SELECT
    SUM(CASE WHEN HowManyDays <= 30 THEN thisAmt ELSE 0 END) AS aging_0_30,
    SUM(CASE WHEN HowManyDays >= 31 AND HowManyDays <=...

(1) Use differentials rather than full backups for most backups.  For example, daily diffs and only, say, weekly full backups.

(2) If you're not already using backup compression, and particularly if...

The value needs to be a string:

STRING_SPLIT('1008,1009,1011,1014',',')

A NULL value should not cause an error, ASCII(NULL) should just return NULL.

How do you define "week number"?  Are the first 7 days of the month "week 1", or is it based on specific day of the week?  For example, all weeks...

Increase the size of  your tempdb files.

Inside that same db, run this command:

EXEC sys.sp_help tblstudent

or this:

SELECT * FROM sys.columns WHERE name = 'tblstudent'

Either of those should give you info about the table to compare to the...

"tblstudent" already exists -- with a different number of columns -- so the create table statement is failing, but the insert still tries to execute.

If, as you say, you are querying by a single, unique PK value, the lookup should be quick...

I'll take a look at it a bit later today.

You're welcome.  Yeah, OUTER APPLY is pretty useful, like here when you kinda want a join but only want 1 row, not all of them.

;WITH CTE_ADMITS AS (
    SELECT A.*, ISNULL(LEAD(A.DISCHARGE_DATE, 1) OVER(PARTITION BY ID_NUM ORDER BY DISCHARGE_DATE), '20790601') AS NEXT_DISCHARGE
    FROM ADMITS A
)
SELECT A.*,...

IF the MMDDYYYY formatted string date is guaranteed to always be 8 characters, the following works (most of the posted code doesn't consider the inclusion of the ".txt") according...

I wasn't 100% sure if 101 and 102 could appear more than once in the risk table, so I coded it to allow that, just in case.

If each can appear...

What result do you want?  You never explicitly stated the results you want to see.