使用 WITHOUT_ARRAY_WRAPPER 返回奇数数据的 JSON 子查询？

Question

SQL Server 2016，我正在尝试处理一些常规数据并返回一个 JSON 对象以供另一个系统处理。另一个系统无法识别数组包装器，因此我尝试使用 WITHOUT_ARRAY_WRAPPER 来摆脱它。在子查询中使用时会返回奇怪的结果...

SELECT @@SERVERNAME AS [Servername],
( SELECT [Name], [Recovery_Model_Desc]  
    FROM sys.databases
    WHERE name in ('master', 'model', 'msdb')
    FOR JSON PATH
    ) AS d
FOR JSON PATH, ROOT('ServerInformation')

这会产生预期的数据，使用数组包装器......

{"ServerInformation":[{"Servername":"MyServer","d":[{"Name":"master","Recovery_Model_Desc":"SIMPLE"},{"Name":"model","Recovery_Model_Desc" :"FULL"},{"Name":"msdb","Recovery_Model_Desc":"SIMPLE"}]}]}

但是， WITHOUT_ARRAY_WRAPPER 产生...

SELECT @@SERVERNAME AS [Servername],
( SELECT [Name], [Recovery_Model_Desc]  
    FROM sys.databases
    WHERE name in ('master', 'model', 'msdb')
    FOR JSON PATH, WITHOUT_ARRAY_WRAPPER
    ) AS d
FOR JSON PATH, ROOT('ServerInformation')

{"ServerInformation":[{"Servername":"MyServer","d":"{\"Name\":\"master\",\"Recovery_Model_Desc\":\"SIMPLE\"},{\"Name \":\"model\",\"Recovery_Model_Desc\":\"FULL\"},{\"Name\":\"msdb\",\"Recovery_Model_Desc\":\"SIMPLE\"}"}] }

而我希望它产生

{"ServerInformation":{"Servername":"MyServer","d":{"Name":"master","Recovery_Model_Desc":"SIMPLE"},{"Name":"model","Recovery_Model_Desc":" FULL"},{"Name":"msdb","Recovery_Model_Desc":"SIMPLE"}}}

错误或预期结果？

编辑：调整预期结果

Answer 1

使用 json_query,

SELECT @@SERVERNAME AS [Servername],
json_query(( SELECT [Name], [Recovery_Model_Desc]  
    FROM sys.databases
    WHERE name in ('master', 'model', 'msdb')
    FOR JSON PATH, WITHOUT_ARRAY_WRAPPER
    ) ) AS d
FOR JSON PATH, ROOT('ServerInformation')

Answer 2

引入该功能时有一篇博客文章说：

如果您想要单个对象，则需要在脚本中添加WITHOUT_ARRAY_WRAPPER，[...]WITHOUT_ARRAY_WRAPPER不会生成有效的JSON文本，[...]将把NestedJson视为任何其他纯文本转义它并用双引号括起来。

这篇文章本身有点混乱和破碎，但我对此的解读是，它仅用于单行结果，因此嵌套 JSON 将被视为字符串。