查询场景

Question

我必须执行一个查询，其中场景如下所示;

Col_1 Col_2 Col_3 Col_4 Col_5 
A  AB AC  AD  AE 
B  BC BD  BE  ? 
C  CD CE  ?  ? 
D  DE  ?  ?  ? 
E  ?  ?  ?  ? 

以下任何帮助是高度赞赏。

感谢， 阿米特

Answer 1

您为每列需要不同rows：

select 
    col_1 
    ,col_1 || min(col_1) over (order by ... rows between 1 following and 1 following) 
    ,col_1 || min(col_1) over (order by ... rows between 2 following and 2 following) 
    ,col_1 || min(col_1) over (order by ... rows between 3 following and 3 following) 
    ,col_1 || min(col_1) over (order by ... rows between 4 following and 4 following) 

Answer 2

{

SELECT CHR(64+LEVEL) AS A, 
DECODE(SIGN(4 - LEVEL) , -1, '?',CHR(64+LEVEL)||CHR(65 +LEVEL)) B, 
DECODE(SIGN(3 - LEVEL) , -1, '?',CHR(64+LEVEL)||CHR(66 +LEVEL)) C, 
DECODE(SIGN(2 - LEVEL) , -1, '?',CHR(64+LEVEL)||CHR(67 +LEVEL)) D, 
DECODE(sign(1 - level) , -1, '?',chr(64+level)||chr(68 +level)) E 
from dual connect by level <6; 

} 这上面使用Oracle 10g，其他数据库应该有一些其他的策略。