Re: [Lift] Re: Single Table Inheritance
This is actually fairly common that messages Naftoli sends are empty, or don't
get threaded onto the original discussion, or formatting comes out funny.
Naftoli, what email client are you using?
-Ross
On Feb 5, 2010, at 1:49 AM, Mads Hartmann wrote:
Hey Naftoli,
I think something might have broken your first message, It's a blank
message if you view it through the web-interface:
http://groups.google.com/group/liftweb/browse_thread/thread/e2317e5dbaad4a65
If you have a solution I would love to hear it :)
On Feb 5, 1:52 am, Naftoli Gugenheim naftoli...@gmail.com wrote:
Does my approach not work?
-
Mads Hartmannmads...@gmail.com wrote:
Yeah that helped, my lab and scientist now looks like this:
/--- code
trait BaseSourceTrait[ T :BaseSourceTrait[T] ] extends
LongKeyedMapper[T] {
self: T =
override def primaryKeyField = id
object id extends MappedLongIndex(this)
object name extends MappedPoliteString(this, 256)
object sourceType extends MappedEnum(this,SourceTypes)
object SourceTypes extends Enumeration {
val Scientist = Value(Scientist)
val Lab = Value(Lab)
}
}
class Scientist extends BaseSourceTrait[Scientist] {
def getSingleton = Scientist
object birth extends MappedInt(this)
object death extends MappedInt(this)
object nationality extends MappedPoliteString(this, 128)
}
object Scientist extends Scientist with LongKeyedMetaMapper[Scientist]
{
override def dbTableName = Source
}
class Lab extends BaseSourceTrait[Lab] {
def getSingleton = Lab
object institution extends MappedLongForeignKey(this, Institution)
}
object Lab extends Lab with LongKeyedMetaMapper[Lab] {
override def dbTableName = Source
}
/--- code ends
My only problem now is that I can't figure out how to implement the
following:
A Discovery (a mapped class) needs to have a foreign key to the source
that made the discovery, this could be either a lab or a scientist, so
normally i would have a field with a reference to the super-class of
both Scientist and Lab - However, I don't have a super-class, I just
have a trait :)
I would like to be able to write something like this:
/--- code starts again
class Discovery extends LongKeyedMapper[Discovery] with IdPK {
def getSingleton = Discovery
// primatives
object description extends MappedDateTime(this)
object year extends MappedInt(this)
object reference extends MappedPoliteString(this, 128)
// relationships
object source extends MappedLongForeignKey(this, BaseSourceTrait) //
-- this is what i want.
}
object Discovery extends Discovery with LongKeyedMetaMapper[Discovery]
/--- code ends
As always I truely appreciate the help you guys are giving me :)
Thanks,
Mads Hartmann Jensen
On Feb 4, 9:56 pm, David Pollak feeder.of.the.be...@gmail.com wrote:
Please take a look at the MegaProtoUser and MegaMetaProtoUser code for
examples of how to create traits that can be mixed into classes.
Does that help?
On Thu, Feb 4, 2010 at 9:58 AM, Mads Hartmann Jensen
mads...@gmail.comwrote:
hello Jeppe,
In my project I've got the following three models: A discovery, a Scientist
and a lab. The Discovery has been invented by someone, this is either a
single scientist or sometimes a lab - This is easily done through
inheritance (would create a superclass named source) but I'm not sure how
to
do this so it maps nicely to the database.
Scientist and Lab only share one attribute so what I'm most interested in
is to be able express that a Discovery has s source that can be either a
lab
or scientist :)
Hope this explains my problem more clearly, thanks for the help
Mads Hartmann
Sent from my iPhone
On 04/02/2010, at 18.17, Jeppe Nejsum Madsen je...@ingolfs.dk wrote:
Mads Hartmann mads...@gmail.com writes:
Hello Everyone,
I'm currently trying to figure out how to map objects with inheritance
using the Mapper framework. I've got a Lab and a Scientist who inherit
from Source.
As I understand there's no direct way to do inheritance using the
Mapper framework so I'm trying to figure out how to implement 'Single
Table Inheritance'.
Right now I'm trying to create a single trait (Source) for the values
that they share called BaseSource and my idea is to mix it in both Lab
and Scientist. I would then define the table name of both scientist
and lab to be the same - I think this would work but what I'm not sure
of is the following:
- If both Scientist and Lab mixes in the IdPK trait and use the same
table, will the id still be unique?
- A Discovery has a source, how do i create MappedLongForeignKey
Re: [Lift] Re: Single Table Inheritance
Peek -- www.getpeek.com
Please forward any bad messages to feedb...@getpeek.com
-
Ross Mellgrendri...@gmail.com wrote:
This is actually fairly common that messages Naftoli sends are empty, or don't
get threaded onto the original discussion, or formatting comes out funny.
Naftoli, what email client are you using?
-Ross
On Feb 5, 2010, at 1:49 AM, Mads Hartmann wrote:
Hey Naftoli,
I think something might have broken your first message, It's a blank
message if you view it through the web-interface:
http://groups.google.com/group/liftweb/browse_thread/thread/e2317e5dbaad4a65
If you have a solution I would love to hear it :)
On Feb 5, 1:52 am, Naftoli Gugenheim naftoli...@gmail.com wrote:
Does my approach not work?
