Querying json key name in SQL Server - sql-server

Question

Given json like this...
{"setting1":"A","setting2":"B","setting3":"C"}
I would like to see results like...
+----------+-------+
| name | value |
+----------+-------+
| setting1 | A |
| setting2 | B |
| setting3 | C |
+----------+-------+
My struggle is I'm trying to find out how to extract the key's name (i.e., "setting1", "setting2", "setting3", etc.)
I could do something like the following query, but I don't know how many settings there will be and what their names will be, so I'd like something more dynamic.
SELECT
B.name,
B.value
FROM OPENJSON(#json) WITH
(
setting1 varchar(50) '$.setting1',
setting2 varchar(50) '$.setting2',
setting3 varchar(50) '$.setting3'
) A
CROSS APPLY
(
VALUES
('setting1', A.setting1),
('setting2', A.setting2),
('setting3', A.setting3)
) B (name, value)
With XML, I could do something simple like this:
DECLARE #xml XML = '<settings><setting1>A</setting1><setting2>B</setting2><setting3>C</setting3></settings>'
SELECT
A.setting.value('local-name(.)', 'VARCHAR(50)') name,
A.setting.value('.', 'VARCHAR(50)') value
FROM #xml.nodes('settings/*') A (setting)
Any way to do something similar with SQL Server's json functionality?

Answer 1

Aaron Bertrand has written about json key value in Advanced JSON Techniques
SELECT x.[Key], x.[Value]
FROM OPENJSON(#Json, '$') AS x;
Return
Key Value
------------------
setting1 A
setting2 B
setting3 C

Answer 2

Option Using a Table
Declare #YourTable table (ID int,JSON_String varchar(max))
Insert Into #YourTable values
(1,'{"setting1":"A","setting2":"B","setting3":"C"}')
Select A.ID
,C.*
From #YourTable A
Cross Apply (values (try_convert(xml,replace(replace(replace(replace(replace(JSON_String,'"',''),'{','<row '),'}','"/>'),':','="'),',','" '))) ) B (XMLData)
Cross Apply (
Select Name = attr.value('local-name(.)','varchar(100)')
,Value = attr.value('.','varchar(max)')
From B.XMLData.nodes('/row') as C1(r)
Cross Apply C1.r.nodes('./#*') as C2(attr)
) C
Returns
ID Name Value
1 setting1 A
1 setting2 B
1 setting3 C
Option Using a String Variable
Declare #String varchar(max) = '{"setting1":"A","setting2":"B","setting3":"C"}'
Select C.*
From (values (try_convert(xml,replace(replace(replace(replace(replace(#String,'"',''),'{','<row '),'}','"/>'),':','="'),',','" '))) ) A (XMLData)
Cross Apply (
Select Name = attr.value('local-name(.)','varchar(100)')
,Value = attr.value('.','varchar(max)')
From A.XMLData.nodes('/row') as C1(r)
Cross Apply C1.r.nodes('./#*') as C2(attr)
) C
Returns
Name Value
setting1 A
setting2 B
setting3 C

Answer 3

If you are open to a TVF.
The following requires my Extract UDF. This function was created because I was tired of extracting string (patindex,charindex,left,right, etc). It is a modified tally parse which accepts two non-like delimiters.
Example
Declare #YourTable table (ID int,JSON_String varchar(max))
Insert Into #YourTable values
(1,'{"setting1":{"global":"A","type":"1"},"setting2":{"global":"B","type":"1"},"setting3":{"global":"C","type":"1"}} ')
Select A.ID
,B.Setting
,C.*
From #YourTable A
Cross Apply (
Select Setting = replace(replace(B1.RetVal,'"',''),'{','')
,B2.RetVal
From [dbo].[udf-Str-Extract](A.JSON_String,',',':{') B1
Join [dbo].[udf-Str-Extract](A.JSON_String,':{','}') B2
on B1.RetSeq=B2.RetSeq
) B
Cross Apply (
Select Name = C1.RetVal
,Value = C2.RetVal
From [dbo].[udf-Str-Extract](','+B.RetVal,',"','":') C1
Join [dbo].[udf-Str-Extract](B.RetVal+',',':"','",') C2
on C1.RetSeq=C2.RetSeq
) C
Returns
ID Setting Name Value
1 setting1 global A
1 setting1 type 1
1 setting2 global B
1 setting2 type 1
1 setting3 global C
1 setting3 type 1
The UDF if Interested
CREATE FUNCTION [dbo].[udf-Str-Extract] (#String varchar(max),#Delimiter1 varchar(100),#Delimiter2 varchar(100))
Returns Table
As
Return (
with cte1(N) As (Select 1 From (Values(1),(1),(1),(1),(1),(1),(1),(1),(1),(1)) N(N)),
cte2(N) As (Select Top (IsNull(DataLength(#String),0)) Row_Number() over (Order By (Select NULL)) From (Select N=1 From cte1 N1,cte1 N2,cte1 N3,cte1 N4,cte1 N5,cte1 N6) A ),
cte3(N) As (Select 1 Union All Select t.N+DataLength(#Delimiter1) From cte2 t Where Substring(#String,t.N,DataLength(#Delimiter1)) = #Delimiter1),
cte4(N,L) As (Select S.N,IsNull(NullIf(CharIndex(#Delimiter1,#String,s.N),0)-S.N,8000) From cte3 S)
Select RetSeq = Row_Number() over (Order By N)
,RetPos = N
,RetVal = left(RetVal,charindex(#Delimiter2,RetVal)-1)
From (
Select *,RetVal = Substring(#String, N, L)
From cte4
) A
Where charindex(#Delimiter2,RetVal)>1
)
/*
Max Length of String 1MM characters
Declare #String varchar(max) = 'Dear [[FirstName]] [[LastName]], ...'
Select * From [dbo].[udf-Str-Extract] (#String,'[[',']]')
*/