MySQL how to select into JSON ARRAY

Question

in MySQL 5.7 we have the JSON_ARRAY object. I'd like to perform something similar to a SELECT GROUP_CONCAT(field) but with the results into a JSON_ARRAY.

My current query is:

SELECT GROUP_CONCAT(name) FROM users;

result: john,michael,sofia

I'd like the result to be: ["john","michael","sofia"]

My current solution is:

select @j:=json_array_append(@j,'$',name) from users

But that's very inefficient since it's re-calculated for every row. Is it possible to achieve that more efficiently?

Answer 1

You can use JSON_ARRAY to achieve what you want :

SELECT JSON_ARRAY(GROUP_CONCAT(name SEPARATOR ',')) AS names FROM users;

Like this it will let you obtain the desired result without having to re-calculate for each row.

Answer 2

You can use JSON_ARRAYAGG Example here:

https://github.com/AndreyMashukov/mysql-json-serializer