Apache Derby database engine and embedded JDBC driver's application principle analysis in the Java library

The Apache Derby database engine is a relationship database management system (RDBMS) completely written by Java, which provides an efficient, lightweight embedded database solution.Compared with the traditional database engine, Derby has smaller memory occupation and faster response speed, while supporting standard SQL syntax and ACID transactions. Derby's embedded JDBC driver enables applications to directly embed and manage Derby database without extra database servers.This embedded method makes the deployment and management of the application easier, and it can also improve the performance and security of the application. The main steps of using the Derby database engine and embedded JDBC drive are as follows: 1. Import JDBC -related class libraries: First, you need to import related JDBC class libraries in the Java application.These class libraries are usually provided as jar packages and can be downloaded on the official website of Derby. import java.sql.*; 2. Load the driver: Before using Derby, you need to load the Derby driver through the Java's reflection mechanism.You can use the `Class.Forname () method to load the Derby driver. Class.forName("org.apache.derby.jdbc.EmbeddedDriver"); 3. Establish a database connection: Use JDBC's `DriverManager.getConnection ()` method to establish a connection with the Derby database.The URL of the database and other connection parameters specifies in the connection strings, such as the username and password. String dbUrl = "jdbc:derby:myDatabase;create=true"; Connection conn = DriverManager.getConnection(dbUrl); 4. Execute SQL statement: Once you establish a connection with the database, you can use the `statement` or` preparedatement` object to execute the SQL statement. Statement stmt = conn.createStatement(); ResultSet rs = stmt.executeQuery("SELECT * FROM myTable"); while (rs.next()) { // Process query results } 5. Close connection: After using the database, you must clearly close the connection to release related resources. rs.close(); stmt.close(); conn.close(); In summary, the application principle of the Apache Derby database engine and the embedded JDBC driver is achieved by loading the Derby driver in the Java application and the establishment of the connection with the Derby database.Through the embedded method, you can embed and manage the Derby database directly in the application to provide an efficient, lightweight database solution. The above is an example of a simple derby application. In actual use, it can also include creating tables, insert data, update data and other operations, and more complex functions such as transaction processing.I hope this article can help you understand the application principle of the Apache Derby database engine and the embedded JDBC driver in the Java class library.