C++ API does not work

[vdemichev]

What happens?

Any query results in parser error.

To Reproduce

#include "duckdb.hpp"

using namespace duckdb;

int main() {
	DuckDB db;
	Connection con(db);

	con.Query("CREATE TABLE people(id INTEGER, name VARCHAR)")->Print();
	return 0;
}

Output: parser error, with random details:
One run:

Parser Error: syntax error at or near "8"
LINE 1: 8?x?♦
Another run:
Parser Error: syntax error at or near "X?O2B"
LINE 1: X?O2B

I was trying to run sample code from https://duckdb.org/docs/data/appender.

Environment (please complete the following information):

• OS: Windows 10
• DuckDB Version: 0.4.0, downloaded today from https://github.com/duckdb/duckdb/releases/download/v0.4.0/libduckdb-windows-amd64.zip
• DuckDB Client: build using MSVC 2022, Debug x64 default settings

Identity Disclosure:

• Full Name: Vadim Demichev
• Affiliation: Charite University Medicine Berlin

[Mytherin]

As what encoding are you saving the file? DuckDB expects UTF8 encoded strings.

[vdemichev]

I am not sure where I need to change the encoding. I tried both /utf-8 compiler flag in MSVC and replacing the query with
con.Query(u8"CREATE TABLE people(id INTEGER, name VARCHAR)")->Print();
The problem is still there...

[vdemichev]

This C interface example https://github.com/duckdb/duckdb/blob/master/examples/embedded-c/main.c works fine though...

[virtualsafety]

This C interface example https://github.com/duckdb/duckdb/blob/master/examples/embedded-c/main.c works fine though...

i am facing the same problem. C example can work fine ,but c++ can not.

[virtualsafety]

g++.exe -fdiagnostics-color=always -g -I"D:\Go\c-demo\c++" -L"D:\Go\c-demo\c++" -llibduckdb duckdb_cppintegration.cpp -o duckdb_cppintegration -std=c++11
In file included from duckdb_cppintegration.cpp:8:
duckdb.hpp:789:20: error: function 'duckdb::hugeint_t::hugeint_t()' definition is marked dllimport
789 | DUCKDB_API hugeint_t() = default;
| ^~~~~~~~~
duckdb.hpp:791:20: error: function 'duckdb::hugeint_t::hugeint_t(const duckdb::hugeint_t&)' definition is marked dllimport
791 | DUCKDB_API hugeint_t(const hugeint_t &rhs) = default;

[Tishj]

https://discourse.cmake.org/t/how-to-avoid-error-definition-is-marked-dllimport/2726/12
https://cplusplus.com/forum/general/169715/#msg848400
https://developercommunity.visualstudio.com/t/compilation-fails-for-non-movable-type-passed-to-c/309335#T-N396458

these posts seem related to this issue

[hannes]

Are you sure this is using MVSC? To me it looks like you are using G++/MinGW or something like that.

[virtualsafety]

Are you sure this is using MVSC? To me it looks like you are using G++/MinGW or something like that.

yes,i am using MinGW.

[virtualsafety]

Is it possible to support MinGW?

[Mytherin]

We don't actively support MinGW right now, aside from as part of the R client.

[github-actions]

This issue is stale because it has been open 90 days with no activity. Remove stale label or comment or this will be closed in 30 days.

[arnabanimesh]

Keeping this issue alive because duckdb doesn't work with windows msvc using C++ API.

[Mause]

Keeping this issue alive because duckdb doesn't work with windows msvc using C++ API.

This issue seems to be about MingW, not MSVC. We don't support MingW, but we definitely do support MSVC, as that's how we compile for Windows. If you're having an issue with MSVC, please create an issue with a full reproduction

[arnabanimesh]

I'll open another issue shortly using the latest stable release, but the original post in this thread is posted keeping msvc in mind and not mingw.

I tried building the example app with /utf-8 flag using latest stable msvc. It built successfully, but wouldn't show any output.

[Mause]

@arnabanimesh what do you mean "wouldn't show any output"?

[arnabanimesh]

I would do result -> print(); but it wouldn't show any output. Even normal cout in the first line of the program wouldn't print anything. Cout prints properly if I remove every line associated with duckdb.

…

On Sat, 16 Sept, 2023, 9:31 am Elliana May, ***@***.***> wrote: @arnabanimesh <https://github.com/arnabanimesh> what do you mean "wouldn't show any output"? — Reply to this email directly, view it on GitHub <#4144 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/ABOAZSBOZ3YRF7DB33SI2MLX2UQBXANCNFSM532EGLCA> . You are receiving this because you were mentioned.Message ID: ***@***.***>

[Mause]

I would do result -> print(); but it wouldn't show any output.

Even normal cout in the first line of the program wouldn't print anything. Cout prints properly if I remove every line associated with duckdb.

On Sat, 16 Sept, 2023, 9:31 am Elliana May, @.***>
wrote:

@arnabanimesh https://github.com/arnabanimesh what do you mean
"wouldn't show any output"?

—
Reply to this email directly, view it on GitHub
#4144 (comment),
or unsubscribe
https://github.com/notifications/unsubscribe-auth/ABOAZSBOZ3YRF7DB33SI2MLX2UQBXANCNFSM532EGLCA
.
You are receiving this because you were mentioned.Message ID:
@.***>

Can you provide a sample of the code you're running?

[arnabanimesh]

It works when I built the main branch on my system. C++ API doesn't work when using the 0.8.1 version.

[github-actions]

This issue is stale because it has been open 90 days with no activity. Remove stale label or comment or this will be closed in 30 days.

[github-actions]

This issue was closed because it has been stale for 30 days with no activity.