/**
* The recursive function that will return the actual SQL string from a group.
*
* @param DatasetWhereClause $group
* @return string
*/
private function _parseWhereClause(DatasetWhereClause $group){
$statements = $group->getStatements();
$ws = [];
foreach($statements as $w){
if($w instanceof DatasetWhereClause){
// Recursively recurring recursion, RECURSE!
$str = $this->_parseWhereClause($w);
if($str){
$ws[] = '( ' . $str . ' )';
}
}
elseif($w instanceof DatasetWhere){
// No field, what can I do?
if(!$w->field) continue;
$op = $w->op;
// Null values should be IS NULL or IS NOT NULL, no sanitizing needed.
if($w->value === null){
$v = 'NULL';
// NULL also has a fun trick with mysql.... = and != doesn't work :/
if($op == '=') $op = 'IS';
elseif($op == '!=') $op = 'IS NOT';
}
elseif($w->value === 1){
// (int)1 is used sometimes to describe enum(1).
$v = "'1'";
}
elseif($w->value === 0){
// (int)0 is used sometimes to describe enum(0).
$v = "'0'";
}
// Numbers are allowed with no sanitizing, they're just numbers.
elseif(is_int($w->value)){
$v = $w->value;
}
// IN statements allow an array to be passed in. Check the values in the array and wrap them with parentheses.
elseif(is_array($w->value) && $op == 'IN'){
$vs = [];
foreach($w->value as $bit){
$vs[] = "'" . $this->_conn->real_escape_string($bit) . "'";
}
$v = '( ' . implode(',', $vs) . ' )';
}
else{
$v = "'" . $this->_conn->real_escape_string($w->value) . "'";
}
$ws[] = '`' . $w->field . '` ' . $op . ' ' . $v;
}
}
return implode(' ' . $group->getSeparator() . ' ', $ws);
}
