JDBC - 导航结果集示例
以下是使用结果集教程中描述的几种导航方法的示例。
本示例代码是根据前面章节中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 Goodbye! C:\>

