public function prepareValueAndOperator($value, $operator, $useDefault = false)
{
if ($useDefault) {
return [$operator, '='];
} elseif ($this->invalidOperatorAndValue($operator, $value)) {
throw new InvalidArgumentException('Illegal operator and value combination.');
}
return [$value, $operator];
}
In this example you cannot execute a WHERE condition on a NULL value:
->where('price', '<=', $fPrice)