list – ぷすぅ～ぷすぅ～

以下のようなエラー


instantiating bean of type [org.grails.orm.hibernate.HibernateDatastore]: Duplicate property mapping of _booksIndexBackref found in domain.Book
io.micronaut.context.exceptions.BeanInstantiationException: Bean definition [org.grails.orm.hibernate.HibernateDatastore] could not be loaded: Error instantiating bean of type [org.grails.orm.hibernate.HibernateDatastore]: Duplicate property mapping of _booksIndexBackref found in domain.Book
        at io.micronaut.context.DefaultBeanContext.initializeContext(DefaultBeanContext.java:1549)
        at io.micronaut.context.DefaultApplicationContext.initializeContext(DefaultApplicationContext.java:220)
        at io.micronaut.context.DefaultBeanContext.readAllBeanDefinitionClasses(DefaultBeanContext.java:2812)
        at io.micronaut.context.DefaultBeanContext.start(DefaultBeanContext.java:233)
        at io.micronaut.context.DefaultApplicationContext.start(DefaultApplicationContext.java:166)
        at io.micronaut.runtime.Micronaut.start(Micronaut.java:71)

Caused by: io.micronaut.context.exceptions.BeanInstantiationException: Error instantiating bean of type [org.grails.orm.hibernate.HibernateDatastore]: Duplicate property mapping of _booksIndexBackref found in domain.Book
        at io.micronaut.context.DefaultBeanContext.doCreateBean(DefaultBeanContext.java:1927)
        at io.micronaut.context.DefaultBeanContext.createAndRegisterSingletonInternal(DefaultBeanContext.java:2679)
        at io.micronaut.context.DefaultBeanContext.loadContextScopeBean(DefaultBeanContext.java:2215)
        at io.micronaut.context.DefaultBeanContext.initializeContext(DefaultBeanContext.java:1543)
        ... 6 common frames omitted
Caused by: org.hibernate.MappingException: Duplicate property mapping of _booksIndexBackref found in domain.Book
        at org.hibernate.mapping.PersistentClass.checkPropertyDuplication(PersistentClass.java:643)
        at org.hibernate.mapping.PersistentClass.validate(PersistentClass.java:633)
        at org.hibernate.mapping.RootClass.validate(RootClass.java:267)
        at org.hibernate.boot.internal.MetadataImpl.validate(MetadataImpl.java:354)
        at org.hibernate.boot.internal.SessionFactoryBuilderImpl.build(SessionFactoryBuilderImpl.java:465)
        at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:708)
        at org.grails.orm.hibernate.cfg.HibernateMappingContextConfiguration.buildSessionFactory(HibernateMappingContextConfiguration.java:287)
        at org.grails.orm.hibernate.connections.HibernateConnectionSourceFactory.create(HibernateConnectionSourceFactory.java:86)
        at org.grails.orm.hibernate.connections.AbstractHibernateConnectionSourceFactory.create(AbstractHibernateConnectionSourceFactory.java:39)
        at org.grails.orm.hibernate.connections.AbstractHibernateConnectionSourceFactory.create(AbstractHibernateConnectionSourceFactory.java:23)
        at org.grails.datastore.mapping.core.connections.AbstractConnectionSourceFactory.create(AbstractConnectionSourceFactory.java:64)
        at org.grails.datastore.mapping.core.connections.AbstractConnectionSourceFactory.create(AbstractConnectionSourceFactory.java:52)
        at org.grails.datastore.mapping.core.connections.ConnectionSourcesInitializer.create(ConnectionSourcesInitializer.groovy:24)
        at org.grails.orm.hibernate.HibernateDatastore.<init>(HibernateDatastore.java:212)
        at org.grails.orm.hibernate.HibernateDatastore.<init>(HibernateDatastore.java:233)
        at io.micronaut.configuration.hibernate.gorm.HibernateDatastoreFactory.hibernateDatastore(HibernateDatastoreFactory.groovy:63)
        at io.micronaut.configuration.hibernate.gorm.$HibernateDatastoreFactory$HibernateDatastore0Definition.build(Unknown Source)
        at io.micronaut.context.DefaultBeanContext.doCreateBean(DefaultBeanContext.java:1898)
        ... 9 common frames omitted

