Re: CHANGING DATA TYPE

"Savas Ates" <in da club> schrieb 
Dim xx As SqlClient.SqlDataReader

I take values from my db by appliying that method. ? 


How do you intend to handle Null values coming from the database? You can
not store them in a string. Declare the variable As Object.

   dim ProductPropertyValues_Value as object

   ProductPropertyValues = xx("ProductPropertyValues_Value")

Later, if you want to distinguish between Null and String, you have to
write:


   if ProductPropertyValues_Value is dbnull.value then
       'handle null value
   else
       'handle string
   end if



- OR -

Some people convert DBNull to Nothing in order to be able to declare the
variable As String:

   Dim ProductPropertyValues_Value as string
   dim o as object

   o = xx("ProductPropertyValues_Value")

   if o is dbnull.value then
       ProductPropertyValues_Value = Nothing
   else
       ProductPropertyValues_Value = o.ToString
   end if

Later usage:
   if ProductPropertyValues_Value is nothing then
       '...
   else
       '...
   end if

Later, if you want to save the values back to the database, you have to
convert back from Nothing to DBNull.Value.


Typed datasets, or classes that you create on your own, can have typed
members (As String) that simplifies this (because the member is typed), and
they have additional "IsMemberNull" and "SetMemberNull" methods.


Armin

.

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