create function biantolunscore
returns @score1 (int)
begin  
select 刊物级别 as 刊物级别 , --这缺个逗号 
case  
when 刊物级别='核心期刊' then 100
when 刊物级别='一般期刊' then 90
when 刊物级别='报纸杂志' then 80
when 刊物级别='会议论文' then 70
end as score
from 论文
end --这缺个end

------解决方案--------------------
SQL code
CREATE TABLE chen
(
   id int,
   title varchar(20),
   types varchar(20)
)

INSERT INTO chen(id,title,types)VALUES(1,'第一刊物','核心期刊')
INSERT INTO chen(id,title,types)VALUES(2,'第二刊物','报纸杂志')
INSERT INTO chen(id,title,types)VALUES(3,'第三刊物','一般期刊')
INSERT INTO chen(id,title,types)VALUES(4,'第四刊物','核心期刊')
INSERT INTO chen(id,title,types)VALUES(5,'第五刊物','报纸杂志')
INSERT INTO chen(id,title,types)VALUES(6,'第六刊物','报纸杂志')
INSERT INTO chen(id,title,types)VALUES(7,'第七刊物','一般期刊')
INSERT INTO chen(id,title,types)VALUES(8,'第八刊物','会议论文')
INSERT INTO chen(id,title,types)VALUES(9,'第九刊物','会议论文')
INSERT INTO chen(id,title,types)VALUES(10,'第十刊物','核心期刊')