SQLite library

[magna]

I`m trying to write a library to access the sqlite3.dll.

So far I managed to get the version number:

CONST SQLITE3_DLL = "sqlite3.dll"

DECLARE dll_sqlite3_libversion_number AS "sqlite3_libversion_number" OF SQLITE3_DLL
     DIM RESULT AS INTEGER
END DECLARE

FUNCTION sqlite3_libversion_number() AS INTEGER
     dll_sqlite3_libversion_number
     RESULT=dll_sqlite3_libversion_number.RESULT
END FUNCTION

` Shows the version of the SQLITE DBMS as message.
SUB ShowDbVersion()
     ShowMessage "SQLite Version: "+STR$(sqlite3_libversion_number())
END SUB

But trying to open an existing database fails and crashes the whole app:

`int sqlite3_open
DECLARE dll_sqlite3_open AS "sqlite3_open" OF SQLITE3_DLL
     `const char *filename,   /* Database filename (UTF-8) */
     DIM filename AS STRING
 `sqlite3 **ppDb          /* OUT: SQLite db handle */
     DIM ppDb AS LONG BYADDRESS
     ` Result
     DIM RESULT AS INTEGER
END DECLARE

FUNCTION sqlite3_open(filename AS STRING, ppDb AS LONG BYADDRESS) AS INTEGER
     dll_sqlite3_open.filename=filename
     dll_sqlite3_open.ppDb=ppDb
     dll_sqlite3_open
     RESULT=dll_sqlite3_open.RESULT
END FUNCTION

DIM ppDB AS LONG ` global db handler

` Should open a SQLITE database but crashes the app.
SUB DbOpen()
     ShowMessage "SQLite Open: "+STR$(sqlite3_open("c:midgard_import.db3", ppDB))
END SUB

I doubt that I set the parameter types for the dll call correctly.

So how should I declare them?

[magna]

Maybe I didn`t make my question clear enough ...

How should I write my DECLARE-statement if the underlying C-function expects an argument like "sqlite3 **ppDb"?

I wrote "DIM ppDb AS LONG BYADDRESS", but are quite sure that this is wrong. Calling the so defined function crashes my app.

[fred]

For LPCTSTR lpExistingFileName (CopyFile function) see how i used it here http://fnxbasic.com/yabb/YaBB.pl?num=1250272046
Perhaps you have to declare it like: DIM filename AS STRING byaddress
Long is the same type as Integer, signed 4 byte, 32 bit.
I`m not sure if your declaration of ppDb is wrong or good...
Perhaps i can look in one of the sqlite wrappers.

[magna]

Defining filename as BYADDRESS is smart! In C its a pointer and might be modified, IIRC, so passing it by reference might be better.

But I fear that ppDb is declared wrongly.

EDIT:
I declared filename byaddress as you suggested but calling this function still crashes my app.  :(