What data type does the SQLCommand method ExecuteScalar() return?

Question

In SQL Server, ID is a not null integer, and an identity.

When I run the following code, I get an InvalidCastException on the last line:

SqlCommand         


        

Answer 1

It's probably returning a boxed instance of a different numeric type, such as long.
A boxed long cannot be converted to int.

You can call GetType() on the return value to see what type it really is.