JDBC - 查看结果集示例
以下是示例,它使用了结果集章节中描述的少数 getInt 和 getString 方法。 此示例与导航结果集部分中解释的前一个示例非常相似。
此示例代码是根据前面章节中完成的环境和数据库设置编写的。
将以下示例复制粘贴到JDBCExample.java中,编译运行如下 −
import java.sql.Connection; import java.sql.DriverManager; import java.sql.ResultSet; import java.sql.SQLException; import java.sql.Statement; public class JDBCExample { static final String DB_URL = "jdbc:mysql://localhost/TUTORIALSPOINT"; static final String USER = "guest"; static final String PASS = "guest123"; static final String QUERY = "SELECT id, first, last, age FROM Employees"; public static void main(String[] args) { // Open a connection try(Connection conn = DriverManager.getConnection(DB_URL, USER, PASS); Statement stmt = conn.createStatement( ResultSet.TYPE_SCROLL_INSENSITIVE, ResultSet.CONCUR_READ_ONLY); ResultSet rs = stmt.executeQuery(QUERY); ) { // Move cursor to the last row. System.out.println("Moving cursor to the last..."); rs.last(); // Extract data from result set System.out.println("Displaying record..."); //Retrieve by column name int id = rs.getInt("id"); int age = rs.getInt("age"); String first = rs.getString("first"); String last = rs.getString("last"); // Display values System.out.print("ID: " + id); System.out.print(", Age: " + age); System.out.print(", First: " + first); System.out.println(", Last: " + last); // Move cursor to the first row. System.out.println("Moving cursor to the first row..."); rs.first(); // Extract data from result set System.out.println("Displaying record..."); // Retrieve by column name id = rs.getInt("id"); age = rs.getInt("age"); first = rs.getString("first"); last = rs.getString("last"); // Display values System.out.print("ID: " + id); System.out.print(", Age: " + age); System.out.print(", First: " + first); System.out.println(", Last: " + last); // Move cursor to the first row. System.out.println("Moving cursor to the next row..."); rs.next(); // Extract data from result set System.out.println("Displaying record..."); id = rs.getInt("id"); age = rs.getInt("age"); first = rs.getString("first"); last = rs.getString("last"); // Display values System.out.print("ID: " + id); System.out.print(", Age: " + age); System.out.print(", First: " + first); System.out.println(", Last: " + last); } catch (SQLException e) { e.printStackTrace(); } } }
现在让我们编译上面的例子如下 −
C:\>javac JDBCExample.java C:\>
当您运行 JDBCExample 时,它会产生以下结果 −
C:\>java JDBCExample Moving cursor to the last... Displaying record... ID: 103, Age: 30, First: Sumit, Last: Mittal Moving cursor to the first row... Displaying record... ID: 100, Age: 18, First: Zara, Last: Ali Moving cursor to the next row... Displaying record... ID: 101, Age: 25, First: Mehnaz, Last: Fatma C:\>