SQL - 一个表 - 多列的计数

Question

我有多所学校，有多个年级和各种状态。 如果状态为-1或0，我需要得到每所学校每个年级的计数 这些都来自同一张桌子。 ＆＃39;学生＆＃39; 如果成绩等于0且学校等于1234，我需要计数 如果等级等于1且学校等于1234，则在该计数旁边 如果等级等于2且学校等于1234，则在该计数旁边 下一行是针对不同的学校，等等。每行不同的学校，每一行的等级从0到12。

我试过

select Sched_NextYearGrade,
    sum(case when Sched_NextYearGrade = ‘1’ then 1 else 0 end) as 'firstcount'
    sum(case when Sched_NextYearGrade = '2' then 1 else 0 end) as 'secondCount'
from Students 
Where (ENROLL_STATUS BETWEEN -1 AND 0)
group by Sched_NextYearGrade

我得到了

ORA-00911: invalid character
00911. 00000 -  "invalid character"
*Cause:    identifiers may not start with any ASCII character other than
           letters and numbers.  $#_ are also allowed after the first
           character.  Identifiers enclosed by doublequotes may contain
           any character other than a doublequote.  Alternative quotes
           (q'#...#') cannot use spaces, tabs, or carriage returns as
           delimiters.  For all other contexts, consult the SQL Language

有人可以帮忙吗？提前致谢

Answer 1

‘1’的引号错误。它们应该是简单的引号：'1'。