Wt

Namasthe,

On debugging I found that

Countries::const_iterator country

was not iterating on country; directive.

So the iterator was struck at a particular value. But strangely (country != countries.end()) was exiting after 246 loops as expected. That means the country value should have changed....bit puzzling....

I don't see how this isn't working for you.

This code works perfectly for me (Wt version 3.3.3)

@Wt::Dbo::collection<Wt::Dbo::ptr> files = session_.find();

Wt::Dbo::collection<Wt::Dbo::ptr>::const_iterator i = files .begin();

while(i != files.end())

{

std::cout << "Country: " << (*i)->size;

i;

}@

You are showing us your first 10 rows for the field: country_iso_3166_numeric_code

but you are iterating over the database and printing the field: country_iso_3166_a2_code

are you sure that country_iso_3166_a2_code field is not full of AF values?

Namasthe Alex,

The problem got worse now. I am getting exception !!

Here is my code:

int main(int argc, char **argv)

{

/*

• Setup a session, would typically be done once at application startup.
  */
  dbo::backend::MySQL sambhaashane("sambhaashane",
  "sambhaashane",
  "secret",
  "localhost",
  3306,
  "/var/run/mysql/mysql.sock");
  sambhaashane.setProperty("show-queries", "true");
  dbo::Session session;
  session.setConnection(sambhaashane);
  session.mapClass("country_iso_3166_tbl");
  dbo::Transaction transaction(session);

typedef Wt::Dbo::collection< dbo::ptr > Countries;

Countries countries = session.find();

bool flag = transaction.isActive();

{

Wt::Dbo::collection< dbo::ptr >::const_iterator country = countries.begin();

int index = 0;

while(country != countries.end())

{

std::cout << index

<< "] Country: "

<< (*country)->country_iso_3166_numeric_code

<< '\n';

country;

}

}

}

===

When I run, the output is:

start transaction

select "country_iso_3166_numeric_code", "country_iso_3166_a2_code", "country_iso_3166_a3_code", "country_name", "country_legal_name", "country_native_name", "currency_iso_4217_number_code", "country_calling_code", "country_internet_extension", "country_follows_dst" from "country_iso_3166_tbl"

terminate called after throwing an instance of 'Wt::Dbo::Exception'

what(): Dbo load(): no active transaction

Press to close this window...

I see that the tranasction_ variable is 0x0. Giving raise to above exception.

Here is additional info:

Linux : OpenSuse 13.1

Db: maria db : mysql Ver 15.1 Distrib 5.5.33-MariaDB, for Linux (i686) using readline 5.1

Boost: Boost 1_53_0

Wt: 3.3.3.

I downloaded boost and compiled it into /usr/local/lib/boost_1_53_0 directory

I downloaded wt 3.3.3 and compiled it into /usr/local/lib/wt_3_3_3 directory (linked to the above boost libs).

Please let me know where I am going wrong.

I have given the complete source code.

The country_iso_3166_tbl: Is fully populated with country information. there are no null cells in the table.

Regards

Rathna

Namasthe,

The session.transaction_ is 0x0 after the session.find<sambhaashane_country_iso_3166_orm>(); operation.

This is being checked in the countries.begin();

In the method:

template

void Session::implLoad(MetaDbo& dbo, SqlStatement *statement, int& column)

{

if (!transaction_)

throw Exception("Dbo load(): no active transaction");

LoadDbAction action(dbo, *getMapping(), statement, column);

C *obj = new C();

try {

action.visit(*obj);

dbo.setObj(obj);

} catch (...) {

delete obj;

throw;

}

}

the exception is "thrown"....

What is the issue here... Please help me resolve this.

Regards

Rathna

It appears that you do not have an active transaction.

read the Wt::Dbo tutorial

http://www.webtoolkit.eu/wt/doc/tutorial/dbo/tutorial.html

Namasthe,

I have already published the entire code.... Please have a look at it.

The code snippet is here:

Wt::Dbo::Session session;

session.setConnection(sambhaashane);

session.mapClass("country_iso_3166_tbl");

Wt::Dbo::Transaction transaction(session);

{

typedef Wt::Dbo::collection< dbo::ptr > Countries;

Countries countries = session.find();

bool flag = transaction.isActive();

as you cansee....I have started the transaction ...as per the wt::dbo tutorial.

