Clever Geek Handbook

SQL query to return unique dates based on different Datetime column for current date?

I have the following table (well, the example below):

CID | LogDate       | RemDate  
1   | 2015-05-06    | 2015-10-01  
2   | 2015-05-06    | 2015-10-01  
2   | 2015-05-06    | 2015-10-30  
1   | 2015-01-03    | 2015-10-01  
1   | 2015-01-03    | 2015-10-01  
2   | 2015-04-06    | 2015-10-01  
2   | 2014-04-06    | 2015-10-01  
3   | 2015-05-06    | 2015-12-01

I only need to return lines that have a unique [remdate] at the current date, and ignore others, even if they have a matching [CID] ....

I expect to return to two unique rezdata ( 2015-12-01

and 2015-10-30

)

I hope I am not missing something obvious here, any help or pointers would be greatly appreciated.

+3


source to share


2 answers


If you only want to return remixes that appear once in the table, you can use aggregation for that with count

:

select remdate
from yourtable
group by remdate
having count(remdate) = 1


If you want to return those remdates that appear once after logdate

, just add this field to the sentence group by

.

+4


source


If you only need to remove duplicates, use DISTINCT.



SELECT distinct remdate, * FROM table
0


source






More articles:


All Articles