The oracledecode function implements row-to-column conversion.

Use the decode function or casewhen to implement row-to-column Oracle ---- create test table createtablestudent_score (namevarchar2 (20), subjectvarchar2 (20), scorenumber (); ----- insert test data into (name, subject, score) values (Zhang San, Chinese, 78); in

Use the decode function or case when to convert rows to Oracle ---- create a test table create table student_score (name varchar2 (20), subject varchar2 (20), score number )); ----- insert test data insert into student_score (name, subject, score) values ('zhang san', 'China', 78); in

Use the decode function or case when to implement row-to-column Conversion
Oracle

---- Create test table create table student_score (name varchar2 (20), subject varchar2 (20), score number (); ----- insert test data insert into student_score (name, subject, score) values ('zhang san', 'China', 78); insert into student_score (name, subject, score) values ('zhang san', 'mat', 88 ); insert into student_score (name, subject, score) values ('zhang san', 'English ', 98); insert into student_score (name, subject, score) values ('Li si ', 'China', 89); insert into student_score (name, subject, score) values ('lily', 'mat', 76); insert into student_score (name, subject, score) values ('Li si', 'English ', 90); insert into student_score (name, subject, score) values ('wang 5', 'China', 99 ); insert into student_score (name, subject, score) values ('wang wu', 'mate', 66); insert into student_score (name, subject, score) values ('wang wu ', 'English ', 91); ----- select name "name" in the decode line, sum (decode (subject, 'China', nvl (score, 0), 0 )) "language", sum (decode (subject, 'mat', nvl (score, 0), 0) "Mathematics", sum (decode (subject, 'English ', nvl (score, 0), 0) "English" from student_score group by name; ------ select name "name ", sum (case when subject = 'China' then nvl (score, 0) else 0 end) "", sum (case when subject = 'mate' then nvl (score, 0) else 0 end) "Mathematics", sum (case when subject = 'English 'then nvl (score, 0) else 0 end) "English" from student_score group by name;