Question

我有一个应用程序，允许您将项目添加到列表中（从表格视图），当用户单击相应项目旁边的添加按钮时，它会调用以下+（void）addItem方法。一切正常，但经过大量测试（60-70背对背插入导致它返回SQL错误代码“无法打开数据库文件”，应用程序必须重新启动。任何想法？谢谢！

+(void)addItem:(NSString *)dbPath{

NSUserDefaults *prefs = [NSUserDefaults standardUserDefaults];

NSString *oldTrip = [prefs objectForKey:@"selectedList"];

NSString *table = @"The Table";

NSString *name = [prefs objectForKey:@"SelectedAddItem"];    
NSString *countStr = @"1";
NSString *doneStr = @"No";
NSString *noteStr = @"None";
NSString *orderStr = @"15";


sqlite3 *database;


if (sqlite3_open([dbPath UTF8String], &database) == SQLITE_OK) {

    const char *sqlStr = [[NSString stringWithFormat:@"Insert into '%@' Values (null,?,?,?,?,?,?)",oldTrip]UTF8String];        

    sqlite3_stmt *compiledStatement;


    if (sqlite3_prepare_v2(database, sqlStr, -1, &compiledStatement, NULL) == SQLITE_OK){

        sqlite3_bind_text(compiledStatement, 0,[oldTrip UTF8String], -1, SQLITE_TRANSIENT);
        sqlite3_bind_text(compiledStatement, 1,[name UTF8String], -1, SQLITE_TRANSIENT);
        sqlite3_bind_text(compiledStatement, 2,[table UTF8String], -1, SQLITE_TRANSIENT);
        sqlite3_bind_text(compiledStatement, 3,[countStr UTF8String], -1, SQLITE_TRANSIENT);
        sqlite3_bind_text(compiledStatement, 4,[doneStr UTF8String], -1, SQLITE_TRANSIENT);
        sqlite3_bind_text(compiledStatement, 5,[noteStr UTF8String], -1, SQLITE_TRANSIENT);
        sqlite3_bind_text(compiledStatement, 6,[orderStr UTF8String], -1, SQLITE_TRANSIENT);

    }

    if(sqlite3_step(compiledStatement) != SQLITE_DONE ) {


        NSString* messageString = [NSString stringWithFormat: @"%s\n\nPlease contact the developer if this error persists", sqlite3_errmsg(database)]; 

        UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Error inserting" message:messageString delegate:self cancelButtonTitle:@"OK" otherButtonTitles:nil];


        [alert show];
        [alert release];

    } else {

        sqlite3_reset(compiledStatement);

        sqlite3_finalize(compiledStatement);
    }

}

sqlite3_close(database);

}

要获取数据库信息，我使用：

- (NSString *) getDBPath {

NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory , NSUserDomainMask, YES);
NSString *documentsDir = [paths objectAtIndex:0];
return [documentsDir stringByAppendingPathComponent:@"ListDatabase.sql"];
}

Answer 1

如果仅在高负载下发生，您可能希望尝试打开数据库文件，而不是为每个操作打开和关闭它。我对SQLite不太熟悉，但你也可以通过每次重置绑定来重用编译语句（如果你在reset之前你不需要调用finalize不打算重用声明）。

也许您可以在视图控制器的viewDidLoad和viewDidUnload方法中打开和关闭数据库？

无法打开数据库文件

1 个答案: