java - Hibernate OneToMany MySQLIntegrityConstraintViolationException: Duplicate entry -

i have 2 java hibernate entities:

@entity public class match_soccer extends match{     @id     @generatedvalue(strategy=generationtype.auto)     private int mid;      ... 

and other one:

@entity public class algo {     @id     @generatedvalue(strategy=generationtype.auto)     private int id;      @onetomany     private list<match_soccer> matches = new arraylist<match_soccer>();      ... 

and if try save 2 different algo entities matches list duplicate entry '6028' key 'uk_auyvi1qkpdtaqrpuyv9je5rda' exception.

hibernate create in database 3 tables: algo match_soccer , table:

algo_match_soccer columns: algo1_id    int(11) matches_mid int(11) pk 

my goal assign list of matches algo. matches can in 2 different algo objects.

algo a1 = new algo(); algo a2 = new algo(); soccerdao sd = new soccerdao(); list<match_soccer> ms = sd.getmatches(datefrom,dateto); // matches database a1.setmatches(ms); a2.setmatches(ms); 

i use function insert:

public void insertalgo(algo1 a){      try {                    session.begintransaction();         session.save(a);         session.gettransaction().commit();     }     catch (runtimeexception e) {         session.gettransaction().rollback();         session.clear();         throw e; } 

matches can in 2 different algo objects

then don't have onetomany association, manytomany association. since algo has several matches, , match belongs several algos.

change mapping, , change database schema accordingly: pk of join table should pair of ids, , not match id.