iphone：在我的SQLite数据库的表中创建一个查询

Question

，有一个名为域ID，名字，中间，姓氏

现在我想要运行的查询如下

MyQuery = [NSString stringWithFormat:@"select id,(firstName || middlename || lastname) as Name from Students where firstname like '%@' or middlename like '%@' or lastname like '%@'",searchBarString,searchBarString,searchBarString]; 

上面的查询工作做好。但我想在第一个和中间名（也是中间姓）之间添加一个空格。所以我该如何执行这个任务？请建议

Answer 1

MyQuery = [NSString stringWithFormat:@"select id,(firstName || ' ' || middlename || ' ' || lastname) as Name from Students where firstname like '%@' or middlename like '%@' or lastname like '%@'",searchBarString,searchBarString,searchBarString]; 

试试这个！

Answer 2

你可以简单地在不同的变量返回三个列，然后加入他们显示他们的时候：

NSString *lastName = ...; 
NSString *middleName = ...; 
NSString *firstName = ...; 

NSString *joined = [NSString stringWithFormat:@"%@ %@ %@",lastName,middleName,firstName]; 

这样做的好处是，你可以通过任何UI中的三列未做排序新的SQLite查询，并允许用户编辑这些。