private function addOneValue($oneValue)
{
// check if all $keys are strings
foreach ($oneValue as $key => $value) {
if (!is_string($key)) {
throw new Exception('INSERT query: All keys of value array have to be strings.');
}
}
if (!$this->firstValue) {
$this->firstValue = $oneValue;
}
if (!$this->columns) {
$this->columns = array_keys($oneValue);
}
if ($this->columns != array_keys($oneValue)) {
throw new Exception('INSERT query: All VALUES have to same keys (columns).');
}
$this->statements['VALUES'][] = $oneValue;
}