Duplicate rows when trying to grab last row of another table - sql

Question

I am trying to grab the last (latest) blog article's link for each month using a stored procedure but I cannot seem to find a way past my problem.
Currently, my code below repeats the (the latest blog article's) 'LINK' column like so:
SELECT AVG(DATEPART(mm, b.blog_date)) AS MonthNum --CANNOT USE MONTHNUM IN ORDER BY UNLESS WRAPPED WITH AVG() [average], weird but works
, CAST(DateName(month, DateAdd(month, Datepart(MONTH, b.blog_date), -1)) AS varchar(24)) AS MONTH
, CAST(DATEPART(YEAR, b.blog_date) AS varchar(4)) AS YEAR
, CAST(count(b.blog_content) AS varchar(24)) as ARTICLES
, (SELECT TOP (1) b.blog_url
FROM Management.Blog
WHERE (website_owner_id = 2)
GROUP BY blog_date
, blog_url
ORDER BY blog_date DESC
) AS LINK
, CAST(DateName(month, DateAdd(month, Datepart(MONTH, b.blog_date), -1)) AS varchar(24)) + CAST(DATEPART(YEAR, b.blog_date) AS varchar(4)) AS ID
, blog_date as DATE
FROM Management.Blog b
WHERE b.website_owner_id = 2
GROUP BY CAST(DateName(month, DateAdd(month, Datepart(MONTH, b.blog_date), -1)) AS varchar(24))
, CAST(DATEPART(YEAR, b.blog_date) AS varchar(4))
, b.blog_url
, blog_date
, CAST(DateName(month, DateAdd(month, Datepart(MONTH, b.blog_date), -1)) AS varchar(24)) + CAST(DATEPART(YEAR, b.blog_date) AS varchar(4))
ORDER BY DATE DESC
I understand the code is horrible to read (& probably to execute on the SQL server too) but I'm in a position where I am only new to SQL server (coming from MySQL where I've only really had to use a basic select query) and I am open to any suggestions to changing the query and/or table design.
Essentially there should be no duplicates of the ID column (which is only really added in to assist in removing the duplicates and can be omitted if need be).

Answer 1

Without sample data I'm unable to test whether this would work
After FROM Management.Blog b
Add this
INNER JOIN(
SELECT MonthNum = DATEPART(MONTH, BL.blog_date))
,blog_date
,RN = ROW_NUMBER()OVER(ORDER BY BL.blog_date DESC)
,BL.blog_url
FROM Management.Blog BL
) X ON B.blog_date = X.blog_date
AND X.RN = 1
Replace
(SELECT TOP (1) b.blog_url
FROM Management.Blog
WHERE (website_owner_id = 2)
GROUP BY blog_date
, blog_url
ORDER BY blog_date DESC
) AS LINK
with
X.blog_url AS [LINK]
change this in GROUP BY
, b.blog_url
with
, x.blog_url

Answer 2

I non-functioning query usually does not do a very good job of conveying what someone wants. Based on your explanation:
I am trying to grab the last (latest) blog article's link for each month
I would expect something like this:
SELECT b.*
FROM (SELECT b.*,
ROW_NUMBER() OVER (PARTITION BY YEAR(b.blog_date), MONTH(b.blog_date), b.blog_url, b.website_owner_id
ORDER BY blog_date DESC
) as seqnum
FROM Management.Blog b
) b
WHERE b.website_owner_id = 2 AND
seqnum = 1;