protected function extractType($dbType)
{
if(strpos($dbType,'[')!==false || strpos($dbType,'char')!==false || strpos($dbType,'text')!==false)
$this->type='string';
else if(strpos($dbType,'bool')!==false)
$this->type='boolean';
else if(preg_match('/(real|float|double)/',$dbType))
$this->type='double';
else if(preg_match('/(integer|oid|serial|smallint)/',$dbType))
$this->type='integer';
else
$this->type='string';
}