Question

我在tableview中使用SQLite数据库加载了一些数据，格式为1）某些值，2）某些值等等。 1和2是主键，这是我的删除代码，我已经在表格视图的删除功能上滑动了

-(void)tableView:(UITableView *)tableView commitEditingStyle:(UITableViewCellEditingStyle)editingStyle forRowAtIndexPath:(NSIndexPath *)indexPath
{
    [self openDB];
    NSString *idofTable = [NSString new];
    NSScanner *scanner = [[NSScanner alloc] initWithString:[self.tableLogView cellForRowAtIndexPath:indexPath].textLabel.text];
    [scanner scanUpToString:@")" intoString:&idofTable];

    NSLog(@"id=%@, text=%@", idofTable, [self.tableLogView cellForRowAtIndexPath:indexPath].textLabel.text);

    if(editingStyle==UITableViewCellEditingStyleDelete)
    {
        char *error;

        NSString *sql = [NSString stringWithFormat:@"DELETE FROM History WHERE 'id' = '%@'", idofTable];

        NSLog(@"%@",sql);

        if(sqlite3_exec(db, [sql UTF8String], NULL, NULL,&error)!=SQLITE_OK)
        {
            sqlite3_close(db);
            NSAssert(0,@"Could not create table");

        }
        else
        {
            NSLog(@"Data Deleted");
            sqlite3_exec(db, "COMMIT", NULL, NULL, &error);
        }
    }
    [tableLogView reloadData];
}

日志“已删除数据”已打印，但数据未在数据库或tableview中删除。任何帮助赞赏。我不知道错误发生在哪里，查询似乎是正确的。

Answer 1

试试这个

 if(editingStyle==UITableViewCellEditingStyleDelete)
        {
            NSString *dbFilePath =[DBclass getDBPath];

            sqlite3_stmt *deleteStmt = nil;
         if(sqlite3_open([dbFilePath UTF8String], &database)==SQLITE_OK)
        {

        NSString *deleteString=[NSString stringWithFormat:@"delete from table where ID =%d",idValue];
        const char *sql =[deleteString UTF8String];

        if(sqlite3_prepare_v2(database, sql, -1, &deleteStmt, NULL) != SQLITE_OK)
            NSAssert1(0, @"Error while creating delete view statement. '%s'", sqlite3_errmsg(database));

        if(SQLITE_DONE != sqlite3_step(deleteStmt))
            NSAssert1(0, @"Error while deleting data. '%s'", sqlite3_errmsg(database));
        else
            NSLog(@"Success in deleting the medicine.");

        sqlite3_close(database);
    }
        }
        [tableLogView reloadData];

Answer 2

您尚未最终确定或关闭数据库。

sqlite3_finalize(stmt);

sqlite3_close(DB);

Answer 3

这是删除行的正确方法：

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

   NSString *sql = [NSString stringWithFormat:@"DELETE FROM History WHERE 'id' = '%@'", idofTable];

   const char *del_stmt = [sql UTF8String];
   sqlite3_prepare_v2(contactDB, del_stmt, -1, & deleteStmt, NULL);
   if (sqlite3_step(deleteStmt) == SQLITE_DONE)
   {
       NSLog(@"Data Deleted");
       sqlite3_exec(db, "COMMIT", NULL, NULL, &error);
   }else {
       NSLog( @"Error: %s", sqlite3_errmsg(database) );
   }
   sqlite3_finalize(deleteStmt);
   sqlite3_close(contactDB);


}

使用SQLite不会从数据库中删除数据

3 个答案: