sql_formatado.txt

SELECT 
	`aulas`.`id` AS t0_r0, 
	`aulas`.`turma_id` AS t0_r1, 
	`aulas`.`aluno_id` AS t0_r2,
	`aulas`.`status` AS t0_r3,
	`aulas`.`created_at` AS t0_r4,
	`aulas`.`updated_at` AS t0_r5, 
	`aulas`.`preparation` AS t0_r6,
	`aulas`.`grammar` AS t0_r7, 
	`aulas`.`conversation` AS t0_r8,
	`aulas`.`oral_ou_lab` AS t0_r9,
	`aulas`.`total` AS t0_r10, 

	`turmas`.`id` AS t1_r0,
	`turmas`.`professor_id` AS t1_r1, 
	`turmas`.`disciplina_id` AS t1_r2,
	`turmas`.`quando` AS t1_r3, 
	`turmas`.`data` AS t1_r4, 
	`turmas`.`time` AS t1_r5, 
	`turmas`.`hora` AS t1_r6, 
	`turmas`.`semana` AS t1_r7, 
	`turmas`.`horario_id` AS t1_r8, 
	`turmas`.`created_at` AS t1_r9, 
	`turmas`.`updated_at` AS t1_r10, 
	`turmas`.`escola_id` AS t1_r11

	FROM `aulas`
		LEFT OUTER JOIN `turmas`
			ON `turmas`.id = `aulas`.turma_id
	WHERE
	(
		(`aulas`.`total` IS NULL)
		AND
		(`aulas`.aluno_id = 7)
	)
	ORDER BY turmas.quando

ou melhor:
SELECT aulas.*, turmas.*
	FROM `aulas`
		LEFT OUTER JOIN `turmas`
			ON `turmas`.id = `aulas`.turma_id
	WHERE
	(
		(`aulas`.`total` IS NULL)
		AND
		(`aulas`.aluno_id = 7)
	)
	ORDER BY turmas.quando
	
ou apenas um resumo monstrando o que foi executado:

SELECT aulas, turmas
FROM aulas
JOIN turmas
WHERE 
	aulas.total IS NULL	
	AND	
	aulas.aluno_id = 7