analytic-functions

Let's assume I extract some set of data. i.e. SELECT A, date FROM table I want just the record with the max date (for each value of A). I could write SELECT A, col_date FROM TABLENAME t_ext WHERE col_date = (SELECT MAX (col_date) FROM TABLENAME t_in WHERE t_in.A = t_ext.A) But my query is really long... is there a more compact way using ANALYTIC FUNCTION to do the same? The analytic function approach would look something like SELECT a, some_date_column FROM (SELECT a, some_date_column, rank() over (partition by a order by some_date_column desc) rnk FROM tablename) WHERE rnk = 1 Note that

I found one question answered with the Row_Number() function in the where clause. When I tried one query, I was getting the following error: "Msg 4108, Level 15, State 1, Line 1 Windowed functions can only appear in the SELECT or ORDER BY clauses." Here is the query I tried. If somebody knows how to solve this, please let me know. SELECT employee_id FROM V_EMPLOYEE WHERE row_number() OVER ( ORDER BY employee_id ) > 0 ORDER BY Employee_ID To get around this issue, wrap your select statement in a CTE, and then you can query against the CTE and use the windowed function's results in the where

I have a SQL query written by someone else and I'm trying to figure out what it does. Can someone please explain what the Partition By and Row_Number keywords does here and give a simple example of it in action, as well as why one would want to use it? An example of partition by: (SELECT cdt.*, ROW_NUMBER () OVER (PARTITION BY cdt.country_code, cdt.account, cdt.currency ORDER BY cdt.country_code, cdt.account, cdt.currency) seq_no FROM CUSTOMER_DETAILS cdt); I've seen some examples online, they are in bit too depth. Thanks in advance! Michael Buen PARTITION BY segregate sets, this enables you

I want to find the cumulative or running amount of field and insert it from staging to table. My staging structure is something like this: ea_month id amount ea_year circle_id April 92570 1000 2014 1 April 92571 3000 2014 2 April 92572 2000 2014 3 March 92573 3000 2014 1 March 92574 2500 2014 2 March 92575 3750 2014 3 February 92576 2000 2014 1 February 92577 2500 2014 2 February 92578 1450 2014 3 I want my target table to look something like this: ea_month id amount ea_year circle_id cum_amt February 92576 1000 2014 1 1000 March 92573 3000 2014 1 4000 April 92570 2000 2014 1 6000 February