MySQL Inner Join mit null Spalten

Question

Angenommen, ich habe 2 Tabellen

Table a 
brand Fruit   edible color size 
farmers banana  yes  yellow null 
fresh banana  yes  red  10 
bounty banana  null  green 2 
farmers apple   yes  red  5 
organic grapes  null  violet 5 
love  strawberry yes  null 5 
flow  lavander  no  null null 

Table b 
boxId fruit  edible color size 
10100 banana  yes  yellow 9 
19299 banana  yes  red  10 
10992 apple  yes  red  5 
10299 grapes  yes  red  5 
01929 lavander no  violet 3 

ist es möglich, Tabelle a und b auch mit der Regel zu verbinden, die: wenn es Nullwerte sind, weiterhin die verbleibenden Spalten Auswertung durch das Auslassen Nullspalte

select a.brand, b.boxId from a prod 
inner join b box on a.fruit = b.fruit 
where a.edible = b.edible and 
a.color = b.color and 
a.size = b.size 

brand  boxID 
farmers  10100 
fresh  19299 
. . . 

Answer 1

Ja wie diese

select a.brand, b.boxId 
from a prod 
inner join b box on a.fruit = b.fruit 
where (a.edible = b.edible OR a.edible IS NULL OR b.edible IS NULL) and 
     (a.color = b.color OR a.color IS NULL OR b.color IS NULL) and 
     (a.size = b.size OR a.size IS NULL OR b.size IS NULL) 

Answer 2

Try this:

select a.brand,b.boxId from 
(select a.brand,a.Fruit,a.edible,a.color,a.size from prod) as a 
inner join 
(select * from box) as b 
on a.fruit = b.fruit 
where a.color is not null and a.edible is not null and a.size is not null 
and b.color is not null and b.edible is not null and b.size is not null