Return just the last day of each month with SQL

Question

I have a table that contains multiple records for each day of the month, over a number of years. Can someone help me out in writing a query that will only return the last d

Answer 1

In SQL Server, this is how I usually get to the last day of the month relative to an arbitrary point in time:

select dateadd(day,-day(dateadd(month,1,current_timestamp)) , dateadd(month,1,current_timestamp) )

In a nutshell:

1. From your reference point-in-time,
2. Add 1 month,
3. Then, from the resulting value, subtract its day-of-the-month in days.

Voila! You've the the last day of the month containing your reference point in time.

Getting the 1st day of the month is simpler:

select dateadd(day,-(day(current_timestamp)-1),current_timestamp)

1. From your reference point-in-time,
2. subtract (in days), 1 less than the current day-of-the-month component.

Stripping off/normalizing the extraneous time component is left as an exercise for the reader.

Answer 2

SELECT * FROM YourTableName WHERE anyfilter 
AND "DATE" IN (SELECT MAX(NameofDATE_Column) FROM YourTableName WHERE
anyfilter GROUP BY
TO_CHAR(NameofDATE_Column,'MONTH'),TO_CHAR(NameofDATE_Column,'YYYY'));

Note: this answer does apply for Oracle DB

Answer 3

A simple way to get the last day of month is to get the first day of the next month and subtract 1.

Answer 4

SQL Server (other DBMS will work the same or very similarly):

SELECT
  *
FROM
  YourTable
WHERE
  DateField IN (
    SELECT   MAX(DateField)
    FROM     YourTable
    GROUP BY MONTH(DateField), YEAR(DateField)
  )

An index on DateField is helpful here.

PS: If your DateField contains time values, the above will give you the very last record of every month, not the last day's worth of records. In this case use a method to reduce a datetime to its date value before doing the comparison, for example this one.

Answer 5

Use the EOMONTH() function if it's available to you (E.g. SQL Server). It returns the last date in a month given a date.

select distinct
Date 
from DateTable
Where Date = EOMONTH(Date)

Or, you can use some date math.

select distinct
Date
from DateTable
where Date = DATEADD(MONTH, DATEDIFF(MONTH, -1, Date)-1, -1)

Answer 6

I did the following and it worked out great. I also wanted the Maximum Date for the Current Month. Here is what I my output is. Notice the last date for July which is 24th. I pulled it on 7/24/2017, hence the result

Year    Month   KPI_Date
2017    4       2017-04-28
2017    5       2017-05-31
2017    6       2017-06-30
2017    7       2017-07-24


    SELECT  B.Year ,
    B.Month ,
    MAX(DateField) KPI_Date
FROM    Table A
    INNER JOIN ( SELECT  DISTINCT
                        YEAR(EOMONTH(DateField)) year ,
                        MONTH(EOMONTH(DateField)) month
                 FROM   Table
               ) B ON YEAR(A.DateField) = B.year
                      AND MONTH(A.DateField) = B.Month
GROUP BY B.Year ,
    B.Month