I'm trying to pull back a list of items that have a specific type of item in a set.
For example:
<class name="Owner" table="OWNER">
<id name="id" column="OWNER_ID" />
<set name="cats" table="OWNER_CATS" lazy="false">
<key column="OWNER_ID" />
<many-to-many class="Cat" />
</set>
<class name="Cat" table="CAT" discriminator-value="C">
<id name="id" column="CAT_ID" />
<discriminator column="type" type="character" />
<subclass name="Lion" discriminator-value="L">
<property name="teeth" />
</subclass>
</class>
Using restrictions how would I get a list of owners who have lions as pets?
I've tried something along the lines of the following to no avail:
criteria.createCriteria("cats").add(Restrictions.eq("class", Lion.class));
At the moment (though I'm not sure if this is intentional) the way this works is you have to specify the discriminator value as the restriction value, rather than the class itself, so:
criteria.createCriteria("cats").add(Restrictions.eq("class", "L"));
in your example.
Related
Most all of the references to this NHibernate error (in the title) talk about child objects being deleted while still contained in a parent collection that would only re-save them later negating their "delete" (which is what the error states and the suggestion to remove object from associations that are re-saving it).
But in my case, the error happens while deleting the parent record (then the "child" is deleted via the association, so I don't want the association removed, as the error suggest)
It would have made sense if that happened every time, but I only observe this error intermittently, running exactly the same code but only against particular records. Other identical records don't trigger the condition and the delete goes through (all the time I deal with one Customer with two address-es.)
Not sure how much and what code to show. This is my "parent" object mapping:
I've got a OneCustomer-to-ManyAddresses relation mapped as a "set" of CustomerAddress "composite elements"
<class name="Customer" table="Customer">
<id name="Id" column="[Id]" type="Guid">
<generator class="guid" />
</id>
...
<set name="AddressList" lazy="true" table="CustomerAddress" cascade="all-delete-orphan" >
<key column="[CustomerId]"/>
<composite-element class="CustomerAddress">
<parent name="Customer"/>
<many-to-one name="Address"
class="Address"
column="[AddressId]"
not-null="true"
cascade="all"/>
...
</composite-element>
</set>
And this is the mapping for the "composite" object CustomerAddress:
<class name="CustomerAddress" table="CustomerAddress" >
<id name="Id" column="[Id]" type="Guid">
<generator class="guid" />
</id>
<many-to-one
name="Address"
column="[AddressId]"
class="Address"
not-null="true"
cascade="all"/>
<many-to-one
name="Customer"
column="[CustomerId]"
class="Customer"
not-null="true"
cascade="all"/>
...
</class>
What is the explanation of the error and its intermittent nature?
ADDITIONAL INFO
After further examination - looking for another collection that may hold a reference to same "Address" child, I saw the following mapping:
<class name="Address" table="Address">
<id name="Id" column="[id]" type="Guid" >
<generator class="guid" />
</id>
<!-- REMOVING THE FOLLOWING <BAG> SEEMS TO BE FIXING MY ISSUE -->
<bag name="CustomerAddressList" inverse="true" cascade="none" lazy="false" >
<key>
<column name="[AddressId]" />
</key>
<one-to-many class="CustomerAddress" />
</bag>
</class>
Removing the <bag name="CustomerAddressList"... seems to fix my issue. Explanation?
I'm going to have a guess:
You have a bi-directional association, but you haven't specified that one of them is the non-owner (by setting "inverse = true").
Try modifying the CustomerAddress relationship as follows:
<class name="CustomerAddress" table="CustomerAddress" >
<id name="Id" column="[Id]" type="Guid">
<generator class="guid" />
</id>
<many-to-one
name="Address"
column="[AddressId]"
class="Address"
not-null="true"
cascade="all"/>
<many-to-one
name="Customer"
column="[CustomerId]"
class="Customer"
not-null="true"
cascade="all"
inverse="true"
/>
...
</class>
why do you have two mappings for CustomerAddress table (one as composite Element and one as Entity)? remove the entity mapping for Customer address and it should work.
i have a an entity class which has a bag of child entity class like so(copied relevant lines):
<class name="Entity" table="Entities" lazy="false">
<id name="ID">
<generator class="guid"/>
</id>
<bag name="SubEntities" table="SubEntities" cascade="all-delete-orphan">
<key column="EntityID"/>
<one-to-many class="SubEntity"/>
</bag>
</class>
Now, the mapping works well and as expected in most cases (when i delete/save it cascades), but when i try to remove some subentity(child) from the bag in the Entity(parent) class - the change does not cascade and all i see in the DB is that the subentitiy's foreign key was changed to null, and not deleted as i would like.
