hibernate-mapping

问题 I have table with a column as NVARCHAR2 , and I have build my object with hibernate annotations, When i want to insert into DB or fetch from DB the result is something like that "???????", I have implemented a custom Dialect as follows but it did not work. public class CustomOracleDialect extends Oracle10gDialect{ public CMSCustomOracleDialect() { registerHibernateType( Types.NVARCHAR, Hibernate.STRING.getName() ); registerColumnType( Types.VARCHAR, "nvarchar2($1)" ); registerColumnType(

问题 I have a Grails 1.3.7 domain class that is declared like this: class Document { String url Map metadata = new HashMap() static constraints = { url(nullable:false, blank: false, maxSize: 2048) metadata() } } The schema that is generated looks like this: +-------------+--------------+------+-----+---------+----------------+ | Field | Type | Null | Key | Default | Extra | +-------------+--------------+------+-----+---------+----------------+ | id | bigint(20) | NO | PRI | NULL | auto_increment |

问题 There is a one to many relationship between College & student entities. College @Entity public class College { private int collegeId; private String collegeName; private List<Student> students; @Id @GeneratedValue public int getCollegeId() { return collegeId; } public void setCollegeId(int collegeId) { this.collegeId = collegeId; } public String getCollegeName() { return collegeName; } public void setCollegeName(String collegeName) { this.collegeName = collegeName; } @OneToMany(targetEntity

问题 I am using Spring transaction management to control a application with hibernate, it uses two instance of threads to access concurrency database and modify one table. It is ensuring that the values are conserved. The table before is: quantidade_livro_id | quantidade | livro_id | tt ---------------------+------------+----------+---- 7 | 100 | 3 | as 5 | 100 | 1 | as 6 | 100 | 2 | as And the table after: quantidade_livro_id | quantidade | livro_id | tt ---------------------+------------+-------

问题 I am fairly new to Hibernate and need some help with hibernate-mapping. I have 4 different classes which I want to map into one table, of which the primary key consists of attributes from 2 different classes. At the same time, I want to map only selected attributes from each class into a local database. I wish to avoid JPA annotations and define the mapping style in a hbm.xml file instead. How do I do that? Take the following example: public class Tenant implements Serializable { private

问题 I am using Hibernate as ORM for my project. I use mysql Database I have a table "Products" inside DB "catalog". I have put the @Table(name="Products",schema="catalog") annotation for the entity Products in my application. However when I try to run the application I get the below exception. Can you please help me resolve this issue? Exception: Exception in thread "main" org.hibernate.HibernateException: Missing table:Products at org.hibernate.cfg.Configuration.validateSchema(Configuration.java

问题 My hbm.xml file is like this: <hibernate-mapping> <class name="pojopackage.WordhelperWordusage" table="WORDHELPER_WORDUSAGE" schema="SOZANA"> <composite-id name="id" class="pojopackage.WordhelperWordusageId"> <key-property name="idwh" type="java.lang.Integer"> <column name="IDWH" /> </key-property> <key-property name="idwu" type="java.lang.Integer"> <column name="IDWU" /> </key-property> <key-property name="type" type="java.lang.Integer"> <column name="TYPE" /> </key-property> </composite-id>

问题 I have some Java/Hibernate code that works just fine on my local machine with the database I have installed. However, I've uploaded the code to the Internet on a Glassfish server and I cannot get it to connect to the database associated with that server. I don't think it's a Java problem. I think it's related to the Hibernate settings, as I felt I had to change the address of the database since the code is no longer talking to the database on my machine. Can anyone helpo me? First, here is

问题 I have a table called group , that I am trying to map using hibernate for DB2 and HSQLDB. Table name group is a reserved word and it must be quoted in HSQLDB. However DB2 does not like quoted table name. So this mapping works in HSQLDB but not in DB2: @Entity @Table(name="`group`") public class Group { Mapping results in following error in DB2 (making a query that involves Group table): Caused by: com.ibm.db2.jcc.b.SqlException: DB2 SQL error: SQLCODE: -204, SQLSTATE: 42704, SQLERRMC: SCHEMA

问题 In our project we have a constraint of not having the luxury to alter the table structure already in place. The tables are highly denormalized in nature. We have come up with good POJOs for the application. We have the Entity beans generated out of the exiting tables. Now we have to map the POJOs to the entities so that we can persist. Ultimately, we combine a good POJO with a bad table. Any thoughts on options/alternatives/suggestions to this approach? 回答1: Hibernate/JPA(2) has a rich set of