日期問題

Question

要求找出近一個月的數據，日期應該怎樣寫？

Answer 1

select * from tb where dt>=add_months(to_date(sysdate),-1)

Answer 2

     EMPNO NAME                     DEPTNO     MGR_ID     SALARY       COMM HIREDATE           BIRTH              S                                                                                     
---------- -------------------- ---------- ---------- ---------- ---------- ------------------ ------------------ -                                                                                     
         2 David                       100          1       7000                               20-11月-60         M                                                                                     
         3 Peter                       200          1       8000                               10-10月-61         M                                                                                     
         4 Harry                       300          1       9000                               20-8月 -66         M                                                                                     
         1 Jack                        999                 10000                               01-1月 -50         M                                                                                     
         5 Ann                         100          2       3500                               18-3月 -85         F                                                                                     
         6 Sue                         200          3       5500                               21-2月 -77         F                                                                                     
         7 Mary                        300          4       6000                               03-4月 -70         F                                                                                     
         8 Sam                         100          2       4100                               19-9月 -74         M                                                                                     
         9 Allen                       200          3       3100                               31-3月 -82         M                                                                                     
        10 Scott                       300          4       2700                               21-7月 -84         M                                                                                     
        11 James                       100          2       2900                               25-6月 -80         M                                                                                     
        12 Apple                       200          3       1800                               19-3月 -90         F   表結構是這個樣子的 應該怎樣比較男女的年齡呢？

Answer 3

找出年龄最小的男女员工信息
select n.*
 from
 (
 SELECT m.*,
        row_number() over(PARTITION BY deptno,s ORDER BY birth desc) rn
   FROM employe m) n
   where n.rn = 1

Answer 4

1 \ select * from tb where dt>=add_months(to_date(sysdate),-1)2\ select  min(绝对值函数（t1.出生年月-t2.出生年月）)from tb t1,tb t2 
where t1.性别字段= 男 and
  t2.性别字段= 女 and 

Answer 5

1、select * from tb where dt>=add_months(to_date(sysdate),-1) 2、 select  min(ABS(t1.出生年月-t2.出生年月))from tb t1,tb t2  
where t1.性别字段= 男 and 
  t2.性别字段= 女 and  

Answer 6

这个只是第一个表的男的年龄于第二个表的女的的年龄差，where （t1.性别字段= 男 and  
  t2.性别字段= 女）or （t2.性别字段= 男 and  
  t1.性别字段= 女）