Difference in Days Between Two Dates with Years, Months, and Days - sql

Question

I'm not a SQL expert, would you know if it's possible to have a query provide Days Between Two Dates to count days outstanding with today's date and output: Years, Months, Days and outstanding days providing 30 Days, 60 Days, 90 Days?
If I Declare "Years, Months, Days" from "Check_Date" and "Created_Date".
SQL provides a separate window, and, I only see Declared "FromDate" time
with "ToDate" displaying total Years, Months, Days. I am looking for a way
to have results provide a roll BY "Created_Date" records and include:
Years, Months, Days and outstanding days providing 30 Days, 60 Days, 90 Days? Can you suggest something with a similar result?
Scrip Code:
DECLARE #FromDate DATETIME = '2015-01-01 00:00:00',
#ToDate DATETIME = '2019-09-18 00:00:00',
#Years INT, #Months INT, #Days INT, #tmpFromDate DATETIME
SET #Years = DATEDIFF(YEAR, #FromDate, #ToDate)
- (CASE WHEN DATEADD(YEAR, DATEDIFF(YEAR, #FromDate, #ToDate),
#FromDate) > #ToDate THEN 1 ELSE 0 END)
SET #tmpFromDate = DATEADD(YEAR, #Years , #FromDate)
SET #Months = DATEDIFF(MONTH, #tmpFromDate, #ToDate)
- (CASE WHEN DATEADD(MONTH,DATEDIFF(MONTH, #tmpFromDate, #ToDate),
#tmpFromDate) > #ToDate THEN 1 ELSE 0 END)
SET #tmpFromDate = DATEADD(MONTH, #Months , #tmpFromDate)
SET #Days = DATEDIFF(DAY, #tmpFromDate, #ToDate)
- (CASE WHEN DATEADD(DAY, DATEDIFF(DAY, #tmpFromDate, #ToDate),
#tmpFromDate) > #ToDate THEN 1 ELSE 0 END)
SELECT #FromDate FromDate, #ToDate ToDate,
#Years Years, #Months Months, #Days Days
SELECT DISTINCT
ge.Name, --table columns
ge.Entity_Type,
ge.Entity_Number,
bc.Super_Entity_ID,
ch.Check_Date, --check created
ch.Created_Date, --if payment was received
ch.Check_Number,
ch.Amount,
vn.Vendor_Name
Check_Date,Created_Date,DATEDIFF("DAY",Check_Date,Created_Date) AS DAY
FROM dbo.gl_entities AS ge
INNER JOIN
dbo.super_entity AS se
ON ge.Super_Entity_ID = se.Super_Entity_ID
INNER JOIN
dbo.bank_codes AS bc
ON se.Super_Entity_ID = bc.Super_Entity_ID
INNER JOIN
dbo.checks AS ch
ON bc.Bank_Code_ID = ch.Bank_Code_ID
INNER JOIN
dbo.vendors AS vn
ON ch.Vendor_ID = vn.Vendor_ID
WHERE
ge.Active = 1 and vn.active = 1 and (ge.IS_Shadow = 1 OR se.IS_Tiered = 0)
AND CHECK_DATE > '20150101 00:00:00'
AND CHECK_DATE< '20190918 00:00:00'
ORDER BY ch.Check_Date, ch.Created_Date

Answer 1

To simply repeat them in their own columns in the query:
DECLARE #FromDate DATETIME = '2015-01-01 00:00:00',
#ToDate DATETIME = '2019-09-18 00:00:00',
#Years INT, #Months INT, #Days INT, #tmpFromDate DATETIME
SET #Years = DATEDIFF(YEAR, #FromDate, #ToDate)
- (CASE WHEN DATEADD(YEAR, DATEDIFF(YEAR, #FromDate, #ToDate),
#FromDate) > #ToDate THEN 1 ELSE 0 END)
SET #tmpFromDate = DATEADD(YEAR, #Years , #FromDate)
SET #Months = DATEDIFF(MONTH, #tmpFromDate, #ToDate)
- (CASE WHEN DATEADD(MONTH,DATEDIFF(MONTH, #tmpFromDate, #ToDate),
#tmpFromDate) > #ToDate THEN 1 ELSE 0 END)
SET #tmpFromDate = DATEADD(MONTH, #Months , #tmpFromDate)
SET #Days = DATEDIFF(DAY, #tmpFromDate, #ToDate)
- (CASE WHEN DATEADD(DAY, DATEDIFF(DAY, #tmpFromDate, #ToDate),
#tmpFromDate) > #ToDate THEN 1 ELSE 0 END)
SELECT DISTINCT
ge.Name, --table columns
ge.Entity_Type,
ge.Entity_Number,
bc.Super_Entity_ID,
ch.Check_Date, --check created
ch.Created_Date, --if payment was received
ch.Check_Number,
ch.Amount,
vn.Vendor_Name,
Check_Date,Created_Date,DATEDIFF("DAY",Check_Date,Created_Date) AS DAY,
#FromDate FromDate, #ToDate ToDate, #Years Years, #Months Months, #Days Days
FROM
. . .
If you run into problems with the DISTINCT clause, you can always use a subquery. If you want Years, Months, Days to be different based on one of the columns, you'll have to elaborate and then we can move everything you did in the SET statements into the SELECT statement.
Without your tables and data I cannot test very well.

Answer 2

pseudocode to try and demonstrate moving set statements to select statements
declare #begin date = '2018-01-01'
declare #end date = '2019-01-01'
declare #middletest int = datediff("dd", #begin, #end)/2
declare #middledate date = dateadd("dd", #middletest, #begin)
declare #middlemonth int = month(#middledate)
select #middlemonth half_month, #middledate middle_date
-- ,other_columns here
from table
where something
Start replacing.
#middlemonth is in the select statement so replace it with month(#middledate).
declare #begin date = '2018-01-01'
declare #end date = '2019-01-01'
declare #middletest int = datediff("dd", #begin, #end)/2
declare #middledate date = dateadd("dd", #middletest, #begin)
select month(#middledate) half_month, #middledate middle_date
-- ,other_columns here
from table
where something
#middledate is now in the select statement in 2 places so replace it with dateadd("dd", #middletest, #begin) each time.
declare #begin date = '2018-01-01'
declare #end date = '2019-01-01'
declare #middletest int = datediff("dd", #begin, #end)/2
select month(dateadd("dd", #middletest, #begin)) half_month,
dateadd("dd", #middletest, #begin) middle_date
-- ,other_columns here
from table
where something
Continue along.
declare #begin date = '2018-01-01'
declare #end date = '2019-01-01'
select month(dateadd("dd", datediff("dd", #begin, #end)/2, #begin)) half_month,
dateadd("dd", datediff("dd", #begin, #end)/2, #begin) middle_date
-- ,other_columns here
from table
where something
And you can, as desired, replace things with values from the table. If the table has a column start_date and you want that to be the begin and then use the current date as the end:
select month(dateadd("dd", datediff("dd", start_date, getdate())/2, start_date)) half_month,
dateadd("dd", datediff("dd", start_date, getdate())/2, start_date) middle_date
-- ,other_columns here
from table
where something