-
Mads Hartmannmads...@gmail.com wrote:
Yeah that helped, my lab and scientist now looks like this:
/--- code
trait BaseSourceTrait[ T :BaseSourceTrait[T] ] extends
LongKeyedMapper[T] {
self: T =
override def primaryKeyField = id
object id extends MappedLongIndex(this)
object name extends MappedPoliteString(this, 256)
object sourceType extends MappedEnum(this,SourceTypes)
object SourceTypes extends Enumeration {
val Scientist = Value(Scientist)
val Lab = Value(Lab)
}
}
class Scientist extends BaseSourceTrait[Scientist] {
def getSingleton = Scientist
object birth extends MappedInt(this)
object death extends MappedInt(this)
object nationality extends MappedPoliteString(this, 128)
}
object Scientist extends Scientist with LongKeyedMetaMapper[Scientist]
{
override def dbTableName = Source
}
class Lab extends BaseSourceTrait[Lab] {
def getSingleton = Lab
object institution extends MappedLongForeignKey(this, Institution)
}
object Lab extends Lab with LongKeyedMetaMapper[Lab] {
override def dbTableName = Source
}
/--- code ends
My only problem now is that I can't figure out how to implement the
following:
A Discovery (a mapped class) needs to have a foreign key to the source
that made the discovery, this could be either a lab or a scientist, so
normally i would have a field with a reference to the super-class of
both Scientist and Lab - However, I don't have a super-class, I just
have a trait :)
I would like to be able to write something like this:
/--- code starts again
class Discovery extends LongKeyedMapper[Discovery] with IdPK {
def getSingleton = Discovery
// primatives
object description extends MappedDateTime(this)
object year extends MappedInt(this)
object reference extends MappedPoliteString(this, 128)
// relationships
object source extends MappedLongForeignKey(this, BaseSourceTrait) //
-- this is what i want.
}
object Discovery extends Discovery with LongKeyedMetaMapper[Discovery]
/--- code ends
As always I truely appreciate the help you guys are giving me :)
Thanks,
Mads Hartmann Jensen
On Feb 4, 9:56 pm, David Pollak feeder.of.the.be...@gmail.com wrote:
Please take a look at the MegaProtoUser and MegaMetaProtoUser code for
examples of how to create traits that can be mixed into classes.
Does that help?
On Thu, Feb 4, 2010 at 9:58 AM, Mads Hartmann Jensen
mads...@gmail.comwrote:
hello Jeppe,
In my project I've got the following three models: A discovery, a Scientist
and a lab. The Discovery has been invented by someone, this is either a
single scientist or sometimes a lab - This is easily done through
inheritance (would create a superclass named source) but I'm not sure how
to
do this so it maps nicely to the database.
Scientist and Lab only share one attribute so what I'm most interested in
is to be able express that a Discovery has s source that can be either a
lab
or scientist :)
Hope this explains my problem more clearly, thanks for the help
Mads Hartmann
Sent from my iPhone
On 04/02/2010, at 18.17, Jeppe Nejsum Madsen je...@ingolfs.dk wrote:
Mads Hartmann mads...@gmail.com writes:
Hello Everyone,
I'm currently trying to figure out how to map objects with inheritance
using the Mapper framework. I've got a Lab and a Scientist who inherit
from Source.
As I understand there's no direct way to do inheritance using the
Mapper framework so I'm trying to figure out how to implement 'Single
Table Inheritance'.
Right now I'm trying to create a single trait (Source) for the values
that they share called BaseSource and my idea is to mix it in both Lab
and Scientist. I would then define the table name of both scientist
and lab to be the same - I think this would work but what I'm not sure
of is the following:
- If both
[Lift] Re: Single Table Inheritance
Naftoli would you please re-post your solution :) I could really use
the help
On Feb 5, 6:56 pm, Naftoli Gugenheim naftoli...@gmail.com wrote:
Peek --www.getpeek.com
Please forward any bad messages to feedb...@getpeek.com
-
Ross Mellgrendri...@gmail.com wrote:
This is actually fairly common that messages Naftoli sends are empty, or
don't get threaded onto the original discussion, or formatting comes out
funny. Naftoli, what email client are you using?
-Ross
On Feb 5, 2010, at 1:49 AM, Mads Hartmann wrote:
Hey Naftoli,
I think something might have broken your first message, It's a blank
message if you view it through the web-interface:
http://groups.google.com/group/liftweb/browse_thread/thread/e2317e5db...
If you have a solution I would love to hear it :)
On Feb 5, 1:52 am, Naftoli Gugenheim naftoli...@gmail.com wrote:
Does my approach not work?
-
Mads Hartmannmads...@gmail.com wrote:
Yeah that helped, my lab and scientist now looks like this:
/--- code
trait BaseSourceTrait[ T :BaseSourceTrait[T] ] extends
LongKeyedMapper[T] {
self: T =
override def primaryKeyField = id
object id extends MappedLongIndex(this)
object name extends MappedPoliteString(this, 256)
object sourceType extends MappedEnum(this,SourceTypes)
object SourceTypes extends Enumeration {
val Scientist = Value(Scientist)
val Lab = Value(Lab)
}
}
class Scientist extends BaseSourceTrait[Scientist] {
def getSingleton = Scientist
object birth extends MappedInt(this)
object death extends MappedInt(this)
object nationality extends MappedPoliteString(this, 128)
}
object Scientist extends Scientist with LongKeyedMetaMapper[Scientist]
{
override def dbTableName = Source
}
class Lab extends BaseSourceTrait[Lab] {
def getSingleton = Lab
object institution extends MappedLongForeignKey(this, Institution)
}
object Lab extends Lab with LongKeyedMetaMapper[Lab] {
override def dbTableName = Source
}
/--- code ends
My only problem now is that I can't figure out how to implement the
following:
A Discovery (a mapped class) needs to have a foreign key to the source
that made the discovery, this could be either a lab or a scientist, so
normally i would have a field with a reference to the super-class of
both Scientist and Lab - However, I don't have a super-class, I just
have a trait :)
I would like to be able to write something like this:
/--- code starts again
class Discovery extends LongKeyedMapper[Discovery] with IdPK {
def getSingleton = Discovery
// primatives
object description extends MappedDateTime(this)
object year extends MappedInt(this)
object reference extends MappedPoliteString(this, 128)
// relationships
object source extends MappedLongForeignKey(this, BaseSourceTrait)
//
-- this is what i want.