Still I get an exception.... please let me know why?

I m struck. Please help me.

Regards

Rathna

Hey,

 dbo::id(a,country_iso_3166_numeric_code,"country_iso_3166_numeric_code");
 dbo::field(a, country_iso_3166_numeric_code,    "country_iso_3166_numeric_code");

You need to remove the 'field()' : you are mapping the same field twice, once as a id, and a second time as plain field.

I'm not sure how that confuses Wt::Dbo though, but it might.

I cannot explain why you would be getting a 'no transaction active' exception though.

Regards,

koen

Namasthe

I am using wt 3.3.3 version. I think there is a problem lurking in the wt dbo section. The transaction_ variable is not getting updated. It stays at 0x0, thus throwing an exception.

I have attached the screen shots. I have highlighted the transaction_ value.

Kindly help to fix the issue asap.

Regards

Rathna

Any solution found by anybody..

Please help.

Regards

Rathna

Hi,

Is all of the code that you pasted above in the same function?

Can you submit a full example that demonstrates the problem?

BR,

Wim.

I am uploading all the files including the .pro that i use to build.

Please let me know the error source.

Regards

Rathna

Hey,

I tried your test case, but that works without any problem for me. I modified your test case to also add a data record, and to use SQlite3 instead of MySQL (because I do not have a MySQL on this computer now actually), see attached.

test.wt 
begin transaction
create table "country_iso_3166_tbl" (
  "country_iso_3166_numeric_code" integer not null,
  "country_iso_3166_a2_code" text not null,
  "country_iso_3166_a3_code" text not null,
  "country_name" text not null,
  "country_legal_name" text not null,
  "country_native_name" text not null,
  "currency_iso_4217_number_code" integer not null,
  "country_calling_code" integer not null,
  "country_internet_extension" text not null,
  "country_follows_dst" boolean not null,
  primary key ("country_iso_3166_numeric_code")
)
commit transaction
begin transaction
insert into "country_iso_3166_tbl" ("country_iso_3166_numeric_code", "country_iso_3166_a2_code", "country_iso_3166_a3_code", "country_name", "country_legal_name", "country_native_name", "currency_iso_4217_number_code", "country_calling_code", "country_internet_extension", "country_follows_dst") values (?, ?, ?, ?, ?, ?, ?, ?, ?, ?)
commit transaction
begin transaction
select "country_iso_3166_numeric_code", "country_iso_3166_a2_code", "country_iso_3166_a3_code", "country_name", "country_legal_name", "country_native_name", "currency_iso_4217_number_code", "country_calling_code", "country_internet_extension", "country_follows_dst" from "country_iso_3166_tbl" 
0] Country: 40
commit transaction

I suspect you have some build inconsistency: are you using the same compiler (e.g. C+11 versus C+03) and are you not by any chance having multiple versions of Wt and mixing include/libraries?

Does the modified example work correctly for you?

Koen

Hi,

I know this is an old post but I am experiencing the same problem than Rathna. It is very frustrating as the wt dbo library seems very interesting (I am using it but without iteration on dbo collection). I use sqlite3 on ubuntu, with the last Wt version from github repository.

I tried several things and I ended up by checking the building consistency, as suggested by Koen. But I am not sure I checked properly, it is a bit out of my skill. I have multiple version of Wt but apperently my app is using the proper one. Does anyone has a solution for this issue? I can share my code, but as Koen tested the code of Rathna and have not reproduced the bug on its computer, I suppose it is not usefull to share the code right now.

Jo

Hello Jonathan,

sharing code is always useful. You set-up is slightly different. I would appreciate a minimal example, so that I can try to reproduce the issue.

