Sql Parent Child Query

Query 1:[Update Query]
UPDATE categories
SET parent_id = (
    SELECT id FROM (SELECT id, name FROM categories) c
    WHERE c.name=categories.parent_name
)
WHERE parent_name IS NOT NULL



Query 2:[Select Query]
SELECT tbl_category.parentid FROM 
     (SELECT categoryid FROM tbl_category 
           WHERE categoryname='budgets') c,tbl_category
      WHERE c.categoryid=tbl_category.parentid


Query 3:[Select Query]
SELECT tbl_category.categoryid FROM tbl_category JOIN tbl_category c 
where c.categoryid=tbl_category.parentid and c.categoryname='states';

Query 4:[Yii Select Join Query]
        $categorymodel=Category::model()->with(array(
            'parent'=>array(
            'select'=>'categoryname',
            'joinType'=>'INNER JOIN',
            'condition'=>'parent.categoryname="'.$parentname.'"',
        ),
        ))->findAll();