}
object Discovery extends Discovery with LongKeyedMetaMapper[Discovery]
/--- code ends
As always I truely appreciate the help you guys are giving me :)
Thanks,
Mads Hartmann Jensen
On Feb 4, 9:56 pm, David Pollak feeder.of.the.be...@gmail.com wrote:
Please take a look at the MegaProtoUser and MegaMetaProtoUser code for
examples of how to create traits that can be mixed into classes.
Does that help?
On Thu, Feb 4, 2010 at 9:58 AM, Mads Hartmann Jensen
mads...@gmail.comwrote:
hello Jeppe,
In my project I've got the following three models: A discovery, a
Scientist
and a lab. The Discovery has been invented by someone, this is either a
single scientist or sometimes a lab - This is easily done through
inheritance (would create a superclass named source) but I'm not sure
how to
do this so it maps nicely to the database.
Scientist and Lab only share one attribute so what I'm most interested in
is to be able express that a Discovery has s source that can be either a
lab
or scientist :)
Hope this explains my problem more clearly, thanks for the help
Mads Hartmann
Sent from my iPhone
On 04/02/2010, at 18.17, Jeppe Nejsum Madsen je...@ingolfs.dk wrote:
Mads Hartmann mads...@gmail.com writes:
Hello Everyone,
I'm currently trying to figure out how to map objects with inheritance
using the Mapper framework. I've got a Lab and a Scientist who inherit
from Source.
As I understand there's no direct way to do inheritance using the
Mapper framework so I'm trying to figure out how to implement 'Single
Table Inheritance'.
Right now I'm trying to create a single trait (Source) for the values
that they share called BaseSource and my idea is to mix it
Re: [Lift] Re: Single Table Inheritance
Basically, either use two protected LongMappedMappers and a public
getter/setter that takes a boolean into account in both directions; or use a
MappedLong, with
def obj = whicheverLookUpTable.find(this.is)
and
override def set(s: Source) = s match ...
Sorry for the brevity, if unclear please ask.
-
Mads Hartmannmads...@gmail.com wrote:
Naftoli would you please re-post your solution :) I could really use
the help
On Feb 5, 6:56 pm, Naftoli Gugenheim naftoli...@gmail.com wrote:
Peek --www.getpeek.com
Please forward any bad messages to feedb...@getpeek.com
-
Ross Mellgrendri...@gmail.com wrote:
This is actually fairly common that messages Naftoli sends are empty, or
don't get threaded onto the original discussion, or formatting comes out
funny. Naftoli, what email client are you using?
-Ross
On Feb 5, 2010, at 1:49 AM, Mads Hartmann wrote:
Hey Naftoli,
I think something might have broken your first message, It's a blank
message if you view it through the web-interface:
http://groups.google.com/group/liftweb/browse_thread/thread/e2317e5db...
If you have a solution I would love to hear it :)
On Feb 5, 1:52 am, Naftoli Gugenheim naftoli...@gmail.com wrote:
Does my approach not work?
-
Mads Hartmannmads...@gmail.com wrote:
Yeah that helped, my lab and scientist now looks like this:
/--- code
trait BaseSourceTrait[ T :BaseSourceTrait[T] ] extends
LongKeyedMapper[T] {
self: T =
override def primaryKeyField = id
object id extends MappedLongIndex(this)
object name extends MappedPoliteString(this, 256)
object sourceType extends MappedEnum(this,SourceTypes)
object SourceTypes extends Enumeration {
val Scientist = Value(Scientist)
val Lab = Value(Lab)
}
}
class Scientist extends BaseSourceTrait[Scientist] {
def getSingleton = Scientist
object birth extends MappedInt(this)
object death extends MappedInt(this)
object nationality extends MappedPoliteString(this, 128)
}
object Scientist extends Scientist with LongKeyedMetaMapper[Scientist]
{
override def dbTableName = Source
}
class Lab extends BaseSourceTrait[Lab] {
def getSingleton = Lab
object institution extends MappedLongForeignKey(this, Institution)
}
object Lab extends Lab with LongKeyedMetaMapper[Lab] {
override def dbTableName = Source
}
/--- code ends
My only problem now is that I can't figure out how to implement the
following:
A Discovery (a mapped class) needs to have a foreign key to the source
that made the discovery, this could be either a lab or a scientist, so
normally i would have a field with a reference to the super-class of
both Scientist and Lab - However, I don't have a super-class, I just
have a trait :)
I would like to be able to write something like this:
/--- code starts again
class Discovery extends LongKeyedMapper[Discovery] with IdPK {
def getSingleton = Discovery
// primatives
object description extends MappedDateTime(this)
object year extends MappedInt(this)
object reference extends MappedPoliteString(this, 128)
// relationships
object source extends MappedLongForeignKey(this, BaseSourceTrait)
//
-- this is what i want.
