SQL - displaying row where the next numeric value is also available - sql

Question

I have the following query:
SELECT CAST(year_week AS NUMERIC) as year_week FROM web_details where location = ''JF'' AND property_id = ''FARM''
which produces the following results.
YEAR_WEEK
201035
201036
201037
201039
201041
201044
201045
201048
What I actually want is to produce a set of results which only displays values if the consecutive value is available - so producing the following results...
YEAR_WEEK
201035
201036
201044
To add another spanner into the works, the column year_week is not a numeric value so has needed to be converted.
Thanks

Answer 1

SELECT
CAST(year_week AS NUMERIC) as year_week
FROM
web_details wd
WHERE
EXISTS(
SELECT
year_week
FROM
web_details wd2
WHERE
wd2.year_week = CASE(RIGHT(wd.year_week, 2))
WHEN '48' THEN CAST((CAST(LEFT(wd.year_week,4) AS INT) + 1) AS VARCHAR(4)) + '01'
ELSE LEFT(wd.year_week,4) + CAST((CAST(RIGHT(wd.year_week,2) AS INT) + 1) AS VARCHAR(2))
END
)

Answer 2

Basically, my approach is that you calculate another column that contains the next year_week value, and the join it to itself.
WITH myCTE AS (
SELECT year_week, CONVERT(VARCHAR(4),DATEPART(year,CONVERT(datetime,LEFT(year_week,4)) + (RIGHT(year_week,2) + 1) * 7 )) + RIGHT( '000' + CONVERT(VARCHAR(2),DATEPART(MONTH,CONVERT(datetime,LEFT(year_week,4)) + (RIGHT(year_week,2) + 1) * 7)),2) next_year_week
FROM web_details
WHERE ..........
)
SELECT T1.year_week, T2.year_week
FROM myCTE T1
INNER JOIN myCTE T2 ON T1.next_year_week = T2.year_week