JSON path is not properly formatted. Unexpected character ‘#’ is found at position 2

SQL Server has a pretty good support for JSON. If there is a special character in JSON, then it will throw this error;

To produce this, here is an example

DECLARE @data NVARCHAR(50)='{"#Name":"Shahzad"}'

-- Print the current JSON
PRINT @data

-- Rename the key (by copying the value to a new key, then deleting the old one)
SET @data=
 JSON_MODIFY(
  JSON_MODIFY(@data,'$.Contractor', JSON_VALUE(@data,'$.#Name')),
  '$.#Name',
  NULL
 )
-- Print the new JSON
PRINT @data

I didn’t find any built-in support to handle these characters. The workaround I found is to simply replace special characters. Here is how;

DECLARE @data NVARCHAR(50)='{"#Name":"Shahzad"}'
DECLARE @cleanData NVARCHAR(50) = REPLACE(@data, '#Name', 'Name');
-- Print the current JSON
PRINT @data

-- Rename the key (by copying the value to a new key, then deleting the old one)
SET @cleanData=
 JSON_MODIFY(
  JSON_MODIFY(@cleanData,'$.Contractor', JSON_VALUE(@cleanData,'$.Name')),
  '$.Name',
  NULL
 )
-- Print the new JSON
PRINT @cleanData

And the output is;

{“#Name”:”Shahzad”}
{“Contractor”:”Shahzad”}

References

https://learn.microsoft.com/en-us/sql/t-sql/functions/json-modify-transact-sql?source=recommendations&view=sql-server-ver16

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