Hi Matthias,

Here is a reproductible example:

header.h

#ifndef HEADER_H
#define HEADER_H
#include <sqlite3.h>
#include <map>
#include <string>
#include <Wt/Dbo/Dbo.h>
#include <Wt/Dbo/backend/Sqlite3.h>

#pragma GCC diagnostic ignored "-Wunused-function"
#pragma GCC diagnostic ignored "-Wreorder"

namespace dbo = Wt::Dbo;
using namespace std;

class caracteristiqueCS{
public:
    caracteristiqueCS():zbio(0),station_id(0),VCP(0),SES(0),SCC(0),RCS(0),PB(0),tass_sol(0),N2000(""),N2000_maj(""),Wal(""),Wal_maj(""){}
    int VCP,SES,SCC,RCS,PB,tass_sol;
    int zbio,station_id;
    std::string Wal,Wal_maj,N2000,N2000_maj;
    template<class Action>
    void persist(Action& a)
    {
        dbo::field(a, zbio,     "zbio");
        dbo::field(a, station_id, "station_id");
        dbo::field(a, VCP,     "VCP");
        dbo::field(a, SES,    "SES");
        dbo::field(a, SCC,    "SCC"); //sensibilité aux changement climatique, plus de microclimat
        dbo::field(a, RCS,    "RCS");
        dbo::field(a, PB,    "PB");
        dbo::field(a, Wal,    "Wal");
        dbo::field(a, Wal_maj,    "Wal_maj");
        dbo::field(a, N2000,    "N2000");
        dbo::field(a, N2000_maj,    "N2000_maj");
        dbo::field(a, tass_sol,    "tass_sol");
    }
    caracteristiqueCS(const caracteristiqueCS * c):zbio(c->zbio),station_id(c->station_id),VCP(c->VCP),SES(c->SES),SCC(c->SCC),RCS(c->RCS),PB(c->PB),Wal(c->Wal),Wal_maj(c->Wal_maj),N2000(c->N2000),N2000_maj(c->N2000_maj),tass_sol(c->tass_sol){}
private:
};

class cdicoAptBase : public std::enable_shared_from_this<cdicoAptBase>
{
public:
    cdicoAptBase(std::string aBDFile);
    void closeConnection();
    int openConnection();

protected:
    std::string mBDpath;
    sqlite3 **db_;
    sqlite3 * ptDb_;
    std::map<std::pair<int,int>,caracteristiqueCS> Dico_US2KK;
};

#endif // HEADER_H

main.cpp

#include <iostream>
#include "header.h"

int main()
{
    cout << "Hello World!" << endl;
    cdicoAptBase *dico=new cdicoAptBase("/home/jo/app/Forestimator/carteApt/data/aptitudeEssDB.db");

    return 0;
}

cdicoAptBase::cdicoAptBase(std::string aBDFile):mBDpath(aBDFile),ptDb_(NULL)
{
    db_=&ptDb_;

    if (openConnection()){
        std::cout << " bd pas ouverte!!!\n"<< std::endl;
    } else {

        /* This first part is using slite3 without Wt */

        sqlite3_stmt * stmt;
        std::string SQLstring="SELECT Ess_FR,Code_FR,prefix, FeRe FROM dico_essences ORDER BY Ess_FR DESC;";
        sqlite3_prepare_v2( *db_, SQLstring.c_str(), -1, &stmt, NULL );//preparing the statement
        while(sqlite3_step(stmt) == SQLITE_ROW)
        {
            if (sqlite3_column_type(stmt, 0)!=SQLITE_NULL && sqlite3_column_type(stmt, 1)!=SQLITE_NULL){
                std::string aNomEs=std::string( (char *)sqlite3_column_text( stmt, 0 ) );
                std::string aCodeEs=std::string( (char *)sqlite3_column_text( stmt, 1 ) );
                std::string aPrefix=std::string( (char *)sqlite3_column_text( stmt, 2 ) );
                /* I do what i want with the result*/
            }
        }

        sqlite3_finalize(stmt);

        closeConnection();

        /* Here I use Wt:dbo */
        std::unique_ptr<dbo::backend::Sqlite3> sqlite3{new dbo::backend::Sqlite3(mBDpath)};
        Wt::Dbo::Session session;
        session.setConnection(std::move(sqlite3));
        session.mapClass<caracteristiqueCS>("caracteristiqueCS");
        dbo::Transaction transaction{session};

