update MSSQL Server table using CSV file.

Configure importing from a constant file and use the batch file like this:

@echo off

for %%i in (*.csv) do call :RUN_ONE %%i
goto END

:RUN_ONE

ren %%i import.csv

rem Load import.csv into SQL Server.

del import.csv

:END

For example, you may create a stored procedure that uses OPENROWSET to select data from a file:

INSERT INTO ... ( ... )
SELECT
    ...
FROM OPENROWSET(BULK '...import.csv',
    FORMATFILE = '...import.fmt', FIRSTROW = 2)

and use sqlcmd to execute the procedure. For example:

sqlcmd -S . -E -h -1 -d Database -Q "EXEC dbo.uspImport"