Hi Dan,
If I said somewhere that Postgres supports TINYINT, then that was a big,
old lie. Perhaps my brain short-circuited and I meant the other open
source database I care about: MySQL. As you note, MySQL supports a
TINYINT datatype, intended to fit in a byte. I'm looking at a copy of
the MySQL Reference Manual version 5.0,3-alpha. Section 11.1.1 of that
manual gives both signed and unsigned ranges of the integer types.
Section 11.2 says that when declaring these types, you can specify an
extra UNSIGNED keyword to pick the unsigned range.
Sybase and Microsoft SQL Server, as you note, support the unsigned range
for TINYINT. It's interesting that all of the other integer types are
signed quantities. See
http://gsbwww.uchicago.edu/computing/research/SASManual/accdb/z0439559.htm
and
http://msdn.microsoft.com/library/default.asp?url=/library/en-us/tsqlref/ts_ia-iz_3ss4.asp.
So as you say, among database vendors TINYINT's range is not
standardized. This underscores Lance's point about the JDBC verbiage.
Cheers,
-Rick
Daniel John Debrunner wrote:
Rick Hillegas wrote:
I see this in section 8.3.4
"The JDBC type TINYINT represents an 8-bit integer value between 0 and
255 that may be signed or unsigned."
Hi Dan,
I don't mean to pile up on you after your jet lag. Welcome back!
I wasn't back, it's that three day in jet-lag, but thanks anyway!
I'm back now though. :-)
Yeah, that's the same sentence I saw. It's a bit oddly worded. The
"8-bit integer value" makes it sound like a byte. But "value between 0
and 255 that may be signed or unsigned" could mean a "value between
-256 and 255", that is, a 9-bit quantity. I'm putting my faith in the
8-bit part.
So it seems there would be two choices:
-128 to 127 :
+ matches JDBC 3.0 mapping to a byte (tables B.1/B.2)
- does not match SQL Server, Sybase
0 to 255 :
+ matches SQL Server, Sybase
- does not match JDBC 3.0 mapping to a byte
Hmmmm, that's kind of an awkward place to be in. It seems you want to
add this non-standard SQL type to match other databases, but by matching
the other databases you break the JDBC spec. :-)
MySQL seems to claim both ranges, but I didn't look to see how you
specifiy signed vs. unsigned. Given MySQL's type handling in other areas
I'm not sure they a a good "reference" implementation.
Rick, you also, I think, said in one e-mail that Postgres supports
TINYINT, I've only been able to find information that Postgres does not
support TINYINT, do you have a link?
Dan.
