Hi Thomas,
On Thu, Aug 19, 2010 at 5:35 AM, Thomas Mueller <
thomas.tom.muel...@gmail.com> wrote:
> Hi,
>
> I think it's somewhat unlogical (at least inconsistent) that a module
> doesn't have a name when you create it, but has a name when you drop
> it. I would prefer it having a name in both cases. The name doesn't
> need to match the class name.
>
I did start with naming the module at create time, but it seemed silly to
define a "name" in two places, eg:
CREATE MODULE WIBBLE AS
$$
import java.sql.*;
public class Wibble ....
...
$$
Is it desirable that module vs class name could be different? DON'T REPEAT
YOURSELF was shouting in my ear.
What name would you expect to use when used as part of, for example, "CREATE
TRIGGER" -- module or classname? If classname, then do you also want the
package name to be required? (Currently I've not got support for packages --
they go into the existing "org.h2.dynamic" package used for user-defined
classes)
CREATE TRIGGER TRIG_INS BEFORE INSERT ON TEST FOR EACH ROW CALL "WIBBLE"
<--- Am I calling a "module" or a "classname"?
Perhaps the classname is completely irrelevent -- we just use whatever class
we happen to find defined within the 'module'?
> You have used an unnamed package. Does this mean the package name can
> be specified in the source code. First I thought that's a bit
> dangerous, but it's probably not a problem (it's not a bigger security
> risk) and more logical that way.
>
As above -- I'm thinking that there doesn't need to be any support for
packages.
> By the way, did you see
> http://h2database.com/javadoc/org/h2/tools/TriggerAdapter.html ? It's
> very similar to SimpleTrigger - only it uses result sets instead of
> arrays.
I know TriggerAdapter well -- it's just that a ResultSet isn't very good at
letting you change values :-)
> Maybe we should add a second TriggerAdapter with arrays?
>
As you know, I support anything that reduces the code required to write a
simple trigger!
Cheers
Kerry
>
> Regards,
> Thomas
>
>
>
> On Thu, Aug 5, 2010 at 6:25 AM, Kerry Sainsbury <ke...@fidelma.com> wrote:
> > Hi Thomas,
> >
> > How do you like this example. It's very simple. Basically you copy and
> paste
> > Java code and call it a "MODULE". The class can then be called from
> whatever
> > wants it (and I can easily implement my simpler trigger idea just by
> putting
> > in a "SimpleTrigger" class that I can extend in another module. Note
> there
> > is no need to name a module, as we can just use the class name:
> >
> >
> > CREATE MODULE AS
> > $$
> > import java.sql.*;
> > import org.h2.api.Trigger;
> >
> > public abstract class SimpleTrigger implements Trigger {
> > public void init(Connection conn, String schemaName, String
> > triggerName, String tableName, boolean before, int type) throws
> SQLException
> > {
> > }
> > public abstract void fire(Connection conn, Object[] oldRow,
> > Object[] newRow) throws SQLException;
> > public void close() throws SQLException {
> > }
> > public void remove() throws SQLException {
> > }
> > }
> > $$
> >
> >
> > CREATE MODULE AS
> > $$
> > import java.sql.*;
> >
> > public class MyTrigger extends SimpleTrigger {
> > public void fire(Connection conn, Object[] oldRow, Object[]
> newRow)
> > throws SQLException {
> > newRow[0] = ((String)newRow[0]).toUpperCase();
> > }
> > }
> > $$
> >
> >
> > CREATE TRIGGER TRIG_INS BEFORE INSERT ON TEST FOR EACH ROW CALL
> "MyTrigger"
> >
> >
> > DROP TRIGGER TRIG_INS
> > DROP MODULE MyTrigger
> > DROP MODULE SimpleTrigger
> >
> >
> > What do you think?
> >
> > Cheers
> > Kerry
> >
> >
> >
> > On Thu, Jul 22, 2010 at 8:02 AM, Thomas Mueller
> > <thomas.tom.muel...@gmail.com> wrote:
> >>
> >> Hi,
> >>
> >> I think the
> >> CREATE CODE MyTriggerCode LANGUAGE JAVA FOR TRIGGER AS
> >> is very verbose. What about:
> >> CREATE TRIGGER ... AS?
> >> That's similar syntax as CREATE ALIAS ... AS.
> >>
> >> H2 only supports Java currently, so there is no reason to require
> >> "JAVA". Once other languages are supported it can still be added as an
> >> option.
> >>
> >> However I'm not sure if it makes sense to provide shortcut to directly
> >> register a trigger as source code *snippet* (that is, only the fire
> >> method). I think it's no problem to require the source code of the
> >> *complete* class in this case. If you write short static function,
> >> then the current CREATE ALIAS ... AS source is handy (I used it many
> >> times). But if you write a trigger, you anyway do that in the IDE,
> >> meaning you anyway have the source code of the complete class
> >> somewhere. Because you want to use auto-complete of the IDE, and so
> >> forth. Triggers are almost never as simple as a Java function.
> >>
> >> I think if we want to support CREATE CODE then this should be only
> >> used to add classes to the "internal classpath" of H2. Independent of
> >> for what those classes are used (trigger, aggregate, function
> >> alias,...), and therefore without any magic to adopt to the right type
> >> / add missing glue code. Even without automatically adding import
> >> statements. Those classes can then be used for many things. For
> >> example a class that contains multiple public static methods plus a
> >> trigger (or even multiple triggers using inner classes). Or it could
> >> even contain multiple classes, or a jar file (which would be stored in
> >> the database). Instead of CREATE CODE what about CREATE MODULE or
> >> CREATE LIBRARY? There could be a module / library for MySQL helper
> >> functions, for PostgreSQL helper functions, and so on. Like a Apache
> >> HTTP module. There should be an way to "auto-start", maybe using a
> >> method in the loaded library.
> >>
> >> Existing features could then be retro-fitted as modules / libraries.
> >> For example fulltext search.
> >>
> >> Regards,
> >> Thomas
> >>
> >> --
> >> You received this message because you are subscribed to the Google
> Groups
> >> "H2 Database" group.
> >> To post to this group, send email to h2-datab...@googlegroups.com.
> >> To unsubscribe from this group, send email to
> >> h2-database+unsubscr...@googlegroups.com<h2-database%2bunsubscr...@googlegroups.com>
> .
> >> For more options, visit this group at
> >> http://groups.google.com/group/h2-database?hl=en.
> >>
> >
> > --
> > You received this message because you are subscribed to the Google Groups
> > "H2 Database" group.
> > To post to this group, send email to h2-datab...@googlegroups.com.
> > To unsubscribe from this group, send email to
> > h2-database+unsubscr...@googlegroups.com<h2-database%2bunsubscr...@googlegroups.com>
> .
> > For more options, visit this group at
> > http://groups.google.com/group/h2-database?hl=en.
> >
>
> --
> You received this message because you are subscribed to the Google Groups
> "H2 Database" group.
> To post to this group, send email to h2-datab...@googlegroups.com.
> To unsubscribe from this group, send email to
> h2-database+unsubscr...@googlegroups.com<h2-database%2bunsubscr...@googlegroups.com>
> .
> For more options, visit this group at
> http://groups.google.com/group/h2-database?hl=en.
>
>
--
You received this message because you are subscribed to the Google Groups "H2
Database" group.
To post to this group, send email to h2-datab...@googlegroups.com.
To unsubscribe from this group, send email to
h2-database+unsubscr...@googlegroups.com.
For more options, visit this group at
http://groups.google.com/group/h2-database?hl=en.