        // first iteration without collection (working properly)

        for (int us(1);us <18;us++){
            dbo::ptr<caracteristiqueCS>  pt = session.find<caracteristiqueCS>().where("zbio = ?").bind(1).where("station_id = ?").bind(us);
            // I create a copy of caracteristiqueCS because I am not at ease with the dbo::ptr system
            caracteristiqueCS  kkCSCopy(pt.get());
            std::cout <<"caracteristiqueCS id: " << kkCSCopy.station_id <<  std::endl;
            Dico_US2KK.emplace(std::make_pair(std::make_pair(kkCSCopy.zbio,kkCSCopy.station_id),kkCSCopy));
        }

         std::cout << "second iteration with collection"<<  std::endl;

        // test collection and iteration on element of collection
        typedef dbo::collection< dbo::ptr<caracteristiqueCS> > collectionKKCS;
        collectionKKCS col = session.find<caracteristiqueCS>().where("zbio = ?").bind(1);

        std::cout << "collection size " << col.size() << std::endl;

        dbo::collection<dbo::ptr<caracteristiqueCS>>::const_iterator i = col.begin();
        while(i != col.end())
        {
            std::cout << "caracteristiqueCS id: " << (*i)->station_id<<  std::endl;
            i++;
        }

        // third iteration without collection
         std::cout << "a last run"<< std::endl;

        for (int us(1);us <18;us++){
            dbo::ptr<caracteristiqueCS>  pt = session.find<caracteristiqueCS>().where("zbio = ?").bind(1).where("station_id = ?").bind(us);
            // I create a copy of caracteristiqueCS because I am not at ease with the dbo::ptr system
            caracteristiqueCS  kkCSCopy(pt.get());
            std::cout <<"caracteristiqueCS id: " << kkCSCopy.station_id <<  std::endl;
            Dico_US2KK.emplace(std::make_pair(std::make_pair(kkCSCopy.zbio,kkCSCopy.station_id),kkCSCopy));
        }
    }
}

void cdicoAptBase::closeConnection(){
    int rc = sqlite3_close(*db_);
    if( rc ) {
        fprintf(stderr, "Can't close database: %s\n\n\n", sqlite3_errmsg(*db_));
    }
}

int cdicoAptBase::openConnection(){
    int rc;
    rc = sqlite3_open(mBDpath.c_str(), db_);
    if( rc!=0) {
        fprintf(stderr, "Can't open database: %s\n", sqlite3_errmsg(*db_));
        std::cout << " mBDpath " << mBDpath << std::endl;
        std::cout << "result code : " << rc << std::endl;
    }
    return rc;
}

below the content of the table caracteristiqueCS

zbio;station_id;VCP;SES;SCC;RCS;PB;Wal;Wal_maj;N2000;N2000_maj;tass_sol
1;1;4;4;4;1;1;G1.51;G1.51;91D0*;91D0*;1
1;2;3;4;4;1;2;G1.41b, G1.52;G1.41b;;;1
1;3;4;3;3;1;2;G1.81;G1.81;9190;9190;1
1;4;4;3;1;2;2;G1.81;G1.81;9190;9190;2
1;5;3;2;3;2;3;G1.61, G1.87a;G1.61;9110;9110;2
1;6;4;4;4;2;2;G1.212, G1.211;G1.212;91E0*;91E0*;1
1;7;4;4;4;2;4;G1.212, G1.A1ca;G1.A1ca;91E0*, 9160;9160;2
1;8;3;3;4;3;4;G1.A1ca, G1.61, G1.87a, G1.63a;G1.61;9110, 9130, 9160;9110;2
1;9;4;4;4;1;3;G1.A41a, G1.A41b, G1.A41c;G1.A41b;9180*;9180*;4
1;10;3;3;1;1;2;G1.87a, G1.87b;G1.87a;;;4
1;11;3;3;2;2;3;G1.61, G1.87a, G1.A1cb;G1.61;9160, 9110;9110;3
1;12;3;3;3;2;3;G1.87a, G1.61;G1.61;9110;9110;3
1;13;4;3;4;3;4;G1.61, G1.63a, G1.A1ca;G1.61;9130, 9110, 9160;9110;2
1;14;3;2;4;3;4;G1.61, G1.87a;G1.61;9110;9110;2
1;15;3;2;3;3;3;G1.87a, G1.61;G1.61;9110;9110;3
1;16;3;2;2;2;2;G1.87a, G1.61;G1.87a;;;4
1;17;4;3;1;1;1;;;;;4

