);”];
  }

• (void)addShop:(HMShop *)shop
  {
  [_db executeUpdateWithFormat:@”INSERT INTO t_shop(name, price) VALUES (%@, %f);”, shop.name, shop.price];
  }

• (NSArray *)shops
  {// 得到结果集
  FMResultSet set = [_db executeQuery:@”SELECT FROM t_shop;”];

  // 不断往下取数据
  NSMutableArray *shops = [NSMutableArray array];
  while (set.next) {
  // 获得当前所指向的数据
  HMShop *shop = [[HMShop alloc] init];
  shop.name = [set stringForColumn:@”name”];
  shop.price = [set doubleForColumn:@”price”];
  [shops addObject:shop];
  }
  return shops;
  }