session cache

-Temporary state: The object has just been created with the new statement and is not persisted and is not in the session cache. A Java object that is in a temporary state is called a temporary object.-Persistent state: has been persisted and added

I. Overview-Temporary state: The object has just been created with the new statement and is not persisted and is not in the session cache. A Java object that is in a temporary state is called a temporary object.-Persistent state: has been persisted

First, briefly describe the differences between Hibernate and JDBC, advantages and disadvantages?JDBC has the advantage of JDBC flexibility over performance compared to hibernate. Hibernate has some advantages in easy learning and ease of use. JDBC

Hibernate hql Query:The criteria query encapsulates the query criteria in an object-oriented manner, but HQL (Hibernate query lanaguage) queries provide richer and more flexible query features. As a result, Hibernate makes the HQL query the official

This article mainly introduces phpsession application details. For more information about php session applications, see the following article, for more information, see Php session advanced application Session is very important in web technology.

Hibernate HQL Query Statement summary1, Entity query:As for the entity query technology, we have already dealt with it many times before, such as the following example:String hql= "from user User";List list=session. CreateQuery (HQL). List ();The

  Sesison interface is the most important persistence manager in hibernate. It can perform basic CRUD operations, execution condition queries,Transaction ControlAnd the lifecycle of the Persistent Object. Single thread, non-shared object.

Hibernate Query Language Query: Criteria queries encapsulate the Query conditions in an object-oriented manner and conform to the programming mindset. However, HQL (Hibernate Query Language) queries provide richer and more flexible Query features,

1. Object Query:The object query technology has already been involved many times before, for example, the following example:String hql = "from user ";List list = session. createquery (hql). List ();The code above is executed to query all the data

HqlHql query:Criteria queries encapsulate the query conditions in an object-oriented manner and conform to the programming mindset. However, hql (Hibernate query language) queries provide richer and more flexible query features, therefore, Hibernate

I. Three states of objects in hibernate1. Transient status (transient)When we generate an entity object from the Java New keyword, the entity object is in a free State, and the object is simply getting a chunk of memory through the JVM and not being

Persisted object PO class state1. Status classification transient transient state: Hibernate's session cache is not stored and no data is in the database. For example, New PO class, no OID value Persistent Persistent state: Hibernate is stored in

Reprinted from: http://www.cnblogs.com/blackdeng/p/7027465.htmlWhat is the session cache?Session cache: In the implementation of the session interface contains a series of collections (list), which are used to save the session

Get and load mode is a record based on IDThe difference between get and load is detailed below, because sometimes it is added in order to compare. 1. Compare the results from the return:A Org.hibernate.ObjectNotFoundException exception is thrown if

Basic concepts of three states:1, temporary State (Transient): Also called Free State, exists only in memory, and there is no corresponding data in the database. Object created with new, it is not persisted, is not in session, the object in this

For the get method, hibernate checks whether the data corresponding to this id exists. First, it searches for the data in the session cache, and then searches for the data in the second-level cache. If no data exists, it queries the database. For

Hibernate object stateInstantaneous (transient): Created by the new operator and not yet associated with the hibernate session. Instantaneous objects are not persisted to the database and are not given persistent identities.Persistent (persistent):

Hibernate is an open-source object relationship ing framework. It implements lightweight object encapsulation for JDBC, so that Java programmers can use the object programming thinking to manipulate the database as they wish. It not only provides

Hql query: Criteria queries encapsulate the query conditions in an object-oriented manner and conform to the programming mindset. However, hql (Hibernate query language) queries provide richer and more flexible query features, therefore, Hibernate

Basic concepts of three states:1, transient State (Transient): Also called Free State, exists only in memory, and there is no corresponding data in the database. Object created with new, it is not persisted, is not in session, the object in this