該獲取主鍵並不是絕對的，也和具體的資料庫實現的驅動有關。

package cn.itcast.jdbc;

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;

import org.junit.Test;

/**
 * 測試JDBC中的幾個其他API
 */
public class OtherApi {

	/**
	 * 測試create方法
	 * @throws SQLException
	 */
	@Test
	public void testCreate() throws SQLException {
		System.out.println(create());
	}
	
	/**
	 * 測試從資料庫讀取資料
	 * @throws SQLException
	 * @throws InterruptedException
	 */
	@Test
	public void testRead() throws SQLException, InterruptedException {
		read();
	}
	
	/**
	 * 讀取資料庫中的資料
	 * @throws SQLException
	 * @throws InterruptedException
	 */
	static void read() throws SQLException, InterruptedException {
		Connection conn = null;
		Statement st = null;
		ResultSet rs = null;
		
		try {
			//建立連線
			conn = JdbcUtils.getConnection();
			//建立語句
			st = conn.createStatement(ResultSet.TYPE_SCROLL_SENSITIVE, 
					ResultSet.CONCUR_UPDATABLE);
 

			//執行語句
			rs = st.executeQuery("select id, name, money, birthday  from user where id < 5");
			
			//處理結果
			while(rs.next()) {
				int id = rs.getInt("id");
				System.out.println("show"  + id + "...");
				Thread.sleep(10000);
				System.out.println(id +"\t" + rs.getObject("name") + "\t"
						+ rs.getObject("birthday") + "\t"
						+ rs.getObject("money"));
			}
		} finally {
			JdbcUtils.free(rs, st, conn);
		}
	}
	
	/**
	 * 向資料庫中插入語句
	 * @return
	 * @throws SQLException
	 */
	static int create() throws SQLException {
		Connection conn = null;
		PreparedStatement ps = null;
		ResultSet rs = null;
		
		try {
			//建立連線
			conn = JdbcUtils.getConnection();
			//建立語句
			String sql = "insert into user(name,birthday, money) values ('name2 gk', '1987-01-01', 400) ";
			//通過傳入第二個引數,就會產生主鍵返回給我們
			ps = conn.prepareStatement(sql, Statement.RETURN_GENERATED_KEYS);
 

			ps.executeUpdate();
			
			//返回的結果集中包含主鍵,注意：主鍵還可以是UUID,
			//複合主鍵等,所以這裡不是直接返回一個整型
			rs = ps.getGeneratedKeys();
			int id = 0;
			if(rs.next()) {
				id = rs.getInt(1);
			}
			return id;
		} finally{
			JdbcUtils.free(rs, ps, conn);
		}
	}
	
}