Transform JSON column to string - sql-server-2016

Question

I have a script that selects data into an XML table with a single column and then converts that into a string:
(
SELECT N'DECLARE #' + REPLACE( COLUMN_NAME, ' ', '_' ) + #CrLf
FROM #TABLE
FOR XML PATH(''), TYPE
).value( '.', 'nvarchar(max)' ) + #CrLf +
I'm trying to do the same thing with JSON but I just can't seem to figure out the last part. I'm able to create a table with a single column but no matter what I try, I can't seem to get it to convert to a string:
(
SELECT ( N'DECLARE #' + REPLACE( COLUMN_NAME, ' ', '_' ) + #CrLf ) AS MyString
FROM #TABLE
FOR JSON PATH
)
Here is a testable sample (which includes the above):
DECLARE #CrLf nchar(2) = CHAR(13) + CHAR(10);
DECLARE #TABLE TABLE ( [COLUMN_NAME] sysname );
INSERT INTO #TABLE VALUES
( 'COL1' ),
( 'COL2' ),
( 'COL3' ),
( 'COL4' ),
( 'COL5' );
DECLARE #Script nvarchar(max) =
(
SELECT N'DECLARE #' + REPLACE( COLUMN_NAME, ' ', '_' ) + #CrLf
FROM #TABLE
FOR XML PATH(''), TYPE
).value( '.', 'nvarchar(max)' ) + #CrLf +
(
SELECT ( N'DECLARE #' + REPLACE( COLUMN_NAME, ' ', '_' ) + #CrLf ) AS MyString
FROM #TABLE
FOR JSON PATH
);
SELECT #Script;
It outputs the following:
XML Transform:
DECLARE #COL1
DECLARE #COL2
DECLARE #COL3
DECLARE #COL4
DECLARE #COL5
JSON Transform:
[{"MyString":"DECLARE #COL1\r\n"},{"MyString":"DECLARE #COL2\r\n"},{"MyString":"DECLARE #COL3\r\n"},{"MyString":"DECLARE #COL4\r\n"},{"MyString":"DECLARE #COL5\r\n"}]
So in closing, I'm trying to get the JSON Transform to look the same as the XML Transform does.
Much appreciated.

Answer 1

This should do it
DECLARE #TABLE TABLE ( [COLUMN_NAME] sysname );
INSERT INTO #TABLE VALUES
( 'COL1' ),
( 'COL2' ),
( 'COL3' ),
( 'COL4' ),
( 'COL5' );
DECLARE #json NVARCHAR(MAX) =
(
SELECT N'DECLARE #' + REPLACE( COLUMN_NAME, ' ', '_' ) AS MyString
FROM #TABLE
FOR JSON PATH
)
SELECT JSON_VALUE(value,'$.MyString') AS 'JSON Transform'
FROM OPENJSON(#json,'$')
Results
+--------------+
|JSON Transform|
+--------------+
| DECLARE #COL1|
| DECLARE #COL2|
| DECLARE #COL3|
| DECLARE #COL4|
| DECLARE #COL5|
+--------------+
This link you help you understand the OPENJSON and JSON_VALUE functions, JSON Path Expressions