instantiating bean of type [org.grails.orm.hibernate.HibernateDatastore]: Duplicate property mapping of _booksIndexBackref found in domain.Book

io.micronaut.context.exceptions.BeanInstantiationException: Bean definition [org.grails.orm.hibernate.HibernateDatastore] could not be loaded: Error instantiating bean of type [org.grails.orm.hibernate.HibernateDatastore]: Duplicate property mapping of _booksIndexBackref found in domain.Book

at io.micronaut.context.DefaultBeanContext.initializeContext(DefaultBeanContext.java:1549)

at io.micronaut.context.DefaultApplicationContext.initializeContext(DefaultApplicationContext.java:220)

at io.micronaut.context.DefaultBeanContext.readAllBeanDefinitionClasses(DefaultBeanContext.java:2812)

at io.micronaut.context.DefaultBeanContext.start(DefaultBeanContext.java:233)

at io.micronaut.context.DefaultApplicationContext.start(DefaultApplicationContext.java:166)

at io.micronaut.runtime.Micronaut.start(Micronaut.java:71)

Caused by: io.micronaut.context.exceptions.BeanInstantiationException: Error instantiating bean of type [org.grails.orm.hibernate.HibernateDatastore]: Duplicate property mapping of _booksIndexBackref found in domain.Book

at io.micronaut.context.DefaultBeanContext.doCreateBean(DefaultBeanContext.java:1927)

at io.micronaut.context.DefaultBeanContext.createAndRegisterSingletonInternal(DefaultBeanContext.java:2679)

at io.micronaut.context.DefaultBeanContext.loadContextScopeBean(DefaultBeanContext.java:2215)

at io.micronaut.context.DefaultBeanContext.initializeContext(DefaultBeanContext.java:1543)

... 6 common frames omitted

Caused by: org.hibernate.MappingException: Duplicate property mapping of _booksIndexBackref found in domain.Book

at org.hibernate.mapping.PersistentClass.checkPropertyDuplication(PersistentClass.java:643)

at org.hibernate.mapping.PersistentClass.validate(PersistentClass.java:633)

at org.hibernate.mapping.RootClass.validate(RootClass.java:267)

at org.hibernate.boot.internal.MetadataImpl.validate(MetadataImpl.java:354)

at org.hibernate.boot.internal.SessionFactoryBuilderImpl.build(SessionFactoryBuilderImpl.java:465)

at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:708)

at org.grails.orm.hibernate.cfg.HibernateMappingContextConfiguration.buildSessionFactory(HibernateMappingContextConfiguration.java:287)

at org.grails.orm.hibernate.connections.HibernateConnectionSourceFactory.create(HibernateConnectionSourceFactory.java:86)

at org.grails.orm.hibernate.connections.AbstractHibernateConnectionSourceFactory.create(AbstractHibernateConnectionSourceFactory.java:39)

at org.grails.orm.hibernate.connections.AbstractHibernateConnectionSourceFactory.create(AbstractHibernateConnectionSourceFactory.java:23)

at org.grails.datastore.mapping.core.connections.AbstractConnectionSourceFactory.create(AbstractConnectionSourceFactory.java:64)

at org.grails.datastore.mapping.core.connections.AbstractConnectionSourceFactory.create(AbstractConnectionSourceFactory.java:52)

at org.grails.datastore.mapping.core.connections.ConnectionSourcesInitializer.create(ConnectionSourcesInitializer.groovy:24)

at org.grails.orm.hibernate.HibernateDatastore.<init>(HibernateDatastore.java:212)

at org.grails.orm.hibernate.HibernateDatastore.<init>(HibernateDatastore.java:233)

at io.micronaut.configuration.hibernate.gorm.HibernateDatastoreFactory.hibernateDatastore(HibernateDatastoreFactory.groovy:63)

at io.micronaut.configuration.hibernate.gorm.$HibernateDatastoreFactory$HibernateDatastore0Definition.build(Unknown Source)

at io.micronaut.context.DefaultBeanContext.doCreateBean(DefaultBeanContext.java:1898)

