select t.rank, t.Name from t_menu_item t;
10 CLARK
10 KING
10 MILLER
20 ADAMS
20 FORD
20 JONES
20 SCOTT
20 SMITH
30 ALLEN
30 BLAKE
30 JAMES
30 MARTIN
30 TURNER
30 WARD
--------------------------------
我们通过 10g 所提供的 WMSYS.WM_CONCAT 函数即可以完成 行转列的效果
select t.rank, WMSYS.WM_CONCAT(t.Name) TIME From t_menu_item t GROUP BY t.rank;
DEPTNO ENAME
------ ----------
10 CLARK, KING, MILLER
20 ADAMS, FORD, JONES, SCOTT, SMITH
30 ALLEN, BLAKE, JAMES, MARTIN, TURNER, WARD
例子如下:
SQL> create table idtable (id number,name varchar2(30));
Table created
SQL> insert into idtable values(10,'ab');
1 row inserted
SQL> insert into idtable values(10,'bc');
1 row inserted
SQL> insert into idtable values(10,'cd');
1 row inserted
SQL> insert into idtable values(20,'hi');
1 row inserted
SQL> insert into idtable values(20,'ij');
1 row inserted
SQL> insert into idtable values(20,'mn');
1 row inserted
SQL> select * from idtable;
ID NAME
---------- ------------------------------
10 ab
10 bc
10 cd
20 hi
20 ij
20 mn
6 rows selected
SQL> select id,wmsys.wm_concat(name) name from idtable
2 group by id;
ID NAME
---------- --------------------------------------------------------------------------------
10 ab,bc,cd
20 hi,ij,mn
SQL> select id,wmsys.wm_concat(name) over (order by id) name from idtable;
ID NAME
---------- --------------------------------------------------------------------------------
10 ab,bc,cd
10 ab,bc,cd
10 ab,bc,cd
20 ab,bc,cd,hi,ij,mn
20 ab,bc,cd,hi,ij,mn
20 ab,bc,cd,hi,ij,mn
6 rows selected
SQL> select id,wmsys.wm_concat(name) over (order by id,name) name from idtable;
ID NAME
---------- --------------------------------------------------------------------------------
10 ab
10 ab,bc
10 ab,bc,cd
20 ab,bc,cd,hi
20 ab,bc,cd,hi,ij
20 ab,bc,cd,hi,ij,mn
6 rows selected
个人觉得这个用法比较有趣.
SQL> select id,wmsys.wm_concat(name) over (partition by id) name from idtable;
ID NAME
---------- --------------------------------------------------------------------------------
10 ab,bc,cd
10 ab,bc,cd
10 ab,bc,cd
20 hi,ij,mn
20 hi,ij,mn
20 hi,ij,mn
6 rows selected
SQL> select id,wmsys.wm_concat(name) over (partition by id,name) name from idtable;
ID NAME
---------- --------------------------------------------------------------------------------
10 ab
10 bc
10 cd
20 hi
20 ij
20 mn
6 rows selected