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刪除我在那裏我試圖刪除存儲在瀏覽器sqilte數據的tableview應用。當我刪除模擬器中的數據時，關閉並重新運行模擬器後，數據不會再出現。然而，當我打開其中原始數據是使用SQLite瀏覽器保存在數據庫中，已刪除的數據仍顯示在瀏覽器的源碼。有人可以提醒我錯過了什麼嗎？泰伯維應用從SQLite數據庫
#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
是否運行在iPhone模擬器這個代碼？如果是這樣，運行代碼沙箱（模擬如何將手機/ iPad上的），所以你必須有絕對路徑，/Users/user/Desktop/telecom.db，可能不是在模擬的應用程序實際上是在寫數據庫。所以你可能只是在看數據庫的兩個不同的副本。 – orpheist
我在iOS模擬器上運行它。這很有趣。謝謝！ – user3525783