我有一个tableview应用程序，我试图删除存储在sqilte浏览器中的数据。当我删除模拟器中的数据时，关闭并重新运行模拟器后数据不会重新出现。但是，当我打开使用sqlite浏览器保存原始数据的数据库时，删除的数据仍会出现在sqlite浏览器中。有人可以告诉我我失踪的是什么吗？
#import "DataAccess.h"
#import "sqlite3.h"
#import "Product.h"
#import "Company.h"
@implementation DataAccess
NSString *dbPathString;
sqlite3 *companyDB;
sqlite3 *productDB;
-(void) setCompanyListFromDB
{
NSLog(@"setCompanyListFromDB");
dbPathString = @"/Users/user/Desktop/telecom.db";
self.companyList = [self readCompanyDataFromDB];
NSLog(@"read all company data");
}
-(void) deleteCompany:(Company *)company andDeleteProduct:(NSIndexPath*)indexPath{
//pass the company from the tableview, then pass the row from the tablewview
Product *product = [company.products objectAtIndex:indexPath.row];
[self deleteProductFromDB:product.name];
[company.products removeObjectAtIndex:indexPath.row];
}
-(NSMutableArray*)readCompanyDataFromDB //returning companyList bc we want to use this for displaying in tableview
{
NSLog(@"readDataFromDB");
NSMutableArray *companyList = [[NSMutableArray alloc]init];
sqlite3_stmt *statement ;
if (sqlite3_open([dbPathString UTF8String], &companyDB)==SQLITE_OK) { //when we do this process for products, we can skip opening companyDB bc it is already open - just do it once
NSLog(@"sqlite3_open");
// Reading Companies ....................................Start
NSLog(@"Reading Companies");
NSString *querySQL = [NSString stringWithFormat:@"SELECT * FROM company"];
NSLog(@"Company SQL: %@", querySQL);
const char *query_sql = [querySQL UTF8String]; //converting to type of string C understands
if (sqlite3_prepare(companyDB, query_sql, -1, &statement, NULL) == SQLITE_OK)
{
NSLog(@"sqlite3_prepare");
while (sqlite3_step(statement)== SQLITE_ROW) //while stepping through database, if it returns a row it should keep going, cuts out if it returns something other than SQLITE_ROW
{
// 1|Apple|AAPL|593.1|apple.jpeg
NSString *companyID = [[NSString alloc]initWithUTF8String:(const char *)sqlite3_column_text(statement, 0)];
NSString *name = [[NSString alloc]initWithUTF8String:(const char *)sqlite3_column_text(statement, 1)];
NSString *stockSymbol = [[NSString alloc]initWithUTF8String:(const char *)sqlite3_column_text(statement, 2)];
NSString *stockPrice = [[NSString alloc]initWithUTF8String:(const char *)sqlite3_column_text(statement, 3)];
NSString *logo = [[NSString alloc]initWithUTF8String:(const char *)sqlite3_column_text(statement, 4)];
//Company *company = [Company initWithName:name logo:logo symbol:stockSymbol price:stockPrice];
Company *company = [[Company alloc]init];
company.companyID = companyID;
company.name = name;
company.logo = logo;
company.stockSymbol = stockSymbol;
company.stockPrice = stockPrice;
[company print];
[companyList addObject:company];
}
}
// Reading Companies ....................................Done
// Reading Products for each Company ....................................Start
sqlite3_close(companyDB);
}
for(Company *company in companyList){
NSMutableArray *productList = [self readProductDataFromDBForCompanyID:company.companyID ];
company.products = productList;
}
return companyList;
}
-(NSMutableArray*) readProductDataFromDBForCompanyID:(NSString*)companyId {
NSLog(@"readProductDataFromDB");
NSMutableArray *productList = [[NSMutableArray alloc]init];
sqlite3_stmt *statement ;
if (sqlite3_open([dbPathString UTF8String], &companyDB)==SQLITE_OK) { //when we do this process for products, we can skip opening companyDB bc it is already open - just do it once
NSLog(@"sqlite3_open");
// Reading Products ....................................Start
NSLog(@"Reading Products");
NSString *querySQL = [NSString stringWithFormat:@"select * from product where productid = %@", companyId];
NSLog(@"Product SQL: %@", querySQL);
const char *query_sql = [querySQL UTF8String]; //converting to type of string C understands
if (sqlite3_prepare(companyDB, query_sql, -1, &statement, NULL) == SQLITE_OK)
{
NSLog(@"sqlite3_prepare");
while (sqlite3_step(statement)== SQLITE_ROW) //while stepping through database, if it returns a row it should keep going, cuts out if it returns something other than SQLITE_ROW
{
NSString *name = [[NSString alloc]initWithUTF8String:(const char *)sqlite3_column_text(statement, 0)];
NSString *website = [[NSString alloc]initWithUTF8String:(const char *)sqlite3_column_text(statement, 2)];
NSString *productID = [[NSString alloc]initWithUTF8String:(const char *)sqlite3_column_text(statement, 3)];
Product *product = [[Product alloc]init];
product.productID = productID;
product.name = name;
product.website = website;
[product print];
[productList addObject:product];
}
}
// Reading Products ....................................Done
sqlite3_close(companyDB);
}
// insert into product values('iPad','0','http://www.apple.com/ipad/',1);
return productList;
}
-(void) deleteProductFromDB:(NSString*)productname{
if (sqlite3_open([dbPathString UTF8String], &companyDB)==SQLITE_OK) { //when we do this process for products, we can skip opening companyDB bc it is already open - just do it once
NSLog(@"sqlite3_open");
NSString *querySQL = [NSString stringWithFormat:@"delete from product where productname = '%@'", productname];
NSLog(@"Product Delete SQL: %@", querySQL);
const char *deleteQuery = [querySQL UTF8String]; //converting to type of string C understands
if (sqlite3_exec(companyDB, deleteQuery, NULL, NULL, nil)==SQLITE_OK)
{
NSLog(@"Product Deleted");
}
sqlite3_close(companyDB);
}
}
@end
答案 0 :(得分：0)
正如评论中提到的那样 - 当您的应用程序在iOS中运行时，它将被沙箱化。此外，如果您将sqlite数据库作为资源文件包含在您的应用程序中 - 它将进入应用程序文件夹中的/ Resources文件夹。并且该文件夹中的所有内容都不可写。
因此，如果您需要一个想要读/写的数据库，则需要将其放在应用程序文件夹中的/ Documents文件夹下。