Обсуждение: JDBC 3.0 support?
any target date for a JDBC3.0 compliant driver? -- ================================================================= = Management is doing things right; leadership is doing the = = right things. - Peter Drucker = =_______________________________________________________________= = http://www.sun.com/service/sunps/jdc/javacenter.pdf = = www.sun.com | www.javasoft.com | http://wwws.sun.com/sunone = =================================================================
The driver does support jdbc3.0. However that support is not 100% complete (but then neither is the jdbc2 nor jdbc1 support 100% either). So the real question is what isn't there that you are looking for? thanks, --Barry Hanasaki JiJi wrote: > any target date for a JDBC3.0 compliant driver?
primarily - ResultSet resultSet = statement.getGeneratedKeys(); Barry Lind wrote: > The driver does support jdbc3.0. However that support is not 100% > complete (but then neither is the jdbc2 nor jdbc1 support 100% either). > So the real question is what isn't there that you are looking for? > > thanks, > --Barry > > Hanasaki JiJi wrote: > >> any target date for a JDBC3.0 compliant driver? > > > > -- ================================================================= = Management is doing things right; leadership is doing the = = right things. - Peter Drucker = =_______________________________________________________________= = http://www.sun.com/service/sunps/jdc/javacenter.pdf = = www.sun.com | www.javasoft.com | http://wwws.sun.com/sunone = =================================================================
Hanasaki, The driver is already 3.0 compliant for that. It correctly returns false to DatabaseMetaData.supportsGetGeneratedKeys() indicating that postgresql does not support this functionality. This isn't likely to change unless some significant new functionality is introduced in the server to do this. There isn't really anything the driver can do here since the functionality doesn't exist in the database to automatically return this information. thanks, --Barry Hanasaki JiJi wrote: > primarily - ResultSet resultSet = statement.getGeneratedKeys(); > > Barry Lind wrote: > >> The driver does support jdbc3.0. However that support is not 100% >> complete (but then neither is the jdbc2 nor jdbc1 support 100% >> either). So the real question is what isn't there that you are >> looking for? >> >> thanks, >> --Barry >> >> Hanasaki JiJi wrote: >> >>> any target date for a JDBC3.0 compliant driver? >> >> >> >> >> >
Any suggestions for architecture/implemenation in the following situation:?
- insert a new row
- primary key is an autoinc / sequence column
- no other column is sure to be unique
- need to continue working with the data of the row
after the insert and possibly do an update
Barry Lind wrote:
> Hanasaki,
>
> The driver is already 3.0 compliant for that. It correctly returns
> false to DatabaseMetaData.supportsGetGeneratedKeys() indicating that
> postgresql does not support this functionality. This isn't likely to
> change unless some significant new functionality is introduced in the
> server to do this. There isn't really anything the driver can do here
> since the functionality doesn't exist in the database to automatically
> return this information.
>
> thanks,
> --Barry
>
Barry Lind <blind@xythos.com> writes:
> The driver is already 3.0 compliant for that. It correctly returns
> false to DatabaseMetaData.supportsGetGeneratedKeys() indicating that
> postgresql does not support this functionality. This isn't likely to
> change unless some significant new functionality is introduced in the
> server to do this.
What exactly would the server need to do to support this? Do you think
the effort is warranted?
regards, tom lane
Tom, This essentially would rely on the 'returning' functionality that has been discussed previously on hackers. Specifically the spec states that the database should return all 'auto generated keys' or specifically requested columns for inserted rows. However the proposals I have seen for 'returning' are done through a returning sql clause. This would mean the jdbc driver would need to parse the user supplied sql and insert the correct returning clause into the proper location in the sql statement. It also means that the driver would need a way to determine which columns were 'auto generated' (which shouldn't be too difficult for serial columns, but if the auto-generating mechanism was a trigger or a default clause, I am not sure how that would be done). Here is what the spec (http://java.sun.com/products/jdbc/download.html#corespec30) says: 13.6 Retrieving Auto Generated Keys Many database systems have a mechanism that automatically generates a unique key field when a row is inserted. The method Statement.getGeneratedKeys, which can be called to retrieve the value of such a key, returns a ResultSet object with a column for each automatically generated key. A flag indicating that any auto generated columns should be returned is passed to the methods execute, executeUpdate or prepareStatement when the statement is executed or prepared. Additional methods allow the ordinals or names of the columns that should be returned to be specified. Calling ResultSet.getMetaData on the ResultSet object returned by getGeneratedKeys will produce a ResultSetMetaData object that can be used to determine the number, type and properties of the generated keys. In some cases, such as in an insert select statement, more than one key may be returned. The ResultSet object returned by getGeneratedKeys will contain a row for each key that a statement generated. If no keys are generated, an empty result set will be returned. The concurrency of the ResultSet object returned by getGeneratedKeys must be CONCUR_READ_ONLY. The type of the ResultSet object must be either TYPE_FORWARD_ONLY or TYPE_SCROLL_INSENSITIVE. The method DatabaseMetaData.supportsGetGeneratedKeys returns true if a JDBC driver and underlying data source support the retrieval of automatically generated keys. thanks, --Barry Tom Lane wrote: > Barry Lind <blind@xythos.com> writes: > >>The driver is already 3.0 compliant for that. It correctly returns >>false to DatabaseMetaData.supportsGetGeneratedKeys() indicating that >>postgresql does not support this functionality. This isn't likely to >>change unless some significant new functionality is introduced in the >>server to do this. > > > What exactly would the server need to do to support this? Do you think > the effort is warranted? > > regards, tom lane >
INSERT .... RETURNING will work here, but in the meantime
select nextval('sequence_name');
insert into (id,....) values ( result from above, ....)
continue working
Dave
On Tue, 2003-05-06 at 23:13, Hanasaki JiJi wrote:
> Any suggestions for architecture/implemenation in the following situation:?
> - insert a new row
> - primary key is an autoinc / sequence column
> - no other column is sure to be unique
> - need to continue working with the data of the row
> after the insert and possibly do an update
>
> Barry Lind wrote:
> > Hanasaki,
> >
> > The driver is already 3.0 compliant for that. It correctly returns
> > false to DatabaseMetaData.supportsGetGeneratedKeys() indicating that
> > postgresql does not support this functionality. This isn't likely to
> > change unless some significant new functionality is introduced in the
> > server to do this. There isn't really anything the driver can do here
> > since the functionality doesn't exist in the database to automatically
> > return this information.
> >
> > thanks,
> > --Barry
> >
>
>
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> TIP 4: Don't 'kill -9' the postmaster
--
Dave Cramer <Dave@micro-automation.net>