}
object Discovery extends Discovery with LongKeyedMetaMapper[Discovery]
/--- code ends
As always I truely appreciate the help you guys are giving me :)
Thanks,
Mads Hartmann Jensen
On Feb 4, 9:56 pm, David Pollak feeder.of.the.be...@gmail.com wrote:
Please take a look at the MegaProtoUser and MegaMetaProtoUser code for
examples of how to create traits that can be mixed into classes.
Does that help?
On Thu, Feb 4, 2010 at 9:58 AM, Mads Hartmann Jensen
mads...@gmail.comwrote:
hello Jeppe,
In my project I've got the following three models: A discovery, a
Scientist
and a lab. The Discovery has been invented by someone, this is either a
single scientist or sometimes a lab - This is easily done through
inheritance (would create a superclass named source) but I'm not sure
how to
do this so it maps nicely to the database.
Scientist and Lab only share one attribute so what I'm most interested in
is to be able express that a Discovery has s source that can be either a
lab
or scientist :)
Hope this explains my problem more clearly, thanks for the help
Mads Hartmann
Sent from my iPhone
On 04/02/2010, at 18.17, Jeppe Nejsum Madsen je...@ingolfs.dk wrote:
Mads Hartmann mads...@gmail.com writes:
Hello Everyone,
I'm currently trying to figure out how to map objects with inheritance
using
[Lift] Re: Single Table Inheritance
Thank you for taking your time to answer my question
I don't think I fully understand how to implement any of the suggested
solutions, if you have the time I would love a code example :)
Thanks a lot,
Mads Hartmann Jensen
On Feb 5, 7:34 pm, Naftoli Gugenheim naftoli...@gmail.com wrote:
Basically, either use two protected LongMappedMappers and a public
getter/setter that takes a boolean into account in both directions; or use a
MappedLong, with
def obj = whicheverLookUpTable.find(this.is)
and
override def set(s: Source) = s match ...
Sorry for the brevity, if unclear please ask.
-
Mads Hartmannmads...@gmail.com wrote:
Naftoli would you please re-post your solution :) I could really use
the help
On Feb 5, 6:56 pm, Naftoli Gugenheim naftoli...@gmail.com wrote:
Peek --www.getpeek.com
Please forward any bad messages to feedb...@getpeek.com
-
Ross Mellgrendri...@gmail.com wrote:
This is actually fairly common that messages Naftoli sends are empty, or
don't get threaded onto the original discussion, or formatting comes out
funny. Naftoli, what email client are you using?
-Ross
On Feb 5, 2010, at 1:49 AM, Mads Hartmann wrote:
Hey Naftoli,
I think something might have broken your first message, It's a blank
message if you view it through the web-interface:
http://groups.google.com/group/liftweb/browse_thread/thread/e2317e5db...
If you have a solution I would love to hear it :)
On Feb 5, 1:52 am, Naftoli Gugenheim naftoli...@gmail.com wrote:
Does my approach not work?
-
Mads Hartmannmads...@gmail.com wrote:
Yeah that helped, my lab and scientist now looks like this:
/--- code
trait BaseSourceTrait[ T :BaseSourceTrait[T] ] extends
LongKeyedMapper[T] {
self: T =
override def primaryKeyField = id
object id extends MappedLongIndex(this)
object name extends MappedPoliteString(this, 256)
object sourceType extends MappedEnum(this,SourceTypes)
object SourceTypes extends Enumeration {
val Scientist = Value(Scientist)
val Lab = Value(Lab)
}
}
class Scientist extends BaseSourceTrait[Scientist] {
def getSingleton = Scientist
object birth extends MappedInt(this)
object death extends MappedInt(this)
object nationality extends MappedPoliteString(this, 128)
}
object Scientist extends Scientist with LongKeyedMetaMapper[Scientist]
{
override def dbTableName = Source
}
class Lab extends BaseSourceTrait[Lab] {
def getSingleton = Lab
object institution extends MappedLongForeignKey(this, Institution)
}
object Lab extends Lab with LongKeyedMetaMapper[Lab] {
override def dbTableName = Source
}
/--- code ends
My only problem now is that I can't figure out how to implement the
following:
A Discovery (a mapped class) needs to have a foreign key to the source
that made the discovery, this could be either a lab or a scientist, so
normally i would have a field with a reference to the super-class of
both Scientist and Lab - However, I don't have a super-class, I just
have a trait :)
I would like to be able to write something like this:
/--- code starts again
class Discovery extends LongKeyedMapper[Discovery] with IdPK {
def getSingleton = Discovery
// primatives
object description extends MappedDateTime(this)
object year extends MappedInt(this)
object reference extends MappedPoliteString(this, 128)
// relationships
object source extends MappedLongForeignKey(this,
BaseSourceTrait) //
-- this is what i want.
}
object Discovery extends Discovery with LongKeyedMetaMapper[Discovery]
/--- code ends
As always I truely appreciate the help you guys are giving me :)
Thanks,
Mads Hartmann Jensen
On Feb 4, 9:56 pm, David Pollak feeder.of.the.be...@gmail.com wrote:
Please take a look at the MegaProtoUser and MegaMetaProtoUser code for
examples of how to create traits that can be mixed into classes.
Does that help?
