[SQL] inserting string instead of values in dynamic SQL

I am trying to log parameter of SP in catch block, I have created dynamic string for parameter however when it insert into table it insert the string instead of value of parameter. below is my code.

DECLARE @ErrorMessage VARCHAR(4000),
@ErrorSeverity INT,
@ErrorState INT,
@ErrorProcedure VARCHAR(200),
@ErrorLine INT,
@ErrorNumber INT,
@ErrorParams VARCHAR(MAX)='';

-- Get the error information
SET @ErrorMessage = ERROR_MESSAGE();
SET @ErrorSeverity = ERROR_SEVERITY();
SET @ErrorState = ERROR_STATE();
SET @ErrorProcedure = ERROR_PROCEDURE();
SET @ErrorLine = ERROR_LINE();
SET @ErrorNumber = ERROR_NUMBER();

DECLARE @SPParameter AS TABLE (Id INT IDENTITY PRIMARY KEY, ParaName VARCHAR(100))
INSERT INTO @SPParameter (ParaName)
SELECT [name]
FROM sys.parameters
WHERE OBJECT_ID = OBJECT_ID(@ErrorProcedure)

DECLARE @minId INT, @maxId INT
SELECT @minId = MIN(Id),@maxId = MAX(Id) FROM @SPParameter

SET @ErrorParams = ''''

WHILE @minId <= @maxId
BEGIN
SELECT @ErrorParams = @ErrorParams + ''+ParaName+' = ''+ISNULL(CAST('+CAST(ParaName AS varchar)+' AS VARCHAR),'''')+'', '
FROM @SPParameter WHERE Id=@minId
SET @minId = @minId + 1
END

SET @ErrorParams = LEFT(@ErrorParams, LEN(@ErrorParams) - 2)

SET @ErrorParams = @ErrorParams + ''''''

INSERT INTO ErrorLog (ErrorMessage, ErrorSeverity, ErrorState, ErrorProcedure, ErrorLine, ErrorNumber, ErrorParams)
VALUES (@ErrorMessage, @ErrorSeverity, @ErrorState, @ErrorProcedure, @ErrorLine, @ErrorNumber, @ErrorParams);



It is inserting string i have created dynamically. below is the string which is inserting into my log table

'@Param1 = '+ISNULL(CAST(@Param1 AS VARCHAR),'')+', @Param2 = '+ISNULL(CAST(@Param2 AS VARCHAR),'')+', @Param3 = '+ISNULL(CAST(@Param3 AS VARCHAR),'')+', @Param4 = '+ISNULL(CAST(@Param4 AS VARCHAR),''

Continue reading...