SQL: Inserting row for missing month(s)

问题

I have a table as follow:

|----------|----------|
|  DT      |  FLAG    |
|----------|----------|
| 2015-MAY |  E       |
| 2015-JUN |  H       |
| 2015-OCT |  E       |
| 2016-FEB |  E       |
|----------|----------|

That I would like to transform as follow:

|----------|----------|
|  DT      |  FLAG    |
|----------|----------|
| 2015-MAY |  E       |
| 2015-JUN |  H       |
| 2015-JUL |  V       |
| 2015-AUG |  V       |
| 2015-SEP |  V       |
| 2015-OCT |  E       |
| 2015-NOV |  V       |
| 2015-DEC |  V       |
| 2016-JAN |  V       |
| 2016-FEB |  E       |
|----------|----------|

Missing months are inserted with the FLAG V

Is there an easy way to that that ?

Thanks!

回答1:

Thanks jspcal for the link that inspired this answer.

Got it work with

CREATE OR REPLACE PROCEDURE FILL_DATE_GAP AS 
BEGIN
    INSERT INTO DUMMY_DATES 
    SELECT to_date(add_months(date '2015-01-01', level - 1), 'yyyy-mm-dd') mth, 
           'V'
    FROM   DUAL 
    connect by level <= 14
    MINUS
    SELECT DT, 
           FLAG
    FROM   DUMMY_DATES;
END FILL_DATE_GAP;

Demo

来源：https://stackoverflow.com/questions/50439903/sql-inserting-row-for-missing-months