hibernate mapping

1. Component Mapping Overview A component class is a value type that does not have an object identifier property and does not have a corresponding table in the database and is subordinate only to an instance of another persisted class. Use the component class as a single property of the persisted class Use the component class as the collection property of the persisted class 2. Component Mapping (User-name)

classes maintain the relationship, classes will issue an extra UPDATE statement, to ensure that class and student have a relationship, so load classes when the classes corresponding students can be loaded up. To address this disadvantage, Hibernate provides a second mapping method, bidirectional one-to-many mappings. 2. Bidirectional one-to-manyObject Model DiagramRelational Model Diagrama one-to-many

Here's a second way to implement a one-to-one correlation mapping, the unique Foreign Key association.Unique FOREIGN Key Association: A Foreign Key association, which is intended to be used for many-to-one configurations, but can also be used to represent an affinity relationship if a unique limit is added.A unique foreign Key association is also used in two ways, one-way and two-way. The object model is consistent with the single-direction associated

Attribute Mappings 1) @Column modifier PropertiesUsing the @Column to decorate the Pojo property, you can specify some mapping information at the same time, and the commonly used information is as follows (these @Column properties are optional): Name Specify column names for this column Length Specifies the maximum length of the column, default 255 Nullable Specifies whether this can be null, by defaul

The basic understanding of object-relational mapping (ORM) has been reflected in two previous blogs.ORM Basic UnderstandingOn the mapping scheme of ORMWhat we are learning today is Hibernate's object-relational mapping.several ways to map hibernateBasic MappingConfiguration of mappings in Hibernate in XML, we want to map the object and table to the transformation

here I recorded the corresponding relationship between Hibernate field mappings, which makes it easier to find them later. Hibernate field Type Mapping Hibernate Inner Type corresponding Java type Database SQL type Integer int or Integer INTEGER

maintenance of relationship changes, if the inverse=true is to maintain the relationship between the change of the right reversal, to the other side to deal with, The general one side does not maintain the association relations all is to make the many end to maintain namely sets Inverse=true, in Many-to-one inverse does not support the configuration, the default namely handles the correlation relation the change.For example, when inverse=true, add order to customer and save customer, there will

Write a hibernate example step three: Create an object-relational map fileThe following are the specific implementation steps: Find the Student class sudents we want to persist Build Object-Relational map document Students.hbm.xml: Mapping our entity class to a table in the database (STUDENTS), one level maps each of our properties to a field in a database table, and column name

should also increase constrained= "true"to make the current primary key add a FOREIGN key constraint on the other end of the--class= "Manager" constrained= "true" >class>Manager.hbm.xml Package= "Com.cqupt.dayday" > className= "Manager" table= "manager" > native: Using Database Local mode-class= "Native"/> class= "Department" >class>2: Based on the foreign key mapping 1-1 correlation relation Difference1) Use Many-to-one in entity class

Simple mapping In recent years ORM (Object-relational Mapping, Object-relational mapping, that is, the mapping of entity objects and database tables) technology market is very lively, a variety of persistent framework came into being, the most influential is the Hibernate a

Hibernate mappings: one-to-one correlation　1. Follow the foreign key map2. Follow the primary key mapping　　　Component MappingsThe following is an example of the Employee Account form and the Employee Profile table (a one-to-two relationship between the employee account and the file table), which is described in the following two mapping relationships, and each of

The following is an introduction to hibernate, another way of associating mappings.There are two implementation strategies for one-to-single affinity mappings: primary key affinity mappings and unique foreign Key association mappings.PRIMARY KEY affinity mapping: Let two objects have the same primary key value to justify the one by one correspondence between them; The database table does not have additional

Object-Relational mapping (Object/relation Mapping, or ORM), which arises from the development of object-oriented software development methods, is a technique to solve the phenomenon of non-matching between object-oriented and relational database. Essentially, it's converting data from one form to another. Hibernate, as the representative of an ORM framework, is

Hibernate takes a mapping type as a bridge between Java type and SQL type, corresponding to the type attribute.There are two types: the built-in mapping type and the custom mapping type.One, built-in mapping type :1,JaVA basic types of H