Retrieve data from sqlite in iPhone

Question

我有5列（ type_id,Type,Quantity,NumberCalories,Category_id ），我需要根据更改“ Category_id ”检索“ type ”。请帮助我他是我的代码

const char *sql = "select type_id,Type,Quantity,NumberCalories from FoodType where Category_id=?";

Answer 1

Pass the categoryId to the database method and modify your query as below

NSString *sqlQuery =[NSString stringWithFormat:@"select type_id,Type,Quantity,NumberCalories from FoodType where Category_id = %d",categoryId];

const char *sql= [sqlQuery UTF8String];