The relationship mapping and database operation skills of the UJO ORM framework

The relationship mapping and database operation skills of the UJO ORM framework introduction: With the growth of the Internet and data, the demand for data -based applications is also increasing rapidly.When developing such applications, we usually need to operate the database, which requires the ORM (object relationship mapping) framework.UJO (Unified Java Objects) is a Java -based ORM framework that provides a simple and powerful way to handle relationship mapping and database operations.This article will introduce the relationship mapping and database operation skills of the UJO ORM framework in detail. Introduction to UJO ORM framework The UJO ORM framework is a tool for processing the mapping relationship between objects and databases.Its goal is to provide a simple and easy way to manage the conversion between the data model and the database.The UJO ORM framework implements a series of ORM functions, including: 1. Object relationship mapping: Establish a mapping relationship between the database table and the Java object; 2. Database operation: provides a set of flexible and powerful APIs for adding, deletion, modification and investigation operations; 3. Affairs management: support the isolation level and roll operation of affairs; 4. Query Language: Support the use of object -oriented query language for database query; 5. Cache mechanism: Provides a cache mechanism to optimize database access performance. 2. Relationship mapping Relationship mapping is one of the core functions of the UJO ORM framework.It can help us convert the object model and the database model.When using the UJO ORM framework, we need to define the relationship between the class and attributes of the Java object and the database table.For example, we can use the following injection to map a Java class to the database table: @Table(name = "users") public class User { @Id @Column(name = "id") private int id; @Column(name = "name") private String name; // getters and setters } In the above example, the@Table annotation is used to specify the name of the database table,@ID annotation is used to identify the attribute as the main key, and@column annotations are used to specify the column name corresponding to the attribute.Through these annotations, the UJO ORM framework can complete the mapping between the object and the database according to the defined relationship. 3. Database operation skills In addition to the relationship mapping, the UJO ORM framework also provides a set of powerful APIs to commonly add, delete and change the operation of databases.The following are several techniques for database operations using the UJO ORM framework: 1. Insert data: User user = new User(); user.setName("John Doe"); UjoManager.getInstance().insert(user); 2. Update data: User user = UjoManager.getInstance().load(User.class, 1); user.setName("Jane Doe"); UjoManager.getInstance().update(user); 3. Delete data: UjoManager.getInstance().delete(User.class, 1); 4. Query data: List<User> users = UjoManager.getInstance().find(User.class, "name = ?", "John Doe"); Through the above code clips, we can see that the UJO ORM framework provides a simple and powerful API for database operations.We can perform operations such as inserting, updating, deleting, and query as needed. Summarize: This article introduces the relationship mapping and database operation skills of the UJO ORM framework.By using the UJO ORM framework, we can easily handle the mapping relationship between objects and databases, and common database operations.I hope this article can help readers better understand and apply the UJO ORM framework.If you need to understand a deeper understanding, it is recommended to refer to the official documentation and example code of the UJO ORM framework.