On Thu, Feb 4, 2010 at 9:58 AM, Mads Hartmann Jensen
mads...@gmail.comwrote:
hello Jeppe,
In my project I've got the following three models: A discovery, a
Scientist
and a lab. The Discovery has been invented by someone, this is either a
single scientist or sometimes a lab - This is easily done through
inheritance (would create a superclass named source) but I'm not sure
how to
do this so it maps nicely to the database.
Scientist and Lab only share one attribute so what I'm most interested
in
is to be able express
Re: [Lift] Re: Single Table Inheritance
Not tested or compiled
object isLab extends MappedBoolean(this)
1.
def source: Box[Source] = if(isLab.is) lab.obj else scientist.obj
def source_=(s: Source) = s match {
case l: Lab = isLab(true); lab(l)
// same for scientist
}
2.
object source extends MappedLong {
def obj = if(isLab) Lab.find(is) else Scientist.find(is)
def obj_=(s: Source) = s match {
case _: Lab = set(s.id)
// same for scientist
}
The advantage of 1 is database FK constraints.
The advantage of 2 is fewer fields.
-
Mads Hartmannmads...@gmail.com wrote:
Thank you for taking your time to answer my question
I don't think I fully understand how to implement any of the suggested
solutions, if you have the time I would love a code example :)
Thanks a lot,
Mads Hartmann Jensen
On Feb 5, 7:34 pm, Naftoli Gugenheim naftoli...@gmail.com wrote:
Basically, either use two protected LongMappedMappers and a public
getter/setter that takes a boolean into account in both directions; or use a
MappedLong, with
def obj = whicheverLookUpTable.find(this.is)
and
override def set(s: Source) = s match ...
Sorry for the brevity, if unclear please ask.
-
Mads Hartmannmads...@gmail.com wrote:
Naftoli would you please re-post your solution :) I could really use
the help
On Feb 5, 6:56 pm, Naftoli Gugenheim naftoli...@gmail.com wrote:
Peek --www.getpeek.com
Please forward any bad messages to feedb...@getpeek.com
-
Ross Mellgrendri...@gmail.com wrote:
This is actually fairly common that messages Naftoli sends are empty, or
don't get threaded onto the original discussion, or formatting comes out
funny. Naftoli, what email client are you using?
-Ross
On Feb 5, 2010, at 1:49 AM, Mads Hartmann wrote:
Hey Naftoli,
I think something might have broken your first message, It's a blank
message if you view it through the web-interface:
http://groups.google.com/group/liftweb/browse_thread/thread/e2317e5db...
If you have a solution I would love to hear it :)
On Feb 5, 1:52 am, Naftoli Gugenheim naftoli...@gmail.com wrote:
Does my approach not work?
-
Mads Hartmannmads...@gmail.com wrote:
Yeah that helped, my lab and scientist now looks like this:
/--- code
trait BaseSourceTrait[ T :BaseSourceTrait[T] ] extends
LongKeyedMapper[T] {
self: T =
override def primaryKeyField = id
object id extends MappedLongIndex(this)
object name extends MappedPoliteString(this, 256)
object sourceType extends MappedEnum(this,SourceTypes)
object SourceTypes extends Enumeration {
val Scientist = Value(Scientist)
val Lab = Value(Lab)
}
}
class Scientist extends BaseSourceTrait[Scientist] {
def getSingleton = Scientist
object birth extends MappedInt(this)
object death extends MappedInt(this)
object nationality extends MappedPoliteString(this, 128)
}
object Scientist extends Scientist with LongKeyedMetaMapper[Scientist]
{
override def dbTableName = Source
}
class Lab extends BaseSourceTrait[Lab] {
def getSingleton = Lab
object institution extends MappedLongForeignKey(this, Institution)
}
object Lab extends Lab with LongKeyedMetaMapper[Lab] {
override def dbTableName = Source
}
/--- code ends
My only problem now is that I can't figure out how to implement the
following:
A Discovery (a mapped class) needs to have a foreign key to the source
that made the discovery, this could be either a lab or a scientist, so
normally i would have a field with a reference to the super-class of
both Scientist and Lab - However, I don't have a super-class, I just
have a trait :)
I would like to be able to write something like this:
/--- code starts again
class Discovery extends LongKeyedMapper[Discovery] with IdPK {
def getSingleton = Discovery
// primatives
object description extends MappedDateTime(this)
object year extends MappedInt(this)
object reference extends MappedPoliteString(this, 128)
// relationships
object source extends MappedLongForeignKey(this,
BaseSourceTrait) //
-- this is what i want.
}
object Discovery extends Discovery with LongKeyedMetaMapper[Discovery]
/--- code ends
As always I truely appreciate the help you guys are giving me :)
Thanks,
Mads Hartmann Jensen
On Feb 4, 9:56 pm, David Pollak feeder.of.the.be...@gmail.com wrote:
Please take a look at the MegaProtoUser and MegaMetaProtoUser code for
examples of how to create traits that can be mixed into classes.
[Lift] Re: Single Table Inheritance
Ah! It seems to be working now - Thanks a lot :)
On Feb 5, 8:15 pm, Naftoli Gugenheim naftoli...@gmail.com wrote:
Not tested or compiled
object isLab extends MappedBoolean(this)
1.
def source: Box[Source] = if(isLab.is) lab.obj else scientist.obj
def source_=(s: Source) = s match {
case l: Lab = isLab(true); lab(l)
// same for scientist
}
2.
object source extends MappedLong {
def obj = if(isLab) Lab.find(is) else Scientist.find(is)
def obj_=(s: Source) = s match {
case _: Lab = set(s.id)
// same for scientist
}
The advantage of 1 is database FK constraints.
