解决方法：
        需要将SELECT es.name primary_school ,COUNT(DISTINCT esi.stu_id) primary_num FROM……、SELECT  es.name AS high_school,COUNT(DISTINCT esi.stu_id) AS high_num FROM……、SELECT COUNT(DISTINCT esi.stu_id) total_num FROM……的结果放到一起，由于结果之间没什么关系，先给获取到的结果添加编号，SELECT @rownumb:=@rownumb+1 AS rownum, resources.*   FROM (SELECT @rownumb:=0) r，（……）resources，然后根据编号将三个结果集合并起来：
SELECT c.rownum,b.high_school,b.high_num,a.primary_school,a.primary_num, c.total_num
FROM 
(……) b
LEFT JOIN 
(……) a 
ON a.rownum = b.rownum
LEFT JOIN
(……) c 
ON c.rownum = b.rownum
这个结果如果刚好b里面的行数最多是没有问题的，但问题是不知道a、b哪个里面的行数最多，解决这个问题，如果可以用full join就可以直接解决了，但full join对于使用的版本不可用，采取的方法是用union all将几个left join后得到的结果合并在一起：
SELECT DISTINCT high_school,high_num,primary_school,primary_num, total_num 
FROM 
 (SELECT c.rownum,b.high_school,b.high_num,a.primary_school,a.primary_num, c.total_num
 FROM 
 (……) b
 LEFT JOIN 
 (……) a 
 ON a.rownum = b.rownum
 LEFT JOIN  www.2cto.com  
 (……) c 
 ON c.rownum = b.rownum
UNION ALL
 SELECT c.rownum,b.high_school,b.high_num,a.primary_school,a.primary_num, c.total_num
 FROM 
 (……) a
 LEFT JOIN 
 (……) b 
 ON a.rownum = b.rownum
 LEFT JOIN
 (……) c 
 ON c.rownum = a.rownum
 ) ee