oracle 行转列 decode

----创建测试表 
create table student_score( 
       name varchar2(20), 
        subject varchar2(20), 
       score number(4,1)   
 ); 
   
 -----插入测试数据 
 insert into student_score (name,subject,score)values('张三','语文',78); 
 insert into student_score (name,subject,score)values('张三','数学',88); 
 insert into student_score (name,subject,score)values('张三','英语',98); 
 insert into student_score (name,subject,score)values('李四','语文',89); 
 insert into student_score (name,subject,score)values('李四','数学',76); 
 insert into student_score (name,subject,score)values('李四','英语',90); 
 insert into student_score (name,subject,score)values('王五','语文',99); 
insert into student_score (name,subject,score)values('王五','数学',66); 
insert into student_score (name,subject,score)values('王五','英语',91); 
 -----decode行转列 
 select name "姓名", 
       sum(decode(subject, '语文', nvl(score, 0), 0)) "语文", 
       sum(decode(subject, '数学', nvl(score, 0), 0)) "数学", 
       sum(decode(subject, '英语', nvl(score, 0), 0)) "英语"
   from student_score 
  group by name; 
 ------ case when 行转列 
 select name "姓名", 
        sum(case when subject='语文'
        then nvl(score,0) 
        else 0 
       end) "语文", 
        sum(case when subject='数学'
       then nvl(score,0) 
        else 0 
        end) "数学", 
       sum(case when subject='英语'
        then nvl(score,0) 
        else 0 
      end) "英语"
      from student_score 
     group by name;