MINGW + SQLITE3 - DLL / Linker Issues - c

Question

Trying to call SQLITE3 functions in MINGW C - program does not behave as expected. I suspect the issue is around the .a file but cannot see where or why there is no output.
Installed latest MinGW Distro from nuwen.net on Windows 10 in c:\mingw.
C:\c>gcc -v
Using built-in specs.
COLLECT_GCC=gcc
COLLECT_LTO_WRAPPER=c:/mingw/bin/../libexec/gcc/x86_64-w64-mingw32/8.1.0/lto-wrapper.exe
Target: x86_64-w64-mingw32
Configured with: ../src/configure --enable-languages=c,c++ --build=x86_64-w64-mingw32 --host=x86_64-w64-mingw32 --target=x86_64-w64-mingw32 --disable-multilib --prefix=/c/temp/gcc/dest --with-sysroot=/c/temp/gcc/dest --disable-libstdcxx-pch --disable-libstdcxx-verbose --disable-nls --disable-shared --disable-win32-registry --with-tune=haswell --enable-threads=posix --enable-libgomp
Thread model: posix
gcc version 8.1.0 (GCC)
Downloaded sqlite-amalgamation-3260000.zip, sqlite-dll-win64-x64-3260000.zip and sqlite-tools-win32-x86-3260000.zip from sqlite.org.
The headers sqlite3.h and sqlite3ext.h were copied from sqlite-amalgamation-3260000.zip to the include\sqlite3 directory.
The files sqlite3.def and sqlite3.dll were extracted from sqlite-dll-win64-x64-3260000.zip to a temporary directory.
In the temporary directory, I ran dlltool -U -d sqlite3.def -l libsqlite3.a (as described in http://www.mingw.org/wiki/createimportlibraries).
(note I tried with and without -U and -k flags)
No messages were output and the libsqlite3.a file is approx 200K (although I note .DLL is 10x size). I copied the resultant libsqlite3.a to the lib directory.
I write a quick test3.c program just to check I can call an sqlite function correctly:
#include <stdio.h>
#include "sqlite3\sqlite3.h"
sqlite3* db;
int main() {
printf("Start\n");
sqlite3_open("test.db", &db);
if(db == 0) {
printf("Could not open database.\n");
}
else {
printf("Database Open \n");
}
}
I compile with no errors using: gcc test3.c -lsqlite3
I run a.exe and see absolutely nothing - not even the "Start" string printed
I comment out just the "sqlite3_open" line and recompile with same command then run again and I see
C:\c>a
Start
Could not open database.
As behaviour is unexpected when calling an sqlite3 function, and as the .a file is a tenth of the size of the .DLL, I suspect the problem is there - but still cannot see why the "Start" is not output.