Introduction and basic usage of ORMLITE CORE framework
ORMLITE is an open source Java persistence framework for simplifying interaction with the database.It provides a simple and powerful API that allows developers to quickly build and maintain database applications.This article will introduce the basic usage of the ORMLITE CORE framework and provide some Java code examples to help readers better understand. First, we need to understand some basic concepts. 1. Table table (table): The data in the database is stored in the table, each table contains multiple rows and colums. 2. Persistent Object: Map the Java object to the object of the database table.The persistent object contains the attribute corresponding to the columns in the table. 3. DAO (DATA Access Object): Used to perform interactive operations with databases, such as inserting, updating, querying and deleting. Next, we will understand how to create and configure durable classes in the ORMLITE framework, and use DAO to perform database operations. 1. Configuration dependencies: First, we need to add the dependencies of ormlite in the project.You can add the ORMLITE library to the project through Maven or Gradle. 2. Create a persistent class: Create a Java class to represent database tables and persistent objects.In the definition of the class, we can use the annotation to specify the name, column name and other attributes of the form.For example: ``` @DatabaseTable(tableName = "users") public class User { @DatabaseField(columnName = "id", generatedId = true) private int id; @DatabaseField(columnName = "name") private String name; // getters and setters } ``` In the above example, we define a form called "Users" and specify "ID" and "name" as their names.Using the `@databasefield` annotation can specify the mapping relationship between the attribute and the table column. 3. Configure database connection: When the application starts, we need to configure the database connection to interact with the database.For example: ``` public class DatabaseConnection { private static final String DATABASE_URL = "jdbc:mysql://localhost:3306/mydb"; private static final String DATABASE_USERNAME = "username"; private static final String DATABASE_PASSWORD = "password"; public static ConnectionSource getConnection() throws SQLException { return new JdbcConnectionSource(DATABASE_URL, DATABASE_USERNAME, DATABASE_PASSWORD); } } ``` In the above example, we use mysql database and create a database connection through the `jdbcconnectionSource` class. 4. Create DAO: You can perform interactive operations with the database through DAO.For example, we can create a UserDao to perform the operation of the User table.For example: ``` public class UserDao { private Dao<User, Integer> userDao; public UserDao(ConnectionSource connectionSource) throws SQLException { userDao = DaoManager.createDao(connectionSource, User.class); } public User getUserById(int id) throws SQLException { return userDao.queryForId(id); } public void addUser(User user) throws SQLException { userDao.create(user); } public void updateUser(User user) throws SQLException { userDao.update(user); } public void deleteUser(User user) throws SQLException { userDao.delete(user); } } ``` In the above example, we created a UserDao class that contains some common database operation methods.By calling UserDao's method, we can easily perform the operation of the database table. Summarize: ORMLITE CORE is a powerful Java persistence framework. It provides a simple and easy -to -use API, allowing developers to easily interact with the database.This article introduces the basic usage of the ORMLITE CORE framework, including the creation of persistent classes, configuration database connections, and using DAO to perform operations on database tables.Through the ORMLite Core, developers can develop and maintain database applications more efficiently. The above is the introduction and basic usage of the ORMLITE CORE framework.It is hoped that readers can better develop and manage database applications through this framework.