'SELECT 
student.*, 
count(doklady.id_doklady) as doklady_count,
count(konf.id_konf) as konf_count 

FROM #__asm_student as student

LEFT JOIN #__asm_doklady as doklady ON (student.id=doklady.id_student)
LEFT JOIN #__asm_konf as konf ON (student.id=konf.id_studentkonf)

GROUP BY student.id';

CREATE TABLE `lg5kt_asm_student` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `fakultet` varchar(255) DEFAULT NULL,
  `kurs` varchar(255) DEFAULT NULL,
  `gruppa` varchar(255) DEFAULT NULL,
  `fio` varchar(255) DEFAULT NULL,
  PRIMARY KEY (`id`)
) ENGINE=MyISAM AUTO_INCREMENT=6 DEFAULT CHARSET=utf8;
INSERT INTO `lg5kt_asm_student` VALUES (1,'ФИТ','3','10-ОЗИ','Иванов Антон Петрович');
INSERT INTO `lg5kt_asm_student` VALUES (2,'ФИТ','4','11-ОЗИ','Петров Иван Антонович');
INSERT INTO `lg5kt_asm_student` VALUES (3,'МТФ','3','iuiyuiui','yuiyuiyui');
INSERT INTO `lg5kt_asm_student` VALUES (4,'МТФ','6','5050','055050');
INSERT INTO `lg5kt_asm_student` VALUES (5,'МТФ','1','1010','1010');

CREATE TABLE `lg5kt_asm_doklady` (
  `id_doklady` int(11) NOT NULL AUTO_INCREMENT,
  `id_student` varchar(255) DEFAULT NULL,
  `vid` varchar(255) DEFAULT NULL,
  `strana` varchar(255) DEFAULT NULL,
  `name` varchar(255) DEFAULT NULL,
  `vyhodnie` varchar(255) DEFAULT NULL,
  `sredstv` varchar(255) DEFAULT NULL,
  `kopiya` varchar(255) DEFAULT NULL,
  PRIMARY KEY (`id_doklady`)
) ENGINE=MyISAM AUTO_INCREMENT=4 DEFAULT CHARSET=utf8;
INSERT INTO `lg5kt_asm_doklady` VALUES (1,'1','asd','asd','asd','asd','asdasd','asd');
INSERT INTO `lg5kt_asm_doklady` VALUES (2,'1','123',NULL,NULL,NULL,NULL,NULL);
INSERT INTO `lg5kt_asm_doklady` VALUES (3,'4','456','456',NULL,NULL,NULL,NULL);

CREATE TABLE `lg5kt_asm_konf` (
  `id_konf` int(11) NOT NULL AUTO_INCREMENT,
  `id_studentkonf` varchar(255) DEFAULT NULL,
  `vid_konf` varchar(255) DEFAULT NULL,
  `date_konf` date DEFAULT NULL,
  `name_konf` varchar(255) DEFAULT NULL,
  `sredstv_konf` varchar(255) DEFAULT NULL,
  `kopiya_konf` varchar(255) DEFAULT NULL,
  PRIMARY KEY (`id_konf`)
) ENGINE=MyISAM AUTO_INCREMENT=6 DEFAULT CHARSET=utf8;
INSERT INTO `lg5kt_asm_konf` VALUES (1,'1',NULL,NULL,NULL,NULL,NULL);
INSERT INTO `lg5kt_asm_konf` VALUES (2,'2',NULL,NULL,NULL,NULL,NULL);
INSERT INTO `lg5kt_asm_konf` VALUES (3,'4',NULL,NULL,NULL,NULL,NULL);
INSERT INTO `lg5kt_asm_konf` VALUES (4,'4',NULL,NULL,NULL,NULL,NULL);
INSERT INTO `lg5kt_asm_konf` VALUES (5,'4',NULL,NULL,NULL,NULL,NULL);

SELECT student.*, 
count(doklady.id_doklady) as doklady_count,
GREATEST(count(doklady.id_doklady),count(konf.id_konf)) as konf_count 
FROM #__asm_student as student
LEFT JOIN #__asm_doklady as doklady ON (student.id=doklady.id_student)
LEFT JOIN #__asm_konf as konf ON (student.id=konf.id_studentkonf)
GROUP BY student.id

SELECT student.*, 
  (select count(distinct doklady.id_doklady) 
    from #__asm_doklady as doklady 
    where doklady.id_student=student.id
  ) as doklady_count,
  (select count(distinct konf.id_konf)
    from #__asm_konf as konf 
    where konf.id_studentkonf=student.id
  ) as konf_count 
FROM #__asm_student as student

SELECT student.*, 
  (select count(distinct doklady.id_doklady) 
    from #__asm_doklady as doklady 
    where doklady.id_student=student.id
  ) as doklady_count,
  (select count(distinct konf.id_konf)
    from #__asm_konf as konf 
    where konf.id_studentkonf=student.id
  ) as konf_count 
FROM #__asm_student as student