I use Qt as IDE and here is my config file (.pro) which is used by qmake (instead of cmake)

TEMPLATE = app
CONFIG += console c++11
CONFIG -= app_bundle
CONFIG -= qt

TARGET = test
INCLUDEPATH += .
QT -= gui
QT += sql

CONFIG += c++17

LIBS = -lwthttp -lwt -lboost_system -lboost_iostreams  -lboost_filesystem -lboost_program_options -lwtdbo -lwtdbosqlite3 -lsqlite3


SOURCES += \
        main.cpp

HEADERS += \
    header.h
---------------------------------------

a few additionnal info:
g++ --version
g++ (Ubuntu 9.4.0-1ubuntu1~20.04.2) 9.4.0

ldd test
linux-vdso.so.1 (0x00007ffda9bf0000)
libwtdbo.so.4.10.2 => /usr/local/lib/libwtdbo.so.4.10.2 (0x00007f52f35ad000)
libwtdbosqlite3.so.4.10.2 => /usr/local/lib/libwtdbosqlite3.so.4.10.2 (0x00007f52f34c3000)
libsqlite3.so.0 => /lib/x86_64-linux-gnu/libsqlite3.so.0 (0x00007f52f339a000)
libstdc++.so.6 => /lib/x86_64-linux-gnu/libstdc++.so.6 (0x00007f52f31b8000)
libgcc_s.so.1 => /lib/x86_64-linux-gnu/libgcc_s.so.1 (0x00007f52f319d000)
libc.so.6 => /lib/x86_64-linux-gnu/libc.so.6 (0x00007f52f2fab000)
libdl.so.2 => /lib/x86_64-linux-gnu/libdl.so.2 (0x00007f52f2fa3000)
libpthread.so.0 => /lib/x86_64-linux-gnu/libpthread.so.0 (0x00007f52f2f80000)
libm.so.6 => /lib/x86_64-linux-gnu/libm.so.6 (0x00007f52f2e31000)
/lib64/ld-linux-x86-64.so.2 (0x00007f52f3679000)

and eventually... the output of the code in the terminal:

Hello World!
caracteristiqueCS id: 1
caracteristiqueCS id: 2
caracteristiqueCS id: 3
caracteristiqueCS id: 4
caracteristiqueCS id: 5
caracteristiqueCS id: 6
caracteristiqueCS id: 7
caracteristiqueCS id: 8
caracteristiqueCS id: 9
caracteristiqueCS id: 10
caracteristiqueCS id: 11
caracteristiqueCS id: 12
caracteristiqueCS id: 13
caracteristiqueCS id: 14
caracteristiqueCS id: 15
caracteristiqueCS id: 16
caracteristiqueCS id: 17
second iteration with collection
collection size 17
caracteristiqueCS id: 1
caracteristiqueCS id: 1
caracteristiqueCS id: 1
caracteristiqueCS id: 1
caracteristiqueCS id: 1
caracteristiqueCS id: 1
caracteristiqueCS id: 1
caracteristiqueCS id: 1
caracteristiqueCS id: 1
caracteristiqueCS id: 1
caracteristiqueCS id: 1
caracteristiqueCS id: 1
caracteristiqueCS id: 1
caracteristiqueCS id: 1
caracteristiqueCS id: 1
caracteristiqueCS id: 1
caracteristiqueCS id: 1
a last run
caracteristiqueCS id: 1
caracteristiqueCS id: 1
caracteristiqueCS id: 1
caracteristiqueCS id: 1
caracteristiqueCS id: 1
caracteristiqueCS id: 1
caracteristiqueCS id: 1
caracteristiqueCS id: 1
caracteristiqueCS id: 1
caracteristiqueCS id: 1
caracteristiqueCS id: 1
caracteristiqueCS id: 1
caracteristiqueCS id: 1
caracteristiqueCS id: 1
caracteristiqueCS id: 1
caracteristiqueCS id: 1
caracteristiqueCS id: 1

Thank you in advance for your help, it is much appreciated!
Jo

And the archive with all needed files;

I am still having trouble with DBO collection, so any advice would be greatly appreciated.
Jonathan