Missing sequence or table: hibernate_sequence

Question

I am new to hibernate and postgres. Actually I am trying to map potgres database using Hibernate. This is my table stucture in postgresql

CREATE TABLE employ         


        

Answer 1

You haven't posted the important bit: the Employee class.

But my guess is that your Employee class is using @GeneratedValue() without specifying the sequence to use. So, Hibernate uses its default name: hibernate_sequence.

You can supply a sequence name as part of the GeneratedValue annotation. eg.

@GeneratedValue(strategy=SEQUENCE, generator="employee_id_seq")

Answer 2

In your domain or Model object annotate the id field as below and it should work. For me the GenerationType.AUTO failed

@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
private int id;

Answer 3

If you don't use annotation you should change YourClass.hbm.xml file.

Your ID section should be:

<id name="id" type="int" column="id">
     <generator class="sequence">
         <param name="sequence">employee_id_seq</param>
     </generator>
</id>

File sample:

<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE hibernate-mapping PUBLIC 
 "-//Hibernate/Hibernate Mapping DTD//EN"
 "http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd"> 

<hibernate-mapping>
   <class name="Employee" table="EMPLOYEE">
      <meta attribute="class-description">
         This class contains the employee detail. 
      </meta>
      <id name="id" type="int" column="id">
         <generator class="sequence">
             <param name="sequence">employee_id_seq</param>
         </generator>
      </id>
      <property name="firstName" column="first_name" type="string"/>
      <property name="lastName" column="last_name" type="string"/>
      <property name="salary" column="salary" type="int"/>
   </class>
</hibernate-mapping>

Answer 4

You can do two things. One is to just manually create a blank hibernate_sequence table postgresql. Two, most likely there is a conflict with the user account permissions not allowing grails to create that table.

Answer 5

If you encounter this with Spring Boot or Spring boot/Hibernate Migration then potentially you can try the following

https://mkyong.com/spring-boot/spring-boot-mysql-table-db_name-hibernate_sequence-doesnt-exist/

Answer 6

Simple solution :

create hibernate_sequence table as :

"create sequence <schema>.hibernate_sequence"