pgsReferenceGen::pgsReferenceGen(pgsThread * app, const wxString & table,
const wxString & column, const bool & sequence, const long & seed) :
pgsObjectGen(seed), m_app(app), m_table(table), m_column(column),
m_sequence(sequence)
{
// We need an empty symbol table for calling pgsExecute.eval(...)
pgsVarMap vars;
// Count the number of lines in the table
pgsOperand result = pgsExecute(wxString() << wxT("SELECT count(*) FROM ")
<< m_table, 0, m_app).eval(vars);
wxASSERT(result->is_record());
wxString value = result->value();
if (!value.IsEmpty())
{
m_nb_rows = pgsMapm::pgs_str_mapm(result->number().value());
}
else
{
m_nb_rows = 0;
}
wxLogScriptVerbose(wxT("REFGEN: Number of rows in %s: %s"), m_table.c_str(),
pgsMapm::pgs_mapm_str(m_nb_rows).c_str());
// Create an integer generator with that number of lines
m_randomizer = pgsRandomizer(pnew pgsIntegerGen(0, m_nb_rows - 1,
is_sequence(), m_seed));
}
pgsOperand pgsGenReference::eval(pgsVarMap &vars) const
{
// Evaluate parameters
pgsOperand table(m_table->eval(vars));
pgsOperand column(m_column->eval(vars));
pgsOperand sequence(m_sequence->eval(vars));
pgsOperand seed(m_seed->eval(vars));
// Check parameters and create the generator
if (table->is_string() && !table->value().IsEmpty() && column->is_string()
&& !column->value().IsEmpty() && sequence->is_integer()
&& seed->is_integer())
{
// Check wheter the table and the column do exist
pgsOperand result = pgsExecute(wxString() << wxT("SELECT 1 FROM ")
<< table->value() << wxT(" WHERE ") << column->value()
<< wxT(" = ") << column->value(), 0, m_app).eval(vars);
if (result->pgs_is_true())
{
long aux_sequence, aux_seed;
sequence->value().ToLong(&aux_sequence);
seed->value().ToLong(&aux_seed);
return pnew pgsGenerator(pgsVariable::pgsTString,
pnew pgsReferenceGen(m_app, table->value(),
column->value(), aux_sequence != 0, aux_seed));
}
else
{
throw pgsParameterException(wxString() << value()
<< wxT(":\ntable/column does not exist"));
}
}
else
{
// Deal with errors
if (!table->is_string() || table->value().IsEmpty())
{
throw pgsParameterException(wxString() << value()
<< wxT(":\ntable should be a non-empty string"));
}
else if (!column->is_string() || column->value().IsEmpty())
{
throw pgsParameterException(wxString() << value()
<< wxT(":\ncolumn should be a non-empty string"));
}
else if (!sequence->is_integer())
{
throw pgsParameterException(wxString() << value()
<< wxT(":\nsequence should be an integer"));
}
else
{
throw pgsParameterException(wxString() << value()
<< wxT(":\nseed should be an integer"));
}
}
}
wxString pgsReferenceGen::random()
{
// We need an empty symbol table for calling pgsExecute.eval(...)
pgsVarMap vars;
// Choose one line
pgsOperand result = pgsExecute(wxString() << wxT("SELECT ") << m_column
<< wxT(" FROM ") << m_table << wxT(" LIMIT 1 OFFSET ")
<< m_randomizer->random(), 0, m_app).eval(vars);
wxASSERT(result->is_record());
// Return the result as a single value
return dynamic_cast<const pgsRecord &>(*result).get(0, 0)->value();
}
pgsExpression *pgsExecute::clone() const
{
return pnew pgsExecute(*this);
}