To the point that others have made, ORMs will frequently make the mistake of using some form of unicode datatype and, if the underlying datatype doesn't match, then no...

You need an index on the ProximityCardNumber column in that table, or SQL will have to scan the full table every time the query runs.

SELECT Column1, COUNT(*) * Column1 AS SumColumn1
FROM dbo.table_name
WHERE Column2 = '1'
GROUP BY Column1
ORDER BY Column1

Reserved word, just use a different name.  I...

This looks like a recursive update, so it's best to go row by row (or, if you are willing, use Moden's "special" update method using a specific clustered index structure).

But,...

Corrected the code a bit, and added any leftover amount to the first work day of the month.

;WITH base_data AS (
    SELECT
  ...

I only filled in holidays / weekends for Jan, but this code should give you what you requested once you substitute in your own nonworkdays table.

;WITH base_data...

For a direct, single table update, the alias shouldn't be needed.

If the FROM clause with the same table name appears, or especially if there any JOINs, it's absolutely critical to...

I am not sure exactly what you mean.

What specifically do you/we need to do with column RE80_DATAMOV?

FYI, you can do it without creating a table, like so:

SELECT
    SQL_VARIANT_PROPERTY ( MyColumn2, 'BaseType' ) AS MyColumn2_BaseType,
    SQL_VARIANT_PROPERTY ( today,...

SELECT SUM(TRY_CAST(LEFT(RE80_VALORE, CHARINDEX('.', RE80_VALORE + '.')) AS int))

FROM dbo.RE80_MOVSCHPUNTI

I think it's a bit more complex than that, at least if you want to keep existing code.  Personally I would not try rewrite all existing INSERT(s) / UPDATE(s) on...

I'd create completely new tables.

One table to hold all the varchar values and their new int value, as you're already done, I'm sure.  Load it with all the distinct values...

<Is it true that for those reasons he/ I could not do this?>

No, SQL Server would never allow one file to be used by two different dbs at the same...

Less than four functions, anyone?

SELECT string, numbers
FROM ( VALUES
    ('Total # of bytes : 128270200832 (119.46GB)'),
    ('Total # of bytes...