Convert two columns into key-value json object?

Question

Using FOR JSON AUTO or FOR JSON PATH on the following record set (which representing a product\'s attributes):

attribute | value
------         


        

Answer 1

Instead of JSON functions of SQL Server 2016, I used string concatenation function string_agg in SQL Server 2017 as seen in following script

/*create table ProductAttributes (
    product int,
    attribute varchar(40),
    value varchar(40)
)
insert into ProductAttributes select 1, 'color', 'red'
insert into ProductAttributes select 1, 'size', 'small'
insert into ProductAttributes select 2, 'processor', 'intel'
insert into ProductAttributes select 2, 'ram', '16'
insert into ProductAttributes select 2, 'weight', '2'*/

select 
    product, '{' + STRING_AGG( '"' + attribute + '":"' + STRING_ESCAPE(value,'json') + '"' ,',') + '}' as attributes
from ProductAttributes 
group by product

Output is as follows for the two product entries product attributes 1 {"color":"red","size":"small"} 2 {"processor":"intel","ram":"16","weight":"2"}

If you are using a previous version than SQL Server 2017, you can use string concatenation using SQL XML Path as follows

SELECT
    product,
  '{' + STUFF(
    (
    SELECT
      ',' + '"' + attribute + '":"' + STRING_ESCAPE(value,'json') + '"'
    FROM ProductAttributes a
        where a.product = p.product
    FOR XML PATH(''),TYPE
    ).value('.','VARCHAR(MAX)'
    ), 1, 1, ''
  ) + '}' As attributes
from ProductAttributes p
group by product

Developers will get the same result

I've updated above SQL queries and used String_Escape() function @Eilert's comment