How to annotate MYSQL autoincrement field with JPA annotations

Question

Straight to the point  problem is saving the object Operator into MySQL DB  Prior to save  I try to select from this table and it works  so is connection to db   Here is my Operator object    Entity public class Operator       Id     GeneratedValue    private Long id      private String username      private String password       private Integer active        Getters and setters        To save I use JPA EntityManager   s persist method   Here is some log   Hibernate  insert into Operator  active  password  username  id  values              com mysql jdbc JDBC4PreparedStatement 15724a0  insert into Operator  active password  username  id  values  0   pass    user      NOT SPECIFIED       The way I see it  problem is configuration with auto increment but I can t figure out where   Tried some tricks I ve seen here  Hibernate not respecting MySQL auto increment primary key field But nothing of that worked  If any other configuration files needed I will provide them   DDL   CREATE TABLE  operator      id  INT 10  NOT NULL AUTO INCREMENT   first name  VARCHAR 40  NOT NULL   last name  VARCHAR 40  NOT NULL   username  VARCHAR 50  NOT NULL   password  VARCHAR 50  NOT NULL   active  INT 1  NOT NULL  PRIMARY KEY   id

User · Answer

Using MySQL  only this approach was working for me    Id  GeneratedValue strategy GenerationType IDENTITY  private Long id    The other 2 approaches stated by Pascal in his answer were not working for me

User · Answer

For anyone reading this who is using EclipseLink for JPA 2 0  here are the two annotations I had to use to get JPA to persist data  where  MySequenceGenerator  is whatever name you want to give the generator   myschema  is the name of the schema in your database that contains the sequence object  and  mysequence  is the name of the sequence object in the database    GeneratedValue strategy  GenerationType SEQUENCE  generator  MySequenceGenerator    SequenceGenerator allocationSize 1  schema  myschema    name  MySequenceGenerator   sequenceName    mysequence     For those using EclipseLink  and possibly other JPA providers   it is CRITICAL that you set the allocationSize attribute to match the INCREMENT value defined for your sequence in the database  If you don t  you ll get a generic persistence failure  and waste a good deal of time trying to track it down  like I did  Here is the reference page that helped me overcome this challenge   http   wiki eclipse org EclipseLink Examples JPA PrimaryKey Using Sequence Objects  Also  to give context  here is what we re using   Java 7 Glassfish 3 1 PostgreSQL 9 1 PrimeFaces 3 2 JSF 2 1  Also  for laziness  sake  I built this in Netbeans with the wizards for generating Entities from DB  Controllers from Entities  and JSF from Entities  and the wizards  obviously  do not know how to deal with sequence-based ID columns  so you ll have to manually add these annotations

User · Answer

Please make sure that id datatype is Long instead of String  if that   will be string then  GeneratedValue annotation will not work and the   sql generating for    Id  GeneratedValue strategy GenerationType IDENTITY  private String id   create table VMS AUDIT RECORDS  id   varchar 255    not null auto increment primary key  id        that  needs to be   create table VMS AUDIT RECORDS  id   bigint   not null auto increment primary key  id

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To use a MySQL AUTO INCREMENT column  you are supposed to use an IDENTITY strategy    Id  GeneratedValue strategy GenerationType IDENTITY  private Long id    Which is what you d get when using AUTO with MySQL    Id  GeneratedValue strategy GenerationType AUTO  private Long id    Which is actually equivalent to   Id  GeneratedValue private Long id    In other words  your mapping should work  But Hibernate should omit the id column in the SQL insert statement  and it is not  There must be a kind of mismatch somewhere   Did you specify a MySQL dialect in your Hibernate configuration  probably MySQL5InnoDBDialect or MySQL5Dialect depending on the engine you re using     Also  who created the table  Can you show the corresponding DDL   Follow-up  I can t reproduce your problem  Using the code of your entity and your DDL  Hibernate generates the following  expected  SQL with MySQL   insert  into     Operator      active  password  username   values                 Note that the id column is absent from the above statement  as expected    To sum up  your code  the table definition and the dialect are correct and coherent  it should work  If it doesn t for you  maybe something is out of sync  do a clean build  double check the build directory  etc  or something else is just wrong  check the logs for anything suspicious    Regarding the dialect  the only difference between MySQL5Dialect or  MySQL5InnoDBDialect is that the later adds ENGINE InnoDB to the table objects when generating the DDL  Using one or the other doesn t change the generated SQL

User · Answer

If you are using Mysql with Hibernate v3 it s ok to use GenerationType AUTO because internally it will use GenerationType IDENTITY  which is the most optimal in for MySQL   However in Hibernate v5  It has changed  GenerationType AUTO will use GenerationType TABLE which generates to much queries for the insertion   You can avoid that using GenerationType IDENTITY  if MySQL is the only database you are using  or with these notations  if you have multiple databases     GeneratedValue strategy   GenerationType AUTO  generator    native    GenericGenerator name    native   strategy    native

User · Answer

As you have define the id in int type at the database creation  you have to use the same data type in the model class too  And as you have defined the id to auto increment in the database  you have to mention it in the model class by passing value  GenerationType AUTO  into the attribute  strategy  within the annotation  GeneratedValue  Then the code becomes as below    Entity public class Operator      Id    GeneratedValue strategy   GenerationType AUTO    private int id     private String username     private String password     private Integer active       Getters and setters

User · Answer

I tried every thing  but still I was unable to do that  I am using mysql  jpa with hibernate  I resolved my issue by assigning value of id 0 in constructor Following is my id declaration code   Id  Column name  id  updatable false nullable false   GeneratedValue strategy   GenerationType IDENTITY  private Long id

User · Answer

can you check whether you connected to the correct database  as i was faced same issue  but finally i found that i connected to different database   identity supports identity columns in DB2  MySQL  MS SQL Server  Sybase and HypersonicSQL  The returned identifier is of type long  short or int   More Info   http   docs jboss org hibernate orm 3 5 reference en html mapping html mapping-declaration-id

User · Answer

same as pascal answered  just if you need to use  AUTO for some reason you just need to add in your application properties   spring jpa show-sql true spring jpa properties hibernate format sql true spring jpa hibernate ddl-auto   update

User · Answer

If you are using MariaDB this will work  Id  GeneratedValue strategy   GenerationType IDENTITY   Column name    quot id quot   updatable   false  nullable   false  private Long id   For more  you can check https   thorben-janssen com hibernate-tips-use-auto-incremented-column-primary-key

[java] How to annotate MYSQL autoincrement field with JPA annotations

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