Kathey Marsden wrote:
Rick Hillegas wrote:
Hi Kathey,
My gut feeling is that changing this behavior could affect
applications like ij which make formatting decisions based on the
JDBC types of returned columns.
If you return the correct column type of the base type, then the
formatting would be correct.
I agree, but I am not sure yet how significant that impact might be.
I'd like translate it into exactly what JDBC calls will have different
behavior in order to more accurately assess the risk in typical usage
scenarios.
Certainly there are these changes for the ResultSet returned by
getGeneratedKeys():
o getMetaData() would correspond to the ResultSetMetadata of the
base table column and so will have different types, columnwidths etc,
so formatting and other decisions based on this information may be
affected.
Portable code would adjust accordingly to the correct width. This is
what a tool would do.
o getObject() would return a different type and applications making
casts based on the assumption it is a BigDecimal may see cast
exceptions or other problematic behavior because of this assumption.
Or because you are returning a BigDecimal when someone is not expecting
it, you also have problematic behavior. This fact is buried in the
Derby docs currently.
o getString() would return a different String representation which
might be problematic if a particular format was expected and parsed.
This would be bad user code if you depended on getString for a numeric
value of any type to be consistent.
Would other ResultSet methods might be affected? For instance, would
getInt(), getLong(), getShort() etc. all still work as they did
before and return the same values?
Of course there is the other question still outstanding:
Why would these methods be effected, they have nothing to do with this.
What usage cases would *benefit* from changing it? This is
important, because if there is no real benefit to changing it why
take the risk at all?
Well the issue is that this behavior is not expected that you are
returning a different data type then the column in the table.
Kathey
