Search notes:

C:\ProgamData

The directory pointed at with the environment variable %ALLUSERSPROFILE% (typically C:\ProgramData) is used to store application data.
The exact location of this directory is stored in the registry under HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\ProfileList in the value ProgramData.
The default seems to be %SystemDrive%\ProgramData (at which also the variable %ProgramData% points).
Some possible subdirectories might include

TODO

The environment variables %ALLUSERSPROFILE% and %PROGRAMDATA% have the same value, at least on Windows 10.

See also

The .NET enumeration System.Environment+SpecialFolder.
C:\Users\All Users is a symlink to C:\ProgramData.

Index

Fatal error: Uncaught PDOException: SQLSTATE[HY000]: General error: 8 attempt to write a readonly database in /home/httpd/vhosts/renenyffenegger.ch/php/web-request-database.php:78 Stack trace: #0 /home/httpd/vhosts/renenyffenegger.ch/php/web-request-database.php(78): PDOStatement->execute(Array) #1 /home/httpd/vhosts/renenyffenegger.ch/php/web-request-database.php(30): insert_webrequest_('/notes/Windows/...', 1788377754, '216.73.217.21', 'Mozilla/5.0 App...', NULL) #2 /home/httpd/vhosts/renenyffenegger.ch/httpsdocs/notes/Windows/dirs/ProgramData/index(72): insert_webrequest() #3 {main} thrown in /home/httpd/vhosts/renenyffenegger.ch/php/web-request-database.php on line 78