我如何在Objective-C中将其写为正确的SQLite3语句

Question

我在IOS项目中将以下语句写入我的Database Controller类时遇到了问题。

substringFromIndex

我理解需要使用let text = "Suuuuper, {1} has sent {2} a very cool present" let myTextBefore1 = text.substringToIndex(text.rangeOfString("{1}")!.startIndex) // "Suuuuper, " let myTextAfter2 = text.substringFromIndex(text.rangeOfString("{2}")!.endIndex) // " a very cool present" ，SELECT * FROM GPSJob WHERE sourceMonitor = '%@' AND positionNumber = %d; 和mysqlite3_open()，但我无法将我从步骤中提供的值转换为NSString和NSNumber！

Answer 1

你需要这样的东西：

 NSString *querySQL = @"SELECT * FROM GPSJob WHERE sourceMonitor = ? AND positionNumber = ?";

然后对String

使用以下内容

 sqlite3_bind_text(sqlite3_stmt*,int,const char*,int,void(*)(void*));

并关注int

 sqlite3_bind_int(sqlite3_stmt*, int, int);