>>>>By default all declared variables will be NULL. Assuming you will not be having NULL values in your XML file you can do
>>>>
>>>>update myTable SET Fld1Name = COALESCE(@Fld1Value, Fld1Name), etc.
>>>
>>>I didn't know that I can skip declaring a variable. I thought that I always have to do
>>>declare @MyVarName INT before using it.
>>>
>>>I have never used COALESCE() either. The approach you describe should work. I will test it.
>>>Thank you.
>>
>>This is not what I said. You can not skip DECLARE in SQL Server, all variables must be declared. Once a variable is declared, it will be NULL. The select @FidlVar = ...
>>doesn't change the value if that select statement returns 0 rows. So, if you never going to have NULL values passed in your XML, then the solution I suggested is the simplest one.
>>
>>The alternative is to build the dynamic SQL which is also simple.
>
>Just to clarify. The following will set the variable @MyVar to NULL?
>
>

>DECLARE @MyVar char(10)
>

>
>Correct?

Yes, correct. Simple test

SELECT @MyVar as WhatIAm