I've read something about nhibernate not realizing which line it needs to delete in the database (no unique id for the row) - so i tried to use the idbag instead of the bag - but the idbag does not allow a one-to-many collection in it, i've tried something of the sort:
<idbag name="SubEntities" table="SubEntities" cascade="all-delete-orphan">
<collection-id column="Id" type="Guid">
<generator class="guid"/>
</collection-id>
<key column="EntityID"/>
<one-to-many class="SubEntity"/>
</idbag>
which of course gives the error that one-to-many isnt allowed there.
Even when i try to use the component (which i dont want as i want the child is also an entity) - i cant use an external hbm file to define it (the subentity is a rather large class by itself)
so setting the entity's propertise in the parent's hbm files isnt a good idea as well.
Could anyone help me out with explaning whats wrong and how am i supposed to fix it? i really need the subentity to be removed!
Thanks!
As requested - I"m pasting my hbm files:
For Entity:
<?xml version="1.0" encoding="utf-8" ?>
- <hibernate-mapping xmlns="urn:nhibernate-mapping-2.2" assembly="Com.Project.Shared.Common" namespace="Com.Project.Shared.Common.Entities">
- <class name="Entity" table="Entities" lazy="false">
- <id name="ID">
<generator class="guid" />
</id>
<property name="Name" />
<property name="Description" />
<property name="EndTime" />
<property name="StartTime" />
<property name="State" />
<property name="Stored" />
<property name="ClassRoomID" />
<property name="Score" />
<many-to-one name="Network" class="Network" column="NetworkID" />
- <bag name="Scenarios" cascade="all">
<key column="EntityID" />
<one-to-many class="EntScenario" />
</bag>
- <bag name="TimeLineEvents" order-by="TimeStamp" cascade="all">
<key column="EntityID" />
<one-to-many class="TimeLineEvent" />
</bag>
- <bag name="SubEntity" table="SubEntities" cascade="all-delete-orphan">
<key column="EntityID" />
<one-to-many class="SubEntity" />
</bag>
</class>
</hibernate-mapping>
for SubEntity:
<?xml version="1.0" encoding="utf-8" ?>
- <hibernate-mapping xmlns="urn:nhibernate-mapping-2.2" assembly="Com.Project.Shared.Common" namespace="Com.Project.Shared.Common.Entities">
- <class name="SubEntity" table="SubEntities" lazy="false">
- <id name="ID">
<generator class="guid" />
</id>
<many-to-one name="Name" class="EntName" column="NameID" />
<many-to-one name="Station" class="EntStation" column="StationID" />
- <bag name="Performances" table="EntPerformances" cascade="all">
<key column="SubEntityID" />
- <composite-element class="Performance">
<property name="Rank" />
<property name="Remark" />
<many-to-one name="Category" class="PerformanceCategory" column="CategoryID" index="ListIndex" />
</composite-element>
</bag>
</class>
</hibernate-mapping>
The tester i use is:
Entity newEntity = _dal.GetAll<Entity>()[0];
ObservableCollection<SubEntity> subEntities = newEntity.ObservableSubEntities;
subEntities .RemoveAt(1);
_dal.SaveItem<Entity>(newEntity);
This just turned the EntityID column in subentity into Null - but doesnt delete it.
I appericiate your help, guys.
The bag needs to have inverse="true" on it if you want it to work as expected.
This tells NHibernate that Entity is responsible to managing the relationship (and you'll be able to make your FK column non-null)
I have a problem with mapping in nhibernate. I am using nhibernate 2.2 version.
Seems like the problem is in mapping but I am not sure this is the cause. Anyway, I have two tables which I would like to map. I created a hbm file for first table and a data transfer object too. All columns were mapped and everything works fine here.
But, now I want to add three bags to this class, which will point to the same table, my second table which I'd like to connect with. I created bags and mapped everything but when I am retrieving my data only one of these bags is filled, and the other ones are left empty, and I get an error "failed to lazily initialize a collection of role: com.organic.mitsu.hib.ModelContent.options - no session or session was closed". And I am 100% sure that my data in database are good. When I remove two bags from my mapping everything works fine, with only one bag left. Here is the hbm file:
<class name="MyFirstClass" table="MyFirstTable">
<id name="ID">
<generator class="native" />
</id>
<property name="ItemOne" />
<property name="ItemTwo" />
<property name="ItemThree" />
<property name="ItemFour" />
<bag name="FirstItems" table="MySecondTable">
<key column="ItemID" property-ref="ItemOne"/>
<one-to-many class="Items" not-found="ignore"/>
</bag>
<bag name="SecondItems" table="MySecondTable">
<key column="ItemID" property-ref="ItemTwo"/>
<one-to-many class="Items" not-found="ignore"/>
</bag>
<bag name="ThirdItems" table="MySecondTable">
<key column="ItemID" property-ref="ItemThree"/>
<one-to-many class="Items" not-found="ignore"/>
</bag>
How should I solve the problem? Is this even possible to do it like this?
