★ 数据库信息

✔ 数据库版本：openGauss 5.0.0
✔ 数据库端口：5432
✔ 数据库名称：db_zzt

★ Java代码

package PAC_001;import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;public class C_O {public static void main(String[] args) {// 创建数据库连接。Connection conn = GetConnection("zzt", "PASSWORD");// 执行预编译语句，查询数据SelectPreparedSQL(conn);// 关闭数据库连接。try {conn.close();System.out.println("Disconnect succeed!");} catch (SQLException e) {e.printStackTrace();}}public static Connection GetConnection(String username, String passwd) {String driver = "org.postgresql.Driver";String sourceURL = "jdbc:postgresql://1.1.1.9:5432/db_zzt";Connection conn = null;try {Class.forName(driver);} catch (Exception e) {e.printStackTrace();return null;}try {conn = DriverManager.getConnection(sourceURL, username, passwd);System.out.println("Connection succeed!");} catch (Exception e) {e.printStackTrace();return null;}return conn;};public static void SelectPreparedSQL(Connection conn) {PreparedStatement pstmt = null;try {String sql;sql = "SELECT empno,ename FROM zzt.emp";pstmt = conn.prepareStatement(sql);ResultSet rs = pstmt.executeQuery();while (rs.next()) {int id = rs.getInt("empno");String name = rs.getString("ename");System.out.print("ID: " + id);System.out.print(", NAME: " + name);System.out.print("\n");}System.out.println("Select table succeed!");rs.close();pstmt.close();} catch (SQLException e) {if (pstmt != null) {try {pstmt.close();} catch (SQLException e1) {e1.printStackTrace();}}e.printStackTrace();}}
}