Im trying add pivot table extension "pivot_vtab" (https://antonz.org/sqlite-pivot-table/) to my sqlite, according to item "3. Pivot extension" in manual. I compiled DLL, in UniConnection did load an extension, see manual here: https://docs.devart.com/unidac/using-sqlite.htm. This was OK.

Then I created table database with tables 'sales' (common table with only data) and 'v_sales' - pivot table from 'pivot_vtab' extension - code is here:

create virtual table v_sales using pivot_vtab (
  (select distinct product from sales),
  (select distinct year, year from sales),
  (select sum(income) from sales where product = ?1 and year = ?2)
);

* Exception class $C0000005 with message 'c0000005 ACCESS_VIOLATION'. Process Project1.exe (7996)

* Exception class EAccessViolation with message 'Access violation at address 00007FF97B88F1E3 in module 'sqlite3.dll'. Read of address FFFFFFFFFFFFFFFF'. Process Project1.exe (7996)

When executing table 'v_sales' from sqlite3.exe (not in Delphi), works correctly.

  UniConnection.SpecificOptions.Values['EnableLoadExtension'] := 'True';
  UniConnection.ExecSQL('SELECT load_extension(''pivot_vtab.dll'');');

  UniQuery.sql.Text := 'select * from v_sales;';
  UniQuery.ExecSQL; // here occures an error!!!

No idea where can be the problem ... thank you in advance for answers.