SQL Server

JSON Escape and Unescape a String

Demonstrates how to JSON escape or unescape a string. SQL Server

--
CREATE PROCEDURE ChilkatSample
AS
BEGIN
    DECLARE @hr int
    DECLARE @sTmp0 nvarchar(4000)
    DECLARE @sb int
    EXEC @hr = sp_OACreate 'Chilkat.StringBuilder', @sb OUT
    IF @hr <> 0
    BEGIN
        PRINT 'Failed to create ActiveX component'
        RETURN
    END

    DECLARE @success int
    EXEC sp_OAMethod @sb, 'Append', @success OUT, 'backslash: \\, A: \u0041'
    EXEC sp_OAMethod @sb, 'GetAsString', @sTmp0 OUT
    PRINT @sTmp0

    --  The output is:
    --     backslash: \\, A: \u0041

    --  The keyword "json" can be used
    --  to escape and unescape.  To escape is to encode.  To unescape is to decode.

    --  Unescape (decode) the string in sb.
    EXEC sp_OAMethod @sb, 'Decode', @success OUT, 'json', 'utf-8'
    EXEC sp_OAMethod @sb, 'GetAsString', @sTmp0 OUT
    PRINT @sTmp0

    --  After JSON unescaping:
    --     backslash: \, A: A

    --  Now JSON escape the string.
    EXEC sp_OAMethod @sb, 'Encode', @success OUT, 'json', 'utf-8'
    EXEC sp_OAMethod @sb, 'GetAsString', @sTmp0 OUT
    PRINT @sTmp0

    --  After JSON escaping:
    --     backslash: \\, A: A

    --  Note: The "A" is not escaped to "\u0041" because there is no need.
    --  The "\uXXXX" format would be produced for non-printable control chars.

    EXEC @hr = sp_OADestroy @sb


END
GO