hibernate-mapping

问题 I have domain Classes - User, Role, Group, Group Role User Domain private long id, private String userName, private String password, Set<Role> roles = new HashSet<Role>(); User.hbm.xml <hibernate-mapping package="uk.co.jmr.sdp.domain"> <class name="User" table="user"> <id name="id" unsaved-value="-1"> <generator class="native"/> </id> <property name="userName" column="user_name"/> <property name="password" column="password"/> <property name="emailId" column="email_id"/> <set name="roles"

问题 Hi i have many to many mapping with extra columns in the join table. table structure look like this. table vendor{vendor_id, vendor_name, vendor_password, etc...} table student{student_id, student_name, student_password, etc..} table test{test_id, test_subject, test_price,test_level, etc..} Relations as follows vendor to test --> many-to-many student to test --> many-to-many link table vendor_student_test{vendor_id, student_id, test_id, purchasedDate, assignedDate, writtenDate, result} i

问题 I have two related entities, Institution and Registration, such that there is a many-to-one relationship between Registration and Institution. Thus we should be able to have registration entries for a single institution. The entities and relationship mapping: @Entity public class Registration{ @NotNull @ManyToOne(optional=false) @JoinColumn(updatable=false, insertable=false) private Institution institution; } @Entity public class Institution{ @OneToMany(cascade={CascadeType.REMOVE,

问题 I have two schema(claim and policy). For both schema am using same Entity class. My problem is, claim schema has column city but policy schema does have city column. So If I use entity class by policy schema I get error. is this only the way to change the Entity class for each schema ? or is it possible to maintain the different schema in same entity class? My Entity class : @Entity @Table(name = "Table_name") public class X { @Id @GeneratedValue(strategy=GenerationType.AUTO) @Column(name =

问题 Trying to learn Hibernate, i am trying to learn how to execute NamedQuries but evertime i am getting Exception in thread "main" org.hibernate.MappingException: Named query not known .Please help me out here Error ( only the message, not showing complete stack ) Exception in thread "main" org.hibernate.MappingException: Named query not known: hibernate_tut_emp.Employee.FindCountOfNames at org.hibernate.internal.AbstractSessionImpl.getNamedQuery(AbstractSessionImpl.java:177) at org.hibernate

问题 I have two tables in our database that need mapped. The first is a Student table. It looks something like this: id first_name last_name major_code_1 major_code_2 And the Major table is like this: id description I need to map the major codes of the student, where major_code_1 and major_code_2 point to an id in the Major table. How could I do this? Thanks! 回答1: Here is a simple model which maps to your schema: class Student { String firstName String lastName Major firstMajor Major secondMajor

问题 The ideal place for Hibernate configuration files (.hbm.xml) is .../tomcat/webapps/projectName/WEB-INF/classes/hbm But I want to place those configurations settings in a different location, say /usr/local/properties/hibernate How can I do that? If I place that configuration files in that location and if I start Tomcat then it gives me an error on loading that configurations saying hibernate.cfg.xml not found 回答1: To configure location of .cfg.xml file use Configuration.configure(File) instead

问题 I try to retrieve a list with some fields from Contact and also a list of phones. For this, I'm using a query to Contacts; Also I've created a DTO with only that fields that I need. The query is: final StringBuilder query = new StringBuilder(); query.append("SELECT new com.tim.core.dto.client.MinimalContactDTO(c.id, c.version, c.name, c.title, c.email, c.createdDate, c.phones) " + " from CONTACT c "); query.append("where "); query.append("( c.localRecordStatus IS NULL "); query.append("OR c

问题 hibernate xml mapping file does not support default value. So when i try to create a column with default value in mysql, then i run the hibernate save() method without setting the column value. the default value cannot be generated. i have done some search. according to this post: https://forums.hibernate.org/viewtopic.php?t=171&highlight=default+value&sid=84a014fd93dd9b680afc606f616ca4f6 it said hibernate does not support default value. we can use trigger instead. Any way we can do this

问题 Is there a way to make a field non-persistent at update operation but persistent at create operation with JPA - Hibernate 4? I tried it in this way @Transient @Id @Column(name = "USER_NAME", nullable = false, length = 75) private String userName; but with @Transient annotation the field will be transient across all CRUD operations and I want a way to specify that only on this operation is persistent (create). Is there a way to do this? Thanks! 回答1: As explained in this article, you need to