Postgre Group由json数组列

Question

我很难理解postgres json数组类型。如何使用json数组列进行组。例如：

select product, avg(sales)
from Order 
group by product

"Error: could not identify an equality operator for type json"

--Order--
id | sales | product                 
1  | 36    | ["874746", "474657"] 
2  | 120   | ["874748"] 
3  | 15    | ["874736", "474654"] 

Answer 1

您需要使用jsonb（二进制）9.4 +：

select product::jsonb, avg(sales)
from Order 
group by product::jsonb