is null with parameters

• Chris Chilvers

  SSCrazy

  Points: 2260

  More actions

  January 3, 2007 at 8:45 am

  #193564

  I keep getting the following error when trying to test if a parameter is null:

    Message="The specified argument value for the function is not valid. [ Argument # = 1,Name of function(if known) = isnull ]"

    HResult=-2147217900

    NativeError=25922

  Is it not possible to test if a parameter is null?

  What I'm trying to do is something like: (standard optimistic concurrency)

  UPDATE ... SET field = @field

  WHERE ...

  AND (field is null AND @old_field is null OR field = @old_field)

  Also, is it possible to set the values of parameters in management studio when testing some of these queries?

• Chris Chilvers

  SSCrazy

  Points: 2260

  More actions

  January 4, 2007 at 8:45 am

  #681233

  It seems that checking if a parameter is null is not supported by SQL Mobile.

  Also SQL Mobile doesn't support timestamps.

  Thus the only two simple solutions I can think of were:

  Having a column which is always set to newid() on any insert/update, just be sure that you always update it.

  Having a column which is set to getdate() on any insert/update, again be sure to always update it. This would not be as effective in high concurrency where two updates could occur at the same time, but on a mobile device this is less likely.

  In my case the use of the concurrency checks is just for sanity to make sure a different part of the progam doesn't try to commit a stale copy of a row (this shouldn't happen and is an error anyway).