The best practical guide to Korm framework in the Java class library

The Korm framework is a lightweight ORM (object relationship mapping) framework for Java libraries.It provides a simple and easy -to -use API, enabling developers to perform database operations more easily.This article will introduce the best practical guide to the Korm framework, including related programming code and configuration description. ### 1. Introduce Korm dependencies First, we need to introduce the dependencies of the Korm framework in the construction file of the project.We can add the following code to the pom.xml file of the Maven project: <dependencies> <dependency> <groupId>org.korm</groupId> <artifactId>korm</artifactId> <version>1.0.0</version> </dependency> ... </dependencies> ### 2. Configure database connection Before using the Korm framework, we need to configure the database connection information.You can add the following configuration items to the configuration file of the project: properties # Database connection configuration korm.jdbc.url=jdbc:mysql://localhost:3306/mydb korm.jdbc.username=root korm.jdbc.password=123456 ### 3. Create a physical class Next, we need to create a physical class corresponding to the database table.The physical class uses annotations to map the database table and field.For example, we can create a physical class called User, which contains ID, name, and Age field: @Table(name = "user") public class User { @Id private Long id; @Column(name = "name") private String name; @Column(name = "age") private Integer age; // omit the getter and setter method } ### 4. Execute the database operation Now, we can use the Korm framework for database operations.Here are some common database operation examples: -Stch -in data: User user = new User(); user.setId(1L); user.setName("John"); user.setAge(25); Korm.insert(user); - update data: User user = Korm.select(User.class).where("id = ?", 1L).fetchOne(); user.setName("John Doe"); user.setAge(30); Korm.update(user); - Query data: List<User> users = Korm.select(User.class).where("age > ?", 18).fetch(); - delete data: User user = Korm.select(User.class).where("id = ?", 1L).fetchOne(); Korm.delete(user); ### 5. Advanced query The Korm framework also provides some advanced query functions, making the database query more flexible and powerful. -Step: List<User> users = Korm.select(User.class).orderBy("age desc").fetch(); -Pagod: List<User> users = Korm.select(User.class).limit(10).offset(0).fetch(); -Lor related query: @Table(name = "user") public class User { @Id private Long id; @Column(name = "name") private String name; @ManyToOne @JoinColumn(name = "group_id") private Group group; // omit the getter and setter method } @Table(name = "group") public class Group { @Id private Long id; @Column(name = "name") private String name; // omit the getter and setter method } // Query the user and its group List<User> users = Korm.select(User.class).fetch(); ### 6. Affairs management Korm framework supports transaction management to ensure the atomicity and consistency of database operations.The following is an example of a transaction: Korm.transaction(() -> { User user1 = new User(); user1.setId(1L); user1.setName("John"); user1.setAge(25); Korm.insert(user1); User user2 = new User(); user2.setId(2L); user2.setName("Jane"); user2.setAge(30); Korm.insert(user2); }); In the above code, the insertion operation of the two users will be performed in the same transaction.If any insertion operation fails, the entire transaction will be rolled back. ### Summarize By using the Korm framework, we can more conveniently perform the ORM operation of the Java class library.This article introduces the best practical guide for the Korm framework, including the introduction of dependence, configuration database connection, creating physical class, execution database operations, and advanced inquiries and transaction management.I hope these guidelines can help you better use the Korm framework for development.