提供列=值與選擇分鐘日期欄，比較2列

Question

我具有以下表

sec_id|pri_id |date_col| 
abc| 1 |28-02-2017|  
bcd| 1 |09-01-2017|  
ef| 1 | | 
ghi| 2 |04-04-2017|  
jkl| 2 |05-05-2016| 

如果sec_id屬於相同pri_id然後選擇與sec_id最早日期，並給它值1和其他零。

輸出這樣的事情 output table

|sec_id |pri_id |date_col |new_column | 
|abc |1 |28-02-2017| 0| 
|bcd |1 |09-01-2017| 1| 
|ef |1 |  | 0| 
|ghi |2 |04-04-2017| 0| 
|jkl |2 |05-05-2016| 1| 

select f_id, s_id, case when min(cast(date_id as timestamp)) then 1 else 0 end as new_column from test_sc group by f_id,s_id. 

再加上有其他條件也是如此，如果date_col的null，則採取col_e ......如果col_e = R則1新new_col，如果col_e爲null，則採取col_f ..如果col_f具有最低值，就像明智的6個條件一樣。但同時只是date_col。

Answer 1

select * 
     ,case 
      when pri_id = min(pri_id) over (partition by sec_id) 
      then 1 
      else 0 
     end as new_column 

from mytable 

---

+-----+--------+------------+------------+ 
| dt | sec_id | pri_id | new_column | 
+-----+--------+------------+------------+ 
| ef |  1 | (null)  |   0 | 
| bcd |  1 | 2017-01-09 |   1 | 
| abc |  1 | 2017-02-28 |   0 | 
| jkl |  2 | 2016-05-05 |   1 | 
| ghi |  2 | 2017-04-04 |   0 | 
+-----+--------+------------+------------+ 

Answer 2

至於第一個問題而言，你可以嘗試以下操作：

SELECT t1.sec_id, 
     t1.pri_id, 
     t1.date_col, 
     CASE WHEN t1.date_col = t2.date_col THEN 1 ELSE 0 END AS new_column 
FROM my_table t1 
JOIN my_table t2 
    ON t1.pri_id = t2.pri_id 
AND t2.date_col = (SELECT MIN(date_col) 
         FROM my_table t3 
         WHERE t2.pri_id = t3.pri_id)