NSMutableArray会覆盖这些值(NSMutableArray overwrites the values)

 也许我是盲目的，但我无法弄清楚我做错了什么。 
 
 在2次运行之后（数据库中只有2个值），我得到2个不同的值，就像它应该的那样。 然后我把它写入NSMutableArray。 
 
 但是只有第二个值两次。 它不应该添加到数组的末尾吗？ 我做错了什么？ 
 
- (NSMutableArray *)getItemsFromDatabaseWithName:(NSString *)databaseName fromTable:(NSString *)tableName andConstraint:(NSString *)constraint
{
    NSString *absolutePath = [[NSBundle mainBundle].resourcePath stringByAppendingPathComponent:databaseName];
    NSLog(@"%@", absolutePath);

    //Datenbank öffnen --- "**" bedeuten "&" verwenden
    sqlite3_open([absolutePath UTF8String], &_database);

    //check if there is a constraint and if not take 2nd statement
    if (![constraint isEqualToString:@""])
    {
        _statement = [NSString stringWithFormat:@"select * from %@ where %@",tableName, constraint];
    }
    else
    {
        _statement = [NSString stringWithFormat:@"select * from %@",tableName];
    }

    const char *charStatement = [_statement cStringUsingEncoding:NSUTF8StringEncoding];
    sqlite3_stmt *results;
    //new array to return values
    _mutableItemArray = [NSMutableArray new];
    //new ItemModel
    ItemModel *tmpItem = [ItemModel new];

    if (sqlite3_prepare_v2(_database, charStatement, -1, &results, NULL)== SQLITE_OK)
    {
        while (sqlite3_step(results) == SQLITE_ROW)
        {

            _charItemName =  (char *)sqlite3_column_text(results, 1);
            [tmpItem setItemName:[NSString stringWithUTF8String:_charItemName]];

            _charItemDescription = (char *)sqlite3_column_text(results, 2);
            [tmpItem setItemDescription:[NSString stringWithUTF8String:_charItemDescription]];

            _charItemYear = (char *)sqlite3_column_text(results, 3);
            [tmpItem setItemYear:[_dateFormat dateFromString:[NSString stringWithUTF8String:_charItemYear]]];

            _charItemRecommendedBy = (char *)sqlite3_column_text(results, 4);
            [tmpItem setItemRecommendedBy:[NSString stringWithUTF8String:_charItemRecommendedBy]];

            _charItemImage = (char *)sqlite3_column_text(results, 5);
            [tmpItem setItemImage:[NSString stringWithUTF8String:_charItemImage]];


            [_mutableItemArray addObject:tmpItem];

#warning here I get the 2 items correct
            NSLog(@"ItemName: %@",[tmpItem getItemName]);
            NSLog(@"ItemName: %@",[tmpItem getItemDescription]);
        }
    }
    sqlite3_close(_database);

#warning here I get 2 times the same item ???
    NSLog(@"ItemName: %@",[_mutableItemArray objectAtIndex:0]);
    NSLog(@"ItemName: %@",[_mutableItemArray objectAtIndex:1]);

    return _mutableItemArray;
}

perhaps I'm blind but I cant figure out what I am doing wrong. 
 
after the 2 runs (there are only 2 values in the database) I get 2 different values like it should be. Then I write it into the NSMutableArray. 
 
But there is only the 2nd value twice. Shouldnt it add to the end of the array? What do I do wrong?
 
- (NSMutableArray *)getItemsFromDatabaseWithName:(NSString *)databaseName fromTable:(NSString *)tableName andConstraint:(NSString *)constraint
{
    NSString *absolutePath = [[NSBundle mainBundle].resourcePath stringByAppendingPathComponent:databaseName];
    NSLog(@"%@", absolutePath);

    //Datenbank öffnen --- "**" bedeuten "&" verwenden
    sqlite3_open([absolutePath UTF8String], &_database);

    //check if there is a constraint and if not take 2nd statement
    if (![constraint isEqualToString:@""])
    {
        _statement = [NSString stringWithFormat:@"select * from %@ where %@",tableName, constraint];
    }
    else
    {
        _statement = [NSString stringWithFormat:@"select * from %@",tableName];
    }

    const char *charStatement = [_statement cStringUsingEncoding:NSUTF8StringEncoding];
    sqlite3_stmt *results;
    //new array to return values
    _mutableItemArray = [NSMutableArray new];
    //new ItemModel
    ItemModel *tmpItem = [ItemModel new];

    if (sqlite3_prepare_v2(_database, charStatement, -1, &results, NULL)== SQLITE_OK)
    {
        while (sqlite3_step(results) == SQLITE_ROW)
        {

            _charItemName =  (char *)sqlite3_column_text(results, 1);
            [tmpItem setItemName:[NSString stringWithUTF8String:_charItemName]];

            _charItemDescription = (char *)sqlite3_column_text(results, 2);
            [tmpItem setItemDescription:[NSString stringWithUTF8String:_charItemDescription]];

            _charItemYear = (char *)sqlite3_column_text(results, 3);
            [tmpItem setItemYear:[_dateFormat dateFromString:[NSString stringWithUTF8String:_charItemYear]]];

            _charItemRecommendedBy = (char *)sqlite3_column_text(results, 4);
            [tmpItem setItemRecommendedBy:[NSString stringWithUTF8String:_charItemRecommendedBy]];

            _charItemImage = (char *)sqlite3_column_text(results, 5);
            [tmpItem setItemImage:[NSString stringWithUTF8String:_charItemImage]];


            [_mutableItemArray addObject:tmpItem];

#warning here I get the 2 items correct
            NSLog(@"ItemName: %@",[tmpItem getItemName]);
            NSLog(@"ItemName: %@",[tmpItem getItemDescription]);
        }
    }
    sqlite3_close(_database);

#warning here I get 2 times the same item ???
    NSLog(@"ItemName: %@",[_mutableItemArray objectAtIndex:0]);
    NSLog(@"ItemName: %@",[_mutableItemArray objectAtIndex:1]);

    return _mutableItemArray;
}

原文：https://stackoverflow.com/questions/22422318