hbm2ddl

问题 Dear all I am using Hibernate with hbm2ddl. I don't like that for one relationship foreign key constraints get created. Unfortunately I could not achieve it so far. I tried it with Hibernate and JPA annotations, had no luck. Any hints? I am using Hibernate 4.3.1 and mysql 5.6 @Entity class Artikel { ... @OneToMany(fetch=FetchType.LAZY, mappedBy="artikel") @NotFound(action=NotFoundAction.IGNORE) private List<Bild> images; } import javax.persistence.Entity; import javax.persistence.FetchType;

问题 I am setting up a project that uses hibernate, and I am writing the classes and adding annotations to avoid writing .hbm.xml files. I am also trying to use maven hibernate3 plugin specifically hbm2dao and hbm2ddl for dao and database creation but I get the error failed: Unable to load class declared as <mapping class=package.ClassName..... hibernate.cfg.xml follows: <hibernate-configuration> <session-factory name="jndi/composite/SessionFactory"> <property name="hibernate.c3p0.max_size">20<

问题 I am setting up a project that uses hibernate, and I am writing the classes and adding annotations to avoid writing .hbm.xml files. I am also trying to use maven hibernate3 plugin specifically hbm2dao and hbm2ddl for dao and database creation but I get the error failed: Unable to load class declared as <mapping class=package.ClassName..... hibernate.cfg.xml follows: <hibernate-configuration> <session-factory name="jndi/composite/SessionFactory"> <property name="hibernate.c3p0.max_size">20<

问题 Why would hbm2ddl ignore the @Column annotation ? This is my class :- import javax.persistence.Column; import javax.persistence.Entity; import javax.persistence.GeneratedValue; import javax.persistence.Id; import javax.persistence.Table; @Entity @Table(name = "BASETEMPLATE") public class BaseTemplate implements IBaseTemplate { private Integer id; @Column(name="TEMPLATENAME") private String templateName; @Column(name="BASETEMPLATEID") private Integer baseTemplateId; @Id @GeneratedValue @Column

问题 Why would hbm2ddl ignore the @Column annotation ? This is my class :- import javax.persistence.Column; import javax.persistence.Entity; import javax.persistence.GeneratedValue; import javax.persistence.Id; import javax.persistence.Table; @Entity @Table(name = "BASETEMPLATE") public class BaseTemplate implements IBaseTemplate { private Integer id; @Column(name="TEMPLATENAME") private String templateName; @Column(name="BASETEMPLATEID") private Integer baseTemplateId; @Id @GeneratedValue @Column

问题 How does hibernate generate foreign key constraint names? If i do not define a name hibernate generates something like this CONSTRAINT fk_2ocepcfwpr1v18dg1ieoe6bau how is this name generated? Maybe from MD5 hash of field names or something like that? I need to know if the name is equal on all instances. 回答1: Hibernate generates a constraint name by concatenating table and properties names and convert the result to MD5 . It is needed, because of the constraint names length restriction in some

问题 The database table is NOT auto-created by the <property name="hbm2ddl.auto">update</property> settings in hibernate-cfg.xml , with the following combination: Java 8 + Tomcat 8 + MySQL + Hibernate 5 Java version: java version "1.8.0_45" Java(TM) SE Runtime Environment (build 1.8.0_45-b14) Java HotSpot(TM) 64-Bit Server VM (build 25.45-b02, mixed mode) MySQL version: mysql Ver 14.14 Distrib 5.6.16, for osx10.7 (x86_64) using EditLine wrapper Tomcat version: apache-tomcat-8.0.22 pom.xml snippets

问题 I am using hyperjaxb to generate Java classes from an xsd file. How can I configure it to generate hibernate annotations, and to trigger hbm2ddl to create a MySQL database with tables for the generated classes? I downloaded the purchase order sample for hibernate from this link, then navigated to the target directory in cmd.exe and ran mvn clean install , but the resulting folders did not contain any java classes, and this also did not contain any hibernate/MySQL. I would like to get a

问题 I currently have the following in my domain model: @Inheritance(strategy = InheritanceType.TABLE_PER_CLASS) @Entity abstract class Item { @ManyToOne @ForeignKey(name="FK_ITEM_ORG") @JoinColumn(name="ORG_ID") private Organization org } @Table(name = "ItemA") public class ItemA extends Item {} @Table(name = "ItemB") public class ItemA extends Item {} Hibernate's HBM2DDL creates 2 tables for this mapping: ItemA and ItemB . Both have the ORG_ID column and a foreign key to the Organization table.

问题 I am developing a Spring/Hibernate/MySql application. The application is not yet in production and I currently use the Hibernate's hbm2ddl feature which is very convenient for managing changes on the domain. I also intend to use Flyway for database migrations. At some point in the future, the application will be put in production for the first time which leads to my first set of questions: What is the best practice to use for schema creation (first time the app is released into production)?