SQL Server FOR JSON Path Nested Array

问题

We are trying to use FOR JSON Path in SQL Server 2016 for forming a Nested Array from a SQL Query.

SQL Query:

SELECT A, 
B.name as [child.name],
B.date as [child.date]
 from Table 1 join Table 2 on Table 1.ID=Table 2.ID FOR JSON PATH

Desired Output:

[{
A:"text",
   "child:"[
         {"name":"value", "date":"value"},
         {"name":"value", "date":"value"}

       ]
}]

However what we are getting is:

 [{
    A:"text",
    "child:" {"name":"value", "date":"value"}
  },
{
   A:"text",
  "child":{"name":"value", "date":"value"}
}]

How can we use FOR JSON PATH to form nested child array.

回答1:

instead of join use nested query, e.g.:

SELECT A
     , child=(
           SELECT B.name as [child.name]
                , B.date as [child.date] 
           FROM Table 2
           WHERE Table 2.ID = Table 1.ID 
           FOR JSON PATH
       )
from Table 1 FOR JSON PATH

(the query in the question is broken af so this query is just as broken but should give you the idea)

来源：https://stackoverflow.com/questions/45746718/sql-server-for-json-path-nested-array