怎么把表中的一个字段的全部值当成另一个表的每一列
比如一个表A（id，B，C，D），有四组值（1，b1，c1，d1），（2，b2,c2,d2）,(3,b1,c1,d3),(4,b2,c2,d4),把C下的值当成另一个表E的的列，E(ID,B,c1,c2),之后检索出这种形式：
  (1,b1,d1,d3)
  (2,b2,d2,d4)  
E表建不建都无所谓只要能检出这种形式就行。
   


------解决方案--------------------
CREATE TABLE Aa(ID NUMBER,b VARCHAR2(20),c VARCHAR2(20),d VARCHAR2(20));
INSERT INTO Aa VALUES (1, 'b1', 'c1', 'd1');
INSERT INTO Aa VALUES (2, 'b1', 'c2', 'd2');
INSERT INTO Aa VALUES (3, 'b2', 'c1', 'd3');
INSERT INTO Aa VALUES (4, 'b2', 'c2', 'd4');
INSERT INTO Aa VALUES (5, 'b3', 'c1', 'd5');
INSERT INTO Aa VALUES (6, 'b3', 'c2', 'd6');


 SELECT e.f1,e.f2,e.f3 FROM (
SELECT row_number()over(PARTITION BY f.f1 ORDER BY f.f1,f.f2) rn,f.f1,f.f2,f.f3
FROM (
SELECT A1.b f1, A1.d f2, A2.d f3
FROM (SELECT c.b, a.d
FROM Aa a, (SELECT DISTINCT b FROM Aa ORDER BY b) c
WHERE c.b = a.b
ORDER BY c.b, a.d) A1,
(SELECT c.b, a.d
FROM Aa a, (SELECT DISTINCT b FROM Aa ORDER BY b) c
WHERE c.b = a.b 
ORDER BY c.b, a.d) A2
 WHERE A1.b = A2.b AND a1.d<>a2.d
 ORDER BY a1.b,a1.d )f )e
 WHERE e.rn=1