The technical principles of the ORMLITE JDBC framework in database access

The technical principles of the ORMLITE JDBC framework in database access Summary: ORMLITE is a powerful and easy to use Java object relationship mapping (ORM) library, which provides a simple way to database operations in the Java application.This article explores the technical principles of the ORMLITE JDBC framework, including database connection, table mapping and SQL query, and provides corresponding Java code examples. 1 Introduction ORM (object relationship mapping) is a programming technology that is used to map the object -oriented programming language and the relationship database.The ORM library can hide the complexity of the database operation, enabling developers to use object -oriented code for database operations. ORMLITE is a popular Java Orm library, which provides a simple and intuitive API for database operations in Java applications.It has the characteristics of convenient use, easy integration and good performance. This article will explore the technical principles of the ORMLITE JDBC framework to help readers better understand the role of the framework in database access. 2. Database connection ORMLITE is connected to the database by providing a database connection class.Developers can establish a connection through this class with different types of databases (such as MySQL, SQLITE, etc.).Below is an example of connecting to the MySQL database using ORMLITE: // Create a connection of a MySQL database String databaseUrl = "jdbc:mysql://localhost:3306/mydatabase"; String username = "myuser"; String password = "mypassword"; ConnectionSource connectionSource = new JdbcConnectionSource(databaseUrl, username, password); 3. Table mapping One of the core functions of the ORM library is to map the Java object to the database table.ORMLITE uses simple annotations to implement the mapping relationship between objects and tables.The following is an example: @DatabaseTable(tableName = "books") public class Book { @DatabaseField(id = true) private int id; @DatabaseField(columnName = "title") private String title; @DatabaseField(columnName = "author") private String author; // omit the creation function and getter/setter method } In the above example, the annotation of `@databasetable` is used to specify the table name, and the annotation of`@databasefield` is used to specify the mapping relationship of each field.Oremlite will automatically create a database table corresponding to the Java object. 4. SQL query With ORMLITE, developers can use object -oriented API to perform SQL query.The following is an example: // Create a query builder Dao<Book, Integer> bookDao = DaoManager.createDao(connectionSource, Book.class); QueryBuilder<Book, Integer> queryBuilder = bookDao.queryBuilder(); // Set the query condition queryBuilder.where().eq("author", "John Smith"); // Execute the query List<Book> books = queryBuilder.query(); In the above example, we first created a query builder, and then set the query condition with the `where` method (here is a book for the author" John Smith "), and finally executed the query and saved the result in the` Books` list. 5 Conclusion The technical principles of the ORMLITE JDBC framework in database access mainly include database connections, table mapping, and SQL query.It provides a simple and intuitive API that allows developers to easily perform database operations.This article demonstrates the use of ORMLITE through the example code, and hopes to provide readers with some basic understanding of the technical principles of the framework. Note: This article only involves some basic concepts and operations of ORMLITE. For more advanced characteristics and usage, please refer to the corresponding official documents and materials. references: -Omlite official document: http://ormlite.com/ -Omlite github warehouse: https://github.com/j256/ormlite-core