return table from C++

[gugu15]

Hello guys!
I'm building a interface with SQLITE3 and Lua on the otclient. But I want return a table with the results of the SELECT for use in Lua.
A table like:

local selected = db:exec("SELECT * FROM PERSON")
--[
what I wanted:
selected = {{name = "Scot", age = 18, id = 1}, {name = "Louis", age = 21, id = 2}}
]]

I do not know how to do a function in c ++ to return a lua table

This is my code if somebody needs

//header
#ifndef __SQLAPI_H__
#define __SQLAPI_H__


#include <sqlite3.h>
#include "sqlitedeclaration.h"
#include <framework/luaengine/luaobject.h>
#include <framework/luaengine/luainterface.h>

class DatabaseSqlite : public LuaObject
{

public:
  static int callback(void *data, int argc, char **argv, char **columnName);
  bool exec(const std::string& query);
  bool open(const std::string& name);
  void onExec(std::string column, std::string value, int count, int total);
  void close();

protected:
  sqlite3 *database;
};

#endif

#include "sqlapi.h"


int DatabaseSqlite::callback(void *p, int argc, char **argv, char **columnName){
  DatabaseSqlite* pthis = (DatabaseSqlite*)(p);

  for(int i = 0; i<argc; i++){
      pthis->onExec(std::string(columnName[i]), std::string(argv[i] ? argv[i] : "NULL"), i+1, argc);
  }
  return 0;
}

void DatabaseSqlite::onExec(std::string column, std::string value, int count, int total){
  callLuaField("onExec", column, value, count, total);
}

bool DatabaseSqlite::exec(const std::string& query){
  char *errorMsg = 0;
  int ret;

  ret = sqlite3_exec(database, query.c_str(), DatabaseSqlite::callback, (void*)this, &errorMsg);
  if (ret == SQLITE_OK){
    return true;
  }else{
    sqlite3_free(errorMsg);
    return false;
  }
}

bool DatabaseSqlite::open(const std::string& name){ // .db name file is the paramter
    int ret;
    ret = sqlite3_open(name.c_str(), &database);
    if (ret == SQLITE_OK){
        return true;
    }else{
        return false;
    }
}


void DatabaseSqlite::close(){
    sqlite3_close(database);
}

Running:

 

[4drik]

Stackoverflow said:
Here's a quick helper function to push strings to the table:

void l_pushtablestring(lua_State* L , char* key , char* value) {
    lua_pushstring(L, key);
    lua_pushstring(L, value);
    lua_settable(L, -3);
}

Here is the helper function to create the table and pass it to a function:

// create a lua function
luaL_loadstring(L, "function fullName(t) print(t.fname,t.lname) end");
lua_pcall(L, 0, 0, 0);

// push the function to the stack
lua_getglobal(L, "fullName");

// create a table in c (it will be at the top of the stack)
lua_newtable(L);
l_pushtablestring(L, "fname", "john");
l_pushtablestring(L, "lname", "stewart");

// call the function with one argument
lua_pcall(L, 1, 0, 0);

You can also do the same for lua_pushnumber, but that's probably obvious.

Kind regards,
Adrik

 

[gugu15]

Thank you so much, I'll try make that

Edit:
I got it!
I saw the callLuaField code and lua_pushvalue code and made this code:

void DatabaseSqlite::onExec(std::vector<std::string> &columns, std::vector<std::string> &values){
  //callLuaField("onExec", columns, values);

  g_lua.pushObject(asLuaObject());
  g_lua.getField("onExec");
  if(!g_lua.isNil()){
    g_lua.insert(-2);
    g_lua.createTable(0, columns.size());
    for(int i = 0; i < columns.size(); i++){
      g_lua.pushString(values[i]);
      g_lua.setField(columns[i]);
    }
    g_lua.signalCall(1+1);
  }else{
    g_lua.pop(2);
  }
}