The advantage of 2 is fewer fields.
-
Mads Hartmannmads...@gmail.com wrote:
Thank you for taking your time to answer my question
I don't think I fully understand how to implement any of the suggested
solutions, if you have the time I would love a code example :)
Thanks a lot,
Mads Hartmann Jensen
On Feb 5, 7:34 pm, Naftoli Gugenheim naftoli...@gmail.com wrote:
Basically, either use two protected LongMappedMappers and a public
getter/setter that takes a boolean into account in both directions; or use
a MappedLong, with
def obj = whicheverLookUpTable.find(this.is)
and
override def set(s: Source) = s match ...
Sorry for the brevity, if unclear please ask.
-
Mads Hartmannmads...@gmail.com wrote:
Naftoli would you please re-post your solution :) I could really use
the help
On Feb 5, 6:56 pm, Naftoli Gugenheim naftoli...@gmail.com wrote:
Peek --www.getpeek.com
Please forward any bad messages to feedb...@getpeek.com
-
Ross Mellgrendri...@gmail.com wrote:
This is actually fairly common that messages Naftoli sends are empty, or
don't get threaded onto the original discussion, or formatting comes out
funny. Naftoli, what email client are you using?
-Ross
On Feb 5, 2010, at 1:49 AM, Mads Hartmann wrote:
Hey Naftoli,
I think something might have broken your first message, It's a blank
message if you view it through the web-interface:
http://groups.google.com/group/liftweb/browse_thread/thread/e2317e5db...
If you have a solution I would love to hear it :)
On Feb 5, 1:52 am, Naftoli Gugenheim naftoli...@gmail.com wrote:
Does my approach not work?
-
Mads Hartmannmads...@gmail.com wrote:
Yeah that helped, my lab and scientist now looks like this:
/--- code
trait BaseSourceTrait[ T :BaseSourceTrait[T] ] extends
LongKeyedMapper[T] {
self: T =
override def primaryKeyField = id
object id extends MappedLongIndex(this)
object name extends MappedPoliteString(this, 256)
object sourceType extends MappedEnum(this,SourceTypes)
object SourceTypes extends Enumeration {
val Scientist = Value(Scientist)
val Lab = Value(Lab)
}
}
class Scientist extends BaseSourceTrait[Scientist] {
def getSingleton = Scientist
object birth extends MappedInt(this)
object death extends MappedInt(this)
object nationality extends MappedPoliteString(this, 128)
}
object Scientist extends Scientist with LongKeyedMetaMapper[Scientist]
{
override def dbTableName = Source
}
class Lab extends BaseSourceTrait[Lab] {
def getSingleton = Lab
object institution extends MappedLongForeignKey(this, Institution)
}
object Lab extends Lab with LongKeyedMetaMapper[Lab] {
override def dbTableName = Source
}
/--- code ends
My only problem now is that I can't figure out how to implement the
following:
A Discovery (a mapped class) needs to have a foreign key to the source
that made the discovery, this could be either a lab or a scientist, so
normally i would have a field with a reference to the super-class of
both Scientist and Lab - However, I don't have a super-class, I just
have a trait :)
I would like to be able to write something like this:
/--- code starts again
class Discovery extends LongKeyedMapper[Discovery] with IdPK {
def getSingleton = Discovery
// primatives
object description extends MappedDateTime(this)
object year extends MappedInt(this)
object reference extends MappedPoliteString(this, 128)
// relationships
object source extends MappedLongForeignKey(this,
BaseSourceTrait) //
-- this is what i want.
}
object Discovery extends Discovery with LongKeyedMetaMapper[Discovery]
/--- code ends
As always I truely appreciate the help you guys are giving me :)
Thanks,
Mads
[Lift] Re: Single Table Inheritance
Yeah that helped, my lab and scientist now looks like this:
/--- code
trait BaseSourceTrait[ T :BaseSourceTrait[T] ] extends
LongKeyedMapper[T] {
self: T =
override def primaryKeyField = id
object id extends MappedLongIndex(this)
object name extends MappedPoliteString(this, 256)
object sourceType extends MappedEnum(this,SourceTypes)
object SourceTypes extends Enumeration {
val Scientist = Value(Scientist)
val Lab = Value(Lab)
}
}
class Scientist extends BaseSourceTrait[Scientist] {
def getSingleton = Scientist
object birth extends MappedInt(this)
object death extends MappedInt(this)
object nationality extends MappedPoliteString(this, 128)
}
object Scientist extends Scientist with LongKeyedMetaMapper[Scientist]
{
override def dbTableName = Source
}
class Lab extends BaseSourceTrait[Lab] {
def getSingleton = Lab
object institution extends MappedLongForeignKey(this, Institution)
}
object Lab extends Lab with LongKeyedMetaMapper[Lab] {
override def dbTableName = Source
}
/--- code ends
My only problem now is that I can't figure out how to implement the
following:
A Discovery (a mapped class) needs to have a foreign key to the source
that made the discovery, this could be either a lab or a scientist, so
normally i would have a field with a reference to the super-class of
both Scientist and Lab - However, I don't have a super-class, I just
have a trait :)
I would like to be able to write something like this:
/--- code starts again
class Discovery extends LongKeyedMapper[Discovery] with IdPK {
def getSingleton = Discovery
// primatives
object description extends MappedDateTime(this)
object year extends MappedInt(this)
object reference extends MappedPoliteString(this, 128)
// relationships
object source extends MappedLongForeignKey(this, BaseSourceTrait) //
-- this is what i want.
