I am trying to validate if some text, which is json, before processing it further.

I am using the ISJSON function in SQL Server 2016.

I have a problem that some of my json is slightly malformed; it contains unescaped newline char, quotes and tabs. (I may also get some trailing commas as well, but these are less of a concern).

Json libraries in languages like C# are more forgiving and just transform/ignore these small errors.

Is there a way to allow ISJSON() to be less strict and accept unescaped newline, quote and tab chars?


Is there a way in SQL to check if some text is valid json; which is forgiving of unescaped newline, quotes and tab chars?


'[{"key1": "Some value",}]' -- Trailing comma

'[{"key1": "Some \value"}]' -- Unescaped backslash

'[{"key1": "Some value"}]' -- Unescaped tab

'[{"key1": "Some value"}]' -- Unescaped new line

  • 2
    What you are describing is incoming data issue that you need to fix before validating. There are no knobs that you can turn on to make isjson() less strict.
    – Kin Shah
    Nov 4, 2017 at 19:52
  • @Kin I agree. However all of the C# libraries I have tried will just transform/ignore these small errors; which is desirable in 99% of all cases. But in this case wont stop bad json getting trough to the DB and failing there. (This is an error we are having in production) Which I why I was looking to see if is a way to get ISJSON() to be more forgiving. ( I am also looking into finding a stricter parser upstream). Also due to the data provenance requirements I can't use C# (etc.) to transform the data prior to it landing in the DB. Any other suggestions gladly accepted. Nov 4, 2017 at 23:45


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