m_array.AddKey(PR_ID); //primary key
m_array.AddColumn(PR_CREATIONDATE, t_("Creation Date"), 10)
    .SetConvert(Single<ConvertYourIntBasedDate>());
...
m_array.AddColumn(COM_NAME, t_("Company Name"), 10);
...

SqlSet GetSqlColumns(const ArrayCtrl &a_array)
{
	SqlSet cols;
	for(int i = 0; i < a_array.GetIndexCount(); i++)
		if(!a_array.GetId(i).IsNull())
			cols.Cat(SqlId(a_array.GetId(i)));
	return cols;
}

SqlSet cols = GetSqlColumns(m_array);
Sql sql;
sql * ::Select(Distinct(cols))
	.From(PROJECT)
	.LeftJoin(COMPANY)
	.On(COM_ID == PR_COMPANYID)
	.Where(1)
	.OrderBy(PR_ID)
;

for(;;) {
	Vector<Value> row;
	if(!sql.Fetch(row)) break;
	m_array.Add(row);
}

struct ConvCompany : Convert
{
        Value Format(const Value &q) const
        {
			SQL * Select(COM_NAME).From(COMPANY).Where(COM_ID == q);
			String company;
			if(SQL.Fetch())
				company = SQL[COM_NAME];
			else
				company = "";
			return q.IsNull() ? Null : company;
        }
};

.....
.....

projects.AddColumn(VPR_COMPANYID, t_("Customer")).SetConvert(Single<ConvCompany>());

projects.SetTable(PROJECTV),Leftjoined(COMPANY,VPR_COMPANYID),AS_PREFIX(VCOM_);
projects.AddColumn(VCOM_COMPANYNAME, t_("Customer"));

struct NameConvert : Convert {
	VectorMap<int, String> name;
	VectorMap<int, String> surname;
	virtual Value Format(const Value& q) const;
	void LoadAttrs();
};

Value NameConvert::Format(const Value& q) const
{
	return surname.Get(q, String()) + ' ' + name.Get(q, String());
}

void NameConvert::LoadAttrs()
{
	name.Clear();
	surname.Clear();
	Sql sql;
	sql * Select(SUBJECT_ID, ATTR, TEXT).From(SUBJECT_ATTR)
	      .OrderBy(Descending(Nvl(TILL, Date::High())));
	while(sql.Fetch()) {
		int sid = sql[SUBJECT_ID];
		String id = sql[ATTR];
		if(id == "NAME" && name.Find(sid) < 0)
			name.Add(sid, sql[TEXT]);
		if(id == "LASTNAME" && surname.Find(sid) < 0)
			surname.Add(sid, sql[TEXT]);
	}
}