java - @Column insertable, updateble don't go well with Spring JPA? -

scenario : have 3 tables, offer, channel , offer_channels. channel lookup table, i.e, values in table can neither inserted nor updated application. offer can contain 1 or many channels. use channel table values populate dynamic checkboxes. anyways, here have :

@entity @table(name = "offer") @cache(usage = cacheconcurrencystrategy.nonstrict_read_write) public class offer implements serializable {      // offer id     @id     @generatedvalue(strategy = generationtype.auto, generator = "offer_seq_gen")     @column(name = "offer_id")     private long offerid;       @manytomany(cascade = cascadetype.all)     @jointable(name = "offer_channels", joincolumns = { @joincolumn(name = "offer_id") },          inversejoincolumns = { @joincolumn(name = "channel_id") })     private set<channel> channels = new hashset<channel>();    //other fields , corresponding getters , setters  } 

here channel entity :

@entity @table(name = "channel") public class channel implements serializable {      private static final long serialversionuid = 1l;      @notnull     @id     @column(name = "channel_id", insertable=false, updatable=false)     private long channelid;      @column(name = "channel_name", insertable=false, updatable=false)     private string channelname;  //getters , setters  } 

now, when user creates offer, need insert row in offer table , offer_channels tables , nothing(no updates/inserts) channel table. initially, 3 happen, achive "do nothing channel table" part, put insertable=false , updateable=false on channel table columns , worked charm. used plain hibernates this. mean wrote standalone java application , main class add offer useing hibernate's session.save(offer). ran following queries :

  hibernate: insert offer    hibernate: insert offer_channels  

alright, now, have rest service using spring's jpa repository save information , have same domain objects setup. now, when add offer, runs :

hibernate: insert offer  hibernate: insert channel ( failing here obviously. don't want step happen) 

my question : 1. why is trying write channel table though gave insertable=false in domain object, , happening spring jpa setup. hibernate setup works fine. 3. doesn't @jointable/ @onetomany / insertable / updateble , go spring jpa repository ? missing here ?

update :

@service @transactional public class offerservice {      @inject     private offerrepository offerrepository;       public offer saveofferinformation(offer offer) {         log.debug("saving offer info..");         log.debug("offer object :"+offer);         return offerrepository.save(offer);      }  } 

repo :

public interface offerrepository extends jparepository<offer, long> {     list<offer> findbybuysku(string buysku); } 

and in rest service im injecting service , calling it, no business logic in rest service. right im getting , reason is trying insert record channel table:

 exception: "org.springframework.dao.dataintegrityviolationexception"   message: "could not execute statement; sql [n/a]; constraint [pvs_owner.channel_pk]; nested   exception org.hibernate.exception.constraintviolationexception: not execute statement"