MySQL 按字段排序（列名，子查询）

Question

I'm trying to get data in order to display something like this:

db schema:

category_id	parent_category
banana	fruit
apple	fruit
kiwi	fruit
cucumber	vegetable
celery	vegetable
pork	meat
beef	meat
chicken	meat
t-shirt	clothes
jeans	clothes
sweater	clothes
meat	food
fruit	food
vegetable	food
food	null
clothes	null

select * from category 
order by 
field(category_id, "banana") desc,
field(parent_category, (SELECT parent_category FROM category WHERE category_id = "banana")) desc
field(category_id, (select category_id from category where parent_category <> (SELECT parent_category FROM category WHERE category_id = "banana"))) desc

my goal result is to display with following order:
banana first,
other kinds of fruits second,
other kinds of food third,
clothes last (all other data that are not considered as food.)
second and third level categories don't have to be displayed (meat, fruit, vegetable, t-shirt, jeans, sweater, food, clothes)

Answer 1

Perhaps something like this:

SELECT * FROM category 
 WHERE 
    IF(parent_category='food',NULL,parent_category) IS NOT NULL
ORDER BY
   CASE WHEN category_id='banana' THEN 1
        WHEN parent_category='fruit' THEN 2
        WHEN parent_category='clothes' THEN 99
        ELSE 3 END;

Using CASE expression in the ORDER BY section and filter out parent_category that is food and NULL . Result will be like this:

category_id	parent_category
banana	fruit
apple	fruit
kiwi	fruit
cucumber	vegetable
celery	vegetable
pork	meat
beef	meat
chicken	meat
t-shirt	clothes
jeans	clothes
sweater	clothes

Demo fiddle