使用QueryRunner测试添加数据的操作、使用QueryRunner查询表中一条或多条记录的操作、使用QueryRunner查询表中特殊值的操作、自定义ResultSetHandler的实现类完成查询操作
package top.qaqaq.P51.dbutils;

import java.sql.Connection;
import java.sql.Date;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.List;
import java.util.Map;

import org.apache.commons.dbutils.QueryRunner;
import org.apache.commons.dbutils.ResultSetHandler;
import org.apache.commons.dbutils.handlers.BeanHandler;
import org.apache.commons.dbutils.handlers.BeanListHandler;
import org.apache.commons.dbutils.handlers.MapHandler;
import org.apache.commons.dbutils.handlers.MapListHandler;
import org.apache.commons.dbutils.handlers.ScalarHandler;
import org.junit.Test;

import top.qaqaq.P43.bean.Customer;
import top.qaqaq.P48.util.JDBCUtils;

/*
 * commons-dbutils 是 Apache 组织提供的一个开源 JDBC工具类库,封装了针对于数据库的增删改查操作
 * 
 */
public class QueryRunnerTest {
	
	//测试插入
	@Test
	public void testInsert() {
		Connection conn = null;
		try {
			QueryRunner runner = new QueryRunner();
			conn = JDBCUtils.getConnection3();
			String sql = "insert into customers(name,email,birth) values(?,?,?)";
			int insertCount = runner.update(conn, sql, "蔡徐坤", "caixukun@126.com", "1997-09-08");
			System.out.println("添加了" + insertCount + "条记录");
		} catch (SQLException e) {
			e.printStackTrace();
		} finally {
			JDBCUtils.closeResource(conn, null);
		}

	}
	
	//测试查询
	/*
	 * BeanHander:是ResultSetHandler接口的实现类,用于封装表中的一条记录
	 */
	@Test
	public void testQuery1() {
		Connection conn = null;
		try {
			QueryRunner runner = new QueryRunner();
			conn = JDBCUtils.getConnection3();
			String sql = "select id,name,email,birth from customers where id = ?";
			BeanHandler<Customer> handler = new BeanHandler<>(Customer.class);
			Customer customer = runner.query(conn, sql, handler, 25);
			System.out.println(customer);
		} catch (SQLException e) {
			e.printStackTrace();
		} finally {
			JDBCUtils.closeResource(conn, null);
		}
		
	}
	
	/*
	 * BeanListHandler:是ResultSetHandler接口的实现类,用于封装表中的多条记录构成的集合。
	 */
	@Test
	public void testQuery2() {
		Connection conn = null;
		try {
			QueryRunner runner = new QueryRunner();
			conn = JDBCUtils.getConnection3();
			String sql = "select id,name,email,birth from customers where id < ?";
			
			BeanListHandler<Customer> handler = new BeanListHandler<>(Customer.class);
			
			List<Customer> list = runner.query(conn, sql, handler, 25);
			list.forEach(System.out::println);
		} catch (SQLException e) {
			e.printStackTrace();
		} finally {
			JDBCUtils.closeResource(conn, null);
		}
		
	}
	
	/*
	 * MapHander:是ResultSetHandler接口的实现类,