JDBC 获取插入记录的主键值（9）

import java.sql.*;

public class JDBCTest03 {
    public static void testGetKeyValue() throws ClassNotFoundException, SQLException, SQLException {
        String sql = "INSERT INTO examstudent(type,id_card, exam_card, student_name,location,grade)"
                + "VALUES(?,?,?,?,?,?)";
        String driverClass = "com.mysql.jdbc.Driver";
        String jdbcUrl = "jdbc:mysql://localhost:3306/myemployees?useUnicode=true&useSSL=false";
        String user = "root";
        String password = "abcd123456";
        Class.forName(driverClass);
        Connection connection = DriverManager.getConnection(jdbcUrl,user,password);
        // 返回主键核心代码，preparedStatement(）重载方法
        PreparedStatement preparedStatement = connection.prepareStatement(sql, Statement.RETURN_GENERATED_KEYS);
        preparedStatement.setInt(1,5);
        preparedStatement.setString(2,"1234567890");
        preparedStatement.setString(3,"12345");
        preparedStatement.setString(4,"ee");
        preparedStatement.setString(5,"SH");
        preparedStatement.setInt(6,10);
        preparedStatement.executeUpdate();
        // 通过getGeneratedKeys()获取包含了新恒诚的主键的ResultSet对象
        // 在ResultSet中只有1列 GENERATED_KEY，用于存放新生成的主键值
        ResultSet rs = preparedStatement.getGeneratedKeys();
        if(rs.next()){
            System.out.println(rs.getObject(1));
        }
        ResultSetMetaData rsmd = rs.getMetaData();
        for(int i = 0; i < rsmd.getColumnCount();i++){
            System.out.println(rsmd.getColumnName(i + 1));
        }
        rs.close();
        preparedStatement.close();
        connection.close();
    }

    public static void main(String[] args) throws SQLException, ClassNotFoundException {
        testGetKeyValue();
    }
}