base on this table, how to get the expected output mysql php? - php

Question

It is kind of challenge. The expected output, all fruits are from ny or ak state and if the mark good=price 10 and bad= price 20 and OK= price 40. So, apple from ny state, have mark good and bad match the price 10 and 20, and apple don't have mark OK row, so no need to compare that. Banana mark bad = price 20, but OK is not equal price 40, so I will rule out banana. pear match OK = price 40 and state=ny and no rows of good and bad mark. Therefore, my output should be apple and pear. How should I do that?
<?php
/*
fruit state price mark
apple ny 10 good
apple ny 20 bad
banana ny 20 bad
banana ny 30 OK
pear ny 40 OK
berry pa 10 good
*/
/*this is my best query but fail to do what I expected*/
SELECT fruit FROM table WHERE state IN ('ny','ak') AND mark IN ('good', 'bad', 'OK') AND price IN ( '10','20','40') GROUP BY fruit
?>

Answer 1

you should where and or condition
You should use a pair of not in
select distinct fruit from my_table
where fruit not in (select distinct fruit from my_table
where (mark, price) not in (select 'good', 10 from dual
union
select 'bad, 20 from dual
union
select 'OK', 40 from dual))
state IN ('ny','ak') ;

Answer 2

The list of potential fruit that could be returned, because a row matches the specification:
SELECT t.fruit
FROM `table` t
WHERE t.state IN ('ny','ak')
AND ( ( t.mark = 'good' AND t.price = 10 )
OR ( t.mark = 'bad' AND t.price = 20 )
OR ( t.mark = 'OK' AND t.price = 40 )
)
GROUP BY t.fruit
A list of fruit that we don't want to return, because there is a row that doesn't satisfy the specification:
SELECT t.fruit
FROM `table` t
WHERE t.state IN ('ny','ak')
AND NOT ( t.mark = 'good' AND t.price = 10 )
AND NOT ( t.mark = 'bad' AND t.price = 20 )
AND NOT ( t.mark = 'OK' AND t.price = 40 )
GROUP BY t.fruit
Note that this will also include rows where the mark column has a value other than good, bad or OK. If we want to ignore rows with other values of mark, then we'd add...
AND t.mark IN ('good','bad','OK')
That gives us two sets. We can combine those with an antijoin operation. As an example of what that looks like, if we had tables fruit_to_include and fruit_to_exclude ...
SELECT i.fruit
FROM fruit_to_include i
LEFT
JOIN fruit_to_exclude e
ON e.fruit = i.fruit
WHERE e.fruit IS NULL
ORDER BY i.fruit
We can replace those placeholder table names with inline views, using the queries that give us the fruit to include and fruit to exclude. The only difference here is replacing the dummy table name with (what MySQL refers to as) derived table.
SELECT i.fruit
FROM -- fruit_to_include
( SELECT t.fruit
FROM `table` t
WHERE t.state IN ('ny','ak')
AND ( ( t.mark = 'good' AND t.price = 10 )
OR ( t.mark = 'bad' AND t.price = 20 )
OR ( t.mark = 'OK' AND t.price = 40 )
)
GROUP BY t.fruit
) i
LEFT
JOIN -- fruit_to_exclude
( SELECT r.fruit
FROM `table` r
WHERE r.state IN ('ny','ak')
AND r.mark IN ('good','bad','OK')
AND NOT ( r.mark = 'good' AND r.price = 10 )
AND NOT ( r.mark = 'bad' AND r.price = 20 )
AND NOT ( r.mark = 'OK' AND r.price = 40 )
GROUP BY r.fruit
) e
ON e.fruit = i.fruit
WHERE e.fruit IS NULL
ORDER BY i.fruit