Duplicate key or integrity constraint violation message from server in Hibernate

Question

I'm new to Hibernate. I'm trying to insert records into my MySQL DB. The first record was inserted properly when I run the Java application, and when I change the details in the code and try to run it again. It throws me error of Duplicate key or integrity constraint. My XML is

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN" "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<hibernate-mapping>
<class name="com.college.Student" table="STUDENT">
<id column="ID" name="id" type="long" />
<property column="STUDENT_NAME" name="name" type="string" />
<property column="DEGREE" name="degree" type="string" />
<property column="ROLL" name="roll" type="string" />
<property column="PHONE" name="phone" type="string" />
</class>
</hibernate-mapping>

I guess I need to change in this configuration file or Hibernate.cfg.xml because its a primary key . Please suggest me.

Following is the error

WARN: SQL Error: 1062, SQLState: 23000
Feb 18, 2016 11:49:36 AM org.hibernate.engine.jdbc.spi.SqlExceptionHelper logExceptions
ERROR: Duplicate key or integrity constraint violation message from server:  "Duplicate entry '0' for key 'PRIMARY'"
Feb 18, 2016 11:49:36 AM  org.hibernate.engine.jdbc.batch.internal.AbstractBatchImpl release
INFO: HHH000010: On release of batch it still contained JDBC statements
Feb 18, 2016 11:49:36 AM org.hibernate.internal.SessionImpl$5 mapManagedFlushFailure
ERROR: HHH000346: Error during managed flush [could not execute statement]
Exception in thread "main"  org.hibernate.exception.ConstraintViolationException: could not execute statement
at org.hibernate.exception.internal.SQLStateConversionDelegate.convert(SQLStateConversionDelegate.java:112)

score 0 · Accepted Answer · answered Feb 18 '16 at 06:31

0

Seems like you haven't incremented your primary key column, you will have to do something like this

<id column="ID" name="id" type="long" >
     <generator class="increment" />
</id>

answered Feb 18 '16 at 06:31

Vihar

3,626
2
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Whats the diff between class="increment" and class="native" – Syed Feb 18 '16 at 06:37
@Syed looks like `native` is [not a good choose](http://stackoverflow.com/questions/1838520/hibernate-problems-with-auto-increment-id-mysql-5) for MySQL – v.ladynev Feb 18 '16 at 06:43
@v.ladynev Why? Any special reason? – Syed Feb 18 '16 at 06:45
@Syed See the link :) – v.ladynev Feb 18 '16 at 06:45
@v.ladynev what link? – Syed Feb 18 '16 at 06:48
@Syed [not a good choose](http://stackoverflow.com/questions/1838520/hibernate-problems-with-auto-increment-id-mysql-5) – v.ladynev Feb 18 '16 at 06:49

score 0 · Answer 2 · answered Feb 18 '16 at 06:34

0

You need to give generator for primary key of your table which will auto generated.

<id name="id" type="int" column="id">
     <generator class="native"/>
  </id>

Read this

answered Feb 18 '16 at 06:34

Pramod Gaikwad

185
1
2
16

better to use JPA, it will save your time to maintain XML files. – Pramod Gaikwad Feb 18 '16 at 06:36

v.ladynev · Answer 3 · 2016-02-18T08:52:25.257

You need to have an auto increment for an id column.

For MySQL the best choice is to use identity generator, because of MySQL supports it natively.

<id column="ID" name="id" type="long">
    <generator class="identity"/>
</id>

Hibernate will create a table with auto_increment column and MySQL will care about auto increment id

create table STUDENT (
    ID bigint not null auto_increment,
    ...
)

Using other generators is not optimal, because of Hibernate will use additional queries and a table (hibernate_sequence) to increment id.

Duplicate key or integrity constraint violation message from server in Hibernate

3 Answers3