And here is the mapping for the MySecondTable:
<class name="Item" table="MySecondTable">
<id name="ID">
<generator class="assigned" />
</id>
<property name="ItemID" />
<property name="Language" />
<property name="Value" />
Actually, the original thing that I was trying to map is with composite element and without the mapping for MySecondTable. I only have a dto class Item, with ItemID and Value columns. I got the same error and the mapping looks like this:
<class name="MyFirstClass" table="MyFirstTable">
<id name="ID">
<generator class="native" />
</id>
<property name="FirstItem" />
<property name="SecondItem" />
<property name="ThirdItem" />
<bag name="FirstItemNames" table="MySecondTable">
<key column="ItemID" property-ref="FirstItem"/>
<composite-element class="Item">
<property name="Value" />
</composite-element>
</bag>
<bag name="SecondItemNames" table="MySecondTable">
<key column="ItemID" property-ref="SecondItem"/>
<composite-element class="Item">
<property name="Value" />
</composite-element>
</bag>
<bag name="ThirdItemNames" table="MySecondTable">
<key column="ItemID" property-ref="ThirdItem"/>
<composite-element class="Item">
<property name="Value" />
</composite-element>
</bag>
Sounds like the SecondItems and ThirdItems are are being fetched lazily after the session was closed, which is not allowed. You need to either force the fetching while the session is active or change the mappings so that lazy fetch (the default) is turned off.
See here for more details.
This is probably incredibly simple, but I just cant see the wood for the trees at the moment.
For brevity, I would like to model a word object, that has related words to it (synonyms), In doing so I could have the following mappings:
<class name="Word" table="bs_word">
<id name="Id" column="WordId" type="Int32" unsaved-value="-1">
<generator class="native">
<param name="sequence"></param>
</generator>
</id>
<property name="Key" column="word" type="String" length="50" />
<many-to-one name="SynonymGroup" class="BS.Core.Domain.Synonym, BS.Core" column="SynonymId" lazy="false"/>
<class name="Synonym" table="bs_Synonym">
<id name="Id" column="SynonymId" type="Int32" unsaved-value="-1">
<generator class="native">
<param name="sequence"></param>
</generator>
</id>
<property name="Alias" column="Alias" type="String" length="50" />
<bag name="Words" cascade="none" lazy="false" inverse="true">
<key column="SynonymId" />
<one-to-many class="Word" />
</bag>
Mapping it like this would mean for a given word, I can access related words (synonyms) like this:
word.SynonymGroup.Words
However I would like to know if it is possible to map a bag of objects on an instance of a word object...if that makes sense, so I can access the related words like this:
word.Words
I've tried playing around with the map element, and composite elements, all to no avail - so I was wondering if some kind person could point me in the right direction?
ta,
kmoo01
This would map a Word entity with a collection of Words (Synonyms):
<class name="Word">
<id ...>
<generator .../>
</id>
<set name="Synonyms" cascade="all">
<key />
<many-to-many class="Word" />
</set>
</class>
You can customize table names in the class and set elements, and column names in the key and many-to-many elements as needed.
Note that I've used set instead of bag, as it fits the semantics better. You can map it to an ICollection<Word> or Iesi.Collections.Generic.ISet<Word>.
I'm new to nhibernate so this should be easy. I have a mapping file as below although I deleted some fields that aren't relevant to this question. The streamfields class contains a bag of fieldmappings. I want the join to be on field_no column but the sql that is sent is on the id field (str_fld_id") as seen below.
I see what the below sql is doing but it's not what I wanted. It's trying to query the field_mappings table based on the values found in the id column str_fld_id in the StreamFields class when I thought it was clear I wanted the field_no to be used on both ends. I say I thought it was clear because the mapping for the field_mapping class has the below attribute and they both have the same named field
Below is in my FieldMappings mapping file.
