Null pointer when trying to use Sqlite3 session

[ReneMuala]

Describe the bug
Poco is raising a null pointer exception when trying to execute a query on a session.

To Reproduce
perform any operation on a sqlite3 session

Expected behavior
the respective query should be executed

Logs
stdout

PS C:\Users\dte\Documents\Playground\cpp\oikia-api> xmake ; xmake r
[ 50%]: compiling.release src\main.cpp
[ 75%]: linking.release oikia-api.exe
[100%]: build ok, spent 4.437s
main 22
Null pointer

Screenshots

#include <iostream>
#include <Poco/Data/Session.h>
#include <Poco/Data/SQLite/Connector.h>

using namespace Poco::Data::Keywords;
using Poco::Data::Session;
using Poco::Data::Statement;

struct Person
{
 std::string name;
 std::string address;
 int age;
};

int main(int argc, char** argv) try
{
 Poco::Data::SQLite::Connector::registerConnector();

 Session session("SQLite", "sample.sqlite3");

 std::cout << __FUNCTION__ << " " << __LINE__ << std::endl;
 session << "DROP TABLE IF EXISTS Person", now;

 std::cout << __FUNCTION__ << " " << __LINE__ << std::endl;
 session << "CREATE TABLE person (Name varchar(50), Address varchar(50), Age integer(3))", now;

 Person person = {
   "John Doe",
   "Beira",
   20,
 };

 Statement insert(session);

 insert << "INSERT INTO Person VALUES (?,?,?)",
   use(person.name),
   use(person.address),
   use(person.age);

 std::cout << __FUNCTION__ << " " << __LINE__ << std::endl;
 insert.execute();

 Statement select(session);

 select << "SELECT Name, Address, Age FROM person",
   into(person.name),
   into(person.address),
   into(person.age),
   range(0, 1);
 std::cout << __FUNCTION__ << " " << __LINE__ << std::endl;
 while (!select.done())
 {
   select.execute();
   std::cout << person.name << ", " << person.address << ", " << person.age << "\n";
 }
 return 0;
}
catch (std::exception& e)
{
 std::cout << e.what() << std::endl;
}

Please add relevant environment information:

• OS Windows 11
• POCO 1.13.3
• SQlite3

Additional context
Im using xmake to get the depencency

[matejk]

@ReneMuala Does it work with Poco 1.14?

[HardwayLinka]

same issue with 1.14.2

[matejk]

Analysis

The exception is thrown at SessionImpl.cpp:89 when _pDB (SQLite database handle) is null:

Poco::Data::StatementImpl::Ptr SessionImpl::createStatementImpl()
{
    poco_check_ptr (_pDB);  // Throws NullPointerException if _pDB is null
    return new SQLiteStatementImpl(*this, _pDB);
}

POCO's test suite passes on the same code path:

./cmake-build/bin/DataSQLite-testrunner testSimpleAccess
OK (1 tests)

This indicates the POCO source code is correct.

Likely Cause: xmake Package Configuration

Both reporters use xmake to build. The xmake POCO package has some configuration that may cause issues:

1. POCO_UNBUNDLED is defined - uses external SQLite instead of POCO's bundled version
2. sqlite config is disabled by default - must be explicitly enabled
3. Static/shared library linkage issues with POCO_STATIC define

Questions for reporters

@ReneMuala @HardwayLinka Could you please provide:

1. Your xmake.lua configuration - specifically how you add POCO as a dependency
2. Is SQLite explicitly enabled? It should look like:

   add_requires("poco", {configs = {sqlite = true}})

3. Output of xmake -v when building (verbose mode shows linker commands)
4. Can you try with vcpkg or conan to rule out xmake-specific issues?

   vcpkg install poco[sqlite3]
   

This appears to be a build configuration issue rather than a POCO bug. We need more information about your xmake setup to confirm.