... 9 common frames omitted

原因は、hasMany で持ってる子のデータの順序を担保するために、Listで保持していたがその時の名前が被っていたため。


class Book {
	
}

class Author {
    List books = []
    static hasMany =[books: Book]
}


class BookStore  {
    List books = []
    static hasMany =[books: Book]	
}

class Book {

}

class Author {

List books = []

static hasMany =[books: Book]

}

class BookStore {

List books = []

static hasMany =[books: Book]

}

このようにすると、 Book テーブルに、 books_idx というカラムを複数作ろうしてエラーになる。


class Book {
	
}

class Author {
    List books = []
    static hasMany =[books: Book]
}


class BookStore  {
    List bookList = []
    static hasMany =[bookList: Book]	
}

class Book {

}

class Author {

List books = []

static hasMany =[books: Book]

}

class BookStore {

List bookList = []

static hasMany =[bookList: Book]

}

このように、名前を変更すれば、
Book テーブルには、 books_idx と、 books_list_idx となるのでエラーを避けられる。

配列をランダムに取り出したいときに、インデックスの連番を配列にしてシャッフルすることがあると思います。
numpy ありなら簡単に思いつくのですが、問題は、numpy なしの場合。
あまりにも numpy に慣れてしまうと numpy なし環境で作らないといけない状況で戸惑ってしまったので記載しておきました。

例えば、IDとパスワードが入った2つの配列や、問題と正解が入った配列などです。


ids = ["ID1", "ID2", "ID3"]
pws = ["PW1", "PW2", "PW3"]

ids = ["ID1", "ID2", "ID3"]

pws = ["PW1", "PW2", "PW3"]

これをランダムに全て取りしたいときに、インデックスの配列を作ります。


list_idx = [0, 1, 2]

list_idx = [0, 1, 2]

この、list_idx をランダムにシャッフルすると、


list_idx =[2, 0, 1]

list_idx =[2, 0, 1]

そして、普通にfor文で回せばランダムに取り出せます。


for i in range(len(list_idx)) : 
    print(ids[list_idx[i]])
    print(pws[list_idx[i]])

for i in range(len(list_idx)) :

print(ids[list_idx[i]])

print(pws[list_idx[i]])

結果は


ID3
PW3
ID1
PW1
ID2
PW2

ID3

PW3

ID1

PW1

ID2

PW2

と、ランダムに全ての値が取れました。

ちょっと長くなりましたが、こんな使い方をするときにnumpyなら簡単に


import numpy as np
index_list = np.arange(10)
np.random.shuffle(index_list)

import numpy as np

index_list = np.arange(10)

np.random.shuffle(index_list)

これで、index_list は


index_list
array([0, 6, 3, 1, 8, 4, 7, 5, 2, 9])

index_list

array([0, 6, 3, 1, 8, 4, 7, 5, 2, 9])

になります。
numpy なしの場合は。

python3系


import random
index_list = list(range(0,10))
random.shuffle(index_list)

import random

index_list = list(range(0,10))

random.shuffle(index_list)

これで、index_list は


[7, 9, 1, 5, 0, 3, 6, 8, 4, 2]

[7, 9, 1, 5, 0, 3, 6, 8, 4, 2]

python2系


import random
index_list = list(xrange(0,10))
random.shuffle(index_list)

import random

index_list = list(xrange(0,10))

random.shuffle(index_list)

これで、index_list は


[5, 7, 6, 4, 0, 9, 2, 1, 3, 8]

[5, 7, 6, 4, 0, 9, 2, 1, 3, 8]

となりました。