<many-to-one name="FieldNo" cascade="none" column="`Field_No`" not-null="true">
Sql sent
NHibernate: SELECT fkfieldmap0_.[field_no] as field5_1_, fkfieldmap0_.[Mapping_Id] as Mapping1_1_, fkfieldmap0_.[Mapping_Id] as Mapping1_3_0_, fkfieldmap0_.[Std_fld_Id] as Std2_3_0_, fkfieldmap0_.[Field_Position] as Field3_3_0_, fkfieldmap0_.[Field_No] as Field4_3_0_ FROM [Field_Mappings] fkfieldmap0_ WHERE fkfieldmap0_.[field_no]=#p0; #p0 = '20'
StreamFields mapping
<hibernate-mapping xmlns="urn:nhibernate-mapping-2.2">
<class name="DataTransfer.StreamFields,DataTransfer" table="`stream_fields`" lazy="true">
<id name="StrFldId" column="`str_fld_id`" type="int">
<generator class="native" />
</id>
<property type="int" not-null="true" name="FieldNo" column="`field_no`" />
<many-to-one name="StreamId" cascade="none" column="`stream_Id`" />
<bag name="FkFieldMappingsStreamFields" inverse="true" lazy="false" cascade="all">
<key column="`field_no`" />
<one-to-many class="DataTransfer.FieldMappings,DataTransfer"/>
</bag>
</class>
[Edited - with old comments]
Okay, i think i finally got you right and i might admit the problems i had understanding what you want took me a while and result of the lack of information you provided. In the future please provide the mapping of both tables clarify on the point wheather it is a mapping or a query issue. Thx.
IMO you have misunderstood the idea of a parent/child-relation.
The bag you mentioned like to have within the StreamFields class shouldn't be a bag but a direct association. Like this:
<class name="DataTransfer.StreamFields,DataTransfer" table="stream_fields" >
<id name="StrFldId" column="str_fld_id" type="int">
<generator class="native" />
</id>
<property type="int" not-null="true" name="FieldNo" column="field_no" />
<many-to-one name="FieldMapping" class="FiueldMapping" column="Field_No" />
</class>
This of course will only work if you have a property of type FiledMapping in your class.
You want to map FieldMapping to the column Field_No within StreamFields class. There can only be one value within this column, so a bag makes no sense at all. If you want to have a bag of course you can keep it the way it already worked but be aware that the 'key-column' within the bag refers to the child table - in an other way it makes no sense cause a ForeignKey has to map to a PrimaryKey on its parent table. This ensures it is unique and set.
I really don't want to rant but would strongly encourage you to review the hibernate reference about collection mapping to get a deeper clue however.
Hopely this will solve your problem.
Below are the mappings for the classes.
<?xml version="1.0" encoding="utf-8"?>
<hibernate-mapping xmlns="urn:nhibernate-mapping-2.2">
<class name="DataTransfer.StreamFields,DataTransfer" table="`stream_fields`" lazy="true">
<id name="StrFldId" column="`str_fld_id`" type="int">
<generator class="native" />
</id>
<property type="string" length="50" name="FieldName" column="`field_name`" />
<property type="int" name="InputFieldPosition" column="`input_field_position`" />
<property type="int" name="Start" column="`start`" />
<property type="int" name="Width" column="`width`" />
<property type="string" length="50" name="Datatype" column="`datatype`" />
<property type="int" not-null="true" name="FieldNo" column="`field_no`" />
<property type="int" name="FieldOrder" column="`field_order`" />
<property type="int" name="StdId" column="`Std_Id`" />
<many-to-one name="StreamId" cascade="none" column="`stream_Id`" />
<bag name="FkFieldMappingsStreamFields" inverse="true" lazy="false" cascade="all">
<key column="`field_no`" />
<one-to-many class="DataTransfer.FieldMappings,DataTransfer"/>
</bag>
</class>
</hibernate-mapping>
<?xml version="1.0" encoding="utf-8"?>
<hibernate-mapping xmlns="urn:nhibernate-mapping-2.2">
<class name="DataTransfer.FieldMappings,DataTransfer" table="`Field_Mappings`" lazy="false">
<id name="MappingId" column="`Mapping_Id`" type="int">
<generator class="native" />
</id>
<property type="int" name="StdFldId" column="`Std_fld_Id`" />
<property type="int" name="FieldPosition" column="`Field_Position`" />
<many-to-one name="FieldNo" cascade="none" column="`Field_No`" not-null="true" property-ref="FieldNo" />
</class>
</hibernate-mapping>
To make things easy on myself, there is one record in stream_fields and the field_no value is 1 and 20 is the value in StrFldId.
SELECT fkfieldmap0_.[field_no] as field5_1_, fkfieldmap0_.[Mapping_Id] as Mapping1_1_, fkfieldmap0_.[Mapping_Id] as Mapping1_3_0_, fkfieldmap0_.[Std_fld_Id] as Std2_3_0_, fkfieldmap0_.[Field_Position] as Field3_3_0_, fkfieldmap0_.[Field_No] as Field4_3_0_ FROM [Field_Mappings] fkfieldmap0_ WHERE fkfieldmap0_.[field_no]=#p0; #p0 = '20' –