Apache Derby database engine and embedded JDBC driver technology principles in the Java class library
Apache Derby database engine and embedded JDBC driver technology principles analysis
Brief introduction
Apache Derby is an open source -type database engine, and it is also a embedded database in Java programming language.It is implemented with Java technology and has small storage space requirements and height scalability.This article will explore the working principles of the Apache Derby database engine and the embedded JDBC drive, as well as how to use these technologies in the Java code.
Apache Derby database engine principle
The Apache Derby database engine is based on the implementation of a relational database management system (RDBMS).It supports SQL language and provides reliable, high -performance data storage and retrieval functions.Apache Derby uses B tree index as its internal storage structure.It organizes data in an index to improve the access speed and query performance of data.In addition, Derby also adopts a log and checkpoint mechanism to ensure the security and consistency of data.
Apache Derby also supports transaction processing.When the user executes update, insertion, deletion, etc., Derby automatically starts a transaction to ensure the integrity of the data.Users can manually manage database changes by submitting or rolling transactions.
Principles of embedded JDBC driver technology
Apache Derby also provides a driver of JDBC (Java DataBase Connectivity), allowing developers to embed and use Derby databases directly in their Java programs.
The principle of embedded JDBC driver technology is to embed the Derby engine into the application, and the application directly communicates with the Derby engine without the need to connect to an independent Derby server through the network.
The following is a simple example code. Demonstrate how to use the embedded JDBC driver connection and operation Derby database in the Java program:
import java.sql.*;
public class DerbyExample {
public static void main(String[] args) {
Connection conn = null;
try {
// Set the Derby database connection URL
String dbUrl = "jdbc:derby:mydb;create=true";
// Get derby driver
Class.forName("org.apache.derby.jdbc.EmbeddedDriver");
// Create a database connection
conn = DriverManager.getConnection(dbUrl);
// Create a table
Statement statement = conn.createStatement();
String createTableSql = "CREATE TABLE my_table (id INT, name VARCHAR(50))";
statement.executeUpdate(createTableSql);
// Insert data
String insertSql = "INSERT INTO my_table (id, name) VALUES (1, 'John')";
statement.executeUpdate(insertSql);
// Query data
String selectSql = "SELECT * FROM my_table";
ResultSet resultSet = statement.executeQuery(selectSql);
// Print the query results
while (resultSet.next()) {
int id = resultSet.getInt("id");
String name = resultSet.getString("name");
System.out.println("id: " + id + ", name: " + name);
}
} catch (Exception e) {
e.printStackTrace();
} finally {
try {
// Close the database connection
if (conn != null) {
conn.close();
}
} catch (SQLException e) {
e.printStackTrace();
}
}
}
}
In the above code, first load the derby JDBC drive through the method of `class.formname ()`.Then, use the `DriverManager.getConnection () method to establish a connection with the Derby database. The" Create = TRUE "in the connection URL means that a new database is created if the database does not exist.Next, you can execute SQL statements to create tables, insert data and query data.
in conclusion
The Apache Derby database engine and embedded JDBC driver technology are important tools for Java developers to use relational databases.Using the Derby database engine can realize high -performance data storage and retrieval, and the embedded JDBC driver technology makes it possible to seamlessly embed the Derby database into the Java application.For Java developers who need to integrate databases in the application, Apache Derby is a simple, lightweight and powerful choice.