}
object Discovery extends Discovery with LongKeyedMetaMapper[Discovery]
/--- code ends
As always I truely appreciate the help you guys are giving me :)
Thanks,
Mads Hartmann Jensen
On Feb 4, 9:56 pm, David Pollak feeder.of.the.be...@gmail.com wrote:
Please take a look at the MegaProtoUser and MegaMetaProtoUser code for
examples of how to create traits that can be mixed into classes.
Does that help?
On Thu, Feb 4, 2010 at 9:58 AM, Mads Hartmann Jensen mads...@gmail.comwrote:
hello Jeppe,
In my project I've got the following three models: A discovery, a Scientist
and a lab. The Discovery has been invented by someone, this is either a
single scientist or sometimes a lab - This is easily done through
inheritance (would create a superclass named source) but I'm not sure how to
do this so it maps nicely to the database.
Scientist and Lab only share one attribute so what I'm most interested in
is to be able express that a Discovery has s source that can be either a lab
or scientist :)
Hope this explains my problem more clearly, thanks for the help
Mads Hartmann
Sent from my iPhone
On 04/02/2010, at 18.17, Jeppe Nejsum Madsen je...@ingolfs.dk wrote:
Mads Hartmann mads...@gmail.com writes:
Hello Everyone,
I'm currently trying to figure out how to map objects with inheritance
using the Mapper framework. I've got a Lab and a Scientist who inherit
from Source.
As I understand there's no direct way to do inheritance using the
Mapper framework so I'm trying to figure out how to implement 'Single
Table Inheritance'.
Right now I'm trying to create a single trait (Source) for the values
that they share called BaseSource and my idea is to mix it in both Lab
and Scientist. I would then define the table name of both scientist
and lab to be the same - I think this would work but what I'm not sure
of is the following:
- If both Scientist and Lab mixes in the IdPK trait and use the same
table, will the id still be unique?
- A Discovery has a source, how do i create MappedLongForeignKey to
the table they share (lab, scientist)?
I hope you'll be able to help me out :)
I can't say I follow the above :-) Do you want to share tables, code or
both? Maybe list the table structure and explain how you would like to
map it
/Jeppe
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To post to this group, send email to
Re: [Lift] Re: Single Table Inheritance
Does my approach not work?
-
Mads Hartmannmads...@gmail.com wrote:
Yeah that helped, my lab and scientist now looks like this:
/--- code
trait BaseSourceTrait[ T :BaseSourceTrait[T] ] extends
LongKeyedMapper[T] {
self: T =
override def primaryKeyField = id
object id extends MappedLongIndex(this)
object name extends MappedPoliteString(this, 256)
object sourceType extends MappedEnum(this,SourceTypes)
object SourceTypes extends Enumeration {
val Scientist = Value(Scientist)
val Lab = Value(Lab)
}
}
class Scientist extends BaseSourceTrait[Scientist] {
def getSingleton = Scientist
object birth extends MappedInt(this)
object death extends MappedInt(this)
object nationality extends MappedPoliteString(this, 128)
}
object Scientist extends Scientist with LongKeyedMetaMapper[Scientist]
{
override def dbTableName = Source
}
class Lab extends BaseSourceTrait[Lab] {
def getSingleton = Lab
object institution extends MappedLongForeignKey(this, Institution)
}
object Lab extends Lab with LongKeyedMetaMapper[Lab] {
override def dbTableName = Source
}
/--- code ends
My only problem now is that I can't figure out how to implement the
following:
A Discovery (a mapped class) needs to have a foreign key to the source
that made the discovery, this could be either a lab or a scientist, so
normally i would have a field with a reference to the super-class of
both Scientist and Lab - However, I don't have a super-class, I just
have a trait :)
I would like to be able to write something like this:
/--- code starts again
class Discovery extends LongKeyedMapper[Discovery] with IdPK {
def getSingleton = Discovery
// primatives
object description extends MappedDateTime(this)
object year extends MappedInt(this)
object reference extends MappedPoliteString(this, 128)
// relationships
object source extends MappedLongForeignKey(this, BaseSourceTrait) //
-- this is what i want.
}
object Discovery extends Discovery with LongKeyedMetaMapper[Discovery]
/--- code ends
As always I truely appreciate the help you guys are giving me :)
Thanks,
Mads Hartmann Jensen
On Feb 4, 9:56 pm, David Pollak feeder.of.the.be...@gmail.com wrote:
Please take a look at the MegaProtoUser and MegaMetaProtoUser code for
examples of how to create traits that can be mixed into classes.
Does that help?
On Thu, Feb 4, 2010 at 9:58 AM, Mads Hartmann Jensen mads...@gmail.comwrote:
hello Jeppe,
In my project I've got the following three models: A discovery, a Scientist
and a lab. The Discovery has been invented by someone, this is either a
single scientist or sometimes a lab - This is easily done through
inheritance (would create a superclass named source) but I'm not sure how to
do this so it maps nicely to the database.
Scientist and Lab only share one attribute so what I'm most interested in
is to be able express that a Discovery has s source that can be either a lab
or scientist :)
Hope this explains my problem more clearly, thanks for the help
Mads Hartmann
Sent from my iPhone
On 04/02/2010, at 18.17, Jeppe Nejsum Madsen je...@ingolfs.dk wrote:
Mads Hartmann mads...@gmail.com writes:
Hello Everyone,
I'm currently trying to figure out how to map objects with inheritance
using the Mapper framework. I've got a Lab and a Scientist who inherit
from Source.
