Hi all,

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 (<id name="StrFldId" column="`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.

Can someone help me out? Thanks.

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>
</hibernate-mapping>

To make this problem more clear. the name of the field isn't mentioned in the query but it used the values found in the field called 'StrFldId' to try and look up the field mappings when it should be using the values from the field_no field.

There is no value 20 in the field_no field but that value is found in the strfldid field.

So, the below query is using the values in StrFldId when I thought it would use field_no values.

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' –

spacecowboy, check out http://www.rmfusion.com. There are some useful code examples on NHibernate.NET under the Open Source section.

Afaik, you can't do that. A collection mapping always uses the id of the parent for querying the child records. Is there a special reason why you want/need to use a separate column for that ? It seems to be a redundant information.

Major newbie here too. If I'm understanding you right then try this

in your bag do

<key column="`field_no`" property-ref="`field_no`"/>