oracle sql如何區分和刪除字段中的所有空值

Question

您好如何區分和刪除字段中的所有空值。 這是我原來的桌子。 我正在使用sqldeveloper和oracle。

EMPNO      LASTNAME             FIRSTNAME            05-MAY-15                   06-MAY-15                   07-MAY-15                   08-MAY-15                   09-MAY-15                 
---------- -------------------- -------------------- --------------------------- --------------------------- --------------------------- --------------------------- ---------------------------
00000113   REYESUE              MARIE                +000000000 08:04:00.000000                                                                                                                  
00000113   REYESUE              MARIE                                            +000000000 08:12:00.000000                                                                                      
00000113   REYESUE              MARIE                                                                        +000000000 08:04:00.000000                                                          
00000113   REYESUE              MARIE                                                                                                    +000000000 08:06:00.000000                              
00000113   REYESUE              MARIE                                                                                                                                +000000000 08:25:00.000000  
00000114   SANTOSY              MICHAELA             +000000000 08:03:00.000000                                                                                                                  
00000114   SANTOSY              MICHAELA                                         +000000000 08:04:00.000000                                                                                      
00000114   SANTOSY              MICHAELA                                                                     +000000000 08:08:00.000000                                                          
00000114   SANTOSY              MICHAELA                                                                                                 +000000000 08:05:00.000000                              
00000114   SANTOSY              MICHAELA                                                                                                                             +000000000 08:09:00.000000  

這就是我想要的輸出

EMPNO      LASTNAME             FIRSTNAME            05-MAY-15                   06-MAY-15                   07-MAY-15                   08-MAY-15                   09-MAY-15                 
---------- -------------------- -------------------- --------------------------- --------------------------- --------------------------- --------------------------- ---------------------------
00000113   REYESUE              MARIE                +000000000 08:04:00.000000  +000000000 08:12:00.000000  +000000000 08:04:00.000000  +000000000 08:06:00.000000 +000000000 08:25:00.000000
00000114   SANTOSY              MICHAELA             +000000000 08:03:00.000000  +000000000 08:04:00.000000  +000000000 08:08:00.000000  +000000000 08:05:00.000000 +000000000 08:09:00.000000

Answer 1

您可以使用聚合函數min ，例如：

select "EMPNO"
     , "LASTNAME"
     , "FIRSTNAME"
     , min("05-MAY-15") as "05-MAY-15"
     , min("06-MAY-15") as "06-MAY-15"
     , min("07-MAY-15") as "07-MAY-15"
     , min("08-MAY-15") as "08-MAY-15"
     , min("09-MAY-15") as "09-MAY-15"
from tbl
group by "EMPNO"
       , "LASTNAME"
       , "FIRSTNAME"