目录1.前言2.数据库约束2.1约束类型2.2 NULL约束2.3 NUIQUE:唯一约束2.4 DEFAULT:默认值约束2.5 PRIMARY KEY:主键约束2.6 FOREIGN KEY:外键约束2.7 CHECK约束3.表的设计 3.1一对一3.2一
Check it: - (IBAction)toggleFavorite { DataManager *data = [DataManager sharedDataManager]; NSMutableSet *favorites = data.favorites;
We want to add a comments/reviews feature to our website\'s plugin gallery, so users can vote up/down a particular plugin and leave an optional short comment about what they liked or didn\'t like abou