As I understand there's no direct way to do inheritance using the
Mapper framework so I'm trying to figure out how to implement 'Single
Table Inheritance'.
Right now I'm trying to create a single trait (Source) for the values
that they share called BaseSource and my idea is to mix it in both Lab
and Scientist. I would then define the table name of both scientist
and lab to be the same - I think this would work but what I'm not sure
of is the following:
- If both Scientist and Lab mixes in the IdPK trait and use the same
table, will the id still be unique?
- A Discovery has a source, how do i create MappedLongForeignKey to
the table they share (lab, scientist)?
I hope you'll be able to help me out :)
I can't say I follow the above :-) Do you want to share tables, code or
both? Maybe list the table structure and explain how you would like to
map it
/Jeppe
--
You received this message because you are subscribed to the Google Groups
Lift group.
To post to this group, send email to lift...@googlegroups.com.
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You received this message because you are
[Lift] Re: Single Table Inheritance
Hey Naftoli,
I think something might have broken your first message, It's a blank
message if you view it through the web-interface:
http://groups.google.com/group/liftweb/browse_thread/thread/e2317e5dbaad4a65
If you have a solution I would love to hear it :)
On Feb 5, 1:52 am, Naftoli Gugenheim naftoli...@gmail.com wrote:
Does my approach not work?
-
Mads Hartmannmads...@gmail.com wrote:
Yeah that helped, my lab and scientist now looks like this:
/--- code
trait BaseSourceTrait[ T :BaseSourceTrait[T] ] extends
LongKeyedMapper[T] {
self: T =
override def primaryKeyField = id
object id extends MappedLongIndex(this)
object name extends MappedPoliteString(this, 256)
object sourceType extends MappedEnum(this,SourceTypes)
object SourceTypes extends Enumeration {
val Scientist = Value(Scientist)
val Lab = Value(Lab)
}
}
class Scientist extends BaseSourceTrait[Scientist] {
def getSingleton = Scientist
object birth extends MappedInt(this)
object death extends MappedInt(this)
object nationality extends MappedPoliteString(this, 128)
}
object Scientist extends Scientist with LongKeyedMetaMapper[Scientist]
{
override def dbTableName = Source
}
class Lab extends BaseSourceTrait[Lab] {
def getSingleton = Lab
object institution extends MappedLongForeignKey(this, Institution)
}
object Lab extends Lab with LongKeyedMetaMapper[Lab] {
override def dbTableName = Source
}
/--- code ends
My only problem now is that I can't figure out how to implement the
following:
A Discovery (a mapped class) needs to have a foreign key to the source
that made the discovery, this could be either a lab or a scientist, so
normally i would have a field with a reference to the super-class of
both Scientist and Lab - However, I don't have a super-class, I just
have a trait :)
I would like to be able to write something like this:
/--- code starts again
class Discovery extends LongKeyedMapper[Discovery] with IdPK {
def getSingleton = Discovery
// primatives
object description extends MappedDateTime(this)
object year extends MappedInt(this)
object reference extends MappedPoliteString(this, 128)
// relationships
object source extends MappedLongForeignKey(this, BaseSourceTrait) //
-- this is what i want.
}
object Discovery extends Discovery with LongKeyedMetaMapper[Discovery]
/--- code ends
As always I truely appreciate the help you guys are giving me :)
Thanks,
Mads Hartmann Jensen
On Feb 4, 9:56 pm, David Pollak feeder.of.the.be...@gmail.com wrote:
Please take a look at the MegaProtoUser and MegaMetaProtoUser code for
examples of how to create traits that can be mixed into classes.
Does that help?
On Thu, Feb 4, 2010 at 9:58 AM, Mads Hartmann Jensen
mads...@gmail.comwrote:
hello Jeppe,
In my project I've got the following three models: A discovery, a
Scientist
and a lab. The Discovery has been invented by someone, this is either a
single scientist or sometimes a lab - This is easily done through
inheritance (would create a superclass named source) but I'm not sure how
to
do this so it maps nicely to the database.
Scientist and Lab only share one attribute so what I'm most interested in
is to be able express that a Discovery has s source that can be either a
lab
or scientist :)
Hope this explains my problem more clearly, thanks for the help
Mads Hartmann
Sent from my iPhone
On 04/02/2010, at 18.17, Jeppe Nejsum Madsen je...@ingolfs.dk wrote:
Mads Hartmann mads...@gmail.com writes:
Hello Everyone,
I'm currently trying to figure out how to map objects with inheritance
using the Mapper framework. I've got a Lab and a Scientist who inherit
from Source.
As I understand there's no direct way to do inheritance using the
Mapper framework so I'm trying to figure out how to implement 'Single
Table Inheritance'.
Right now I'm trying to create a single trait (Source) for the values
that they share called BaseSource and my idea is to mix it in both Lab
and Scientist. I would then define the table name of both scientist
and lab to be the same - I think this would work but what I'm not sure
of is the following:
- If both Scientist and Lab mixes in the IdPK trait and use the same
table, will the id still be unique?
- A Discovery has a source, how do i create MappedLongForeignKey to
the table they share (lab, scientist)?
I hope you'll be able to help me out :)
I can't say I follow the above :-) Do you want to share tables, code or
both? Maybe list the table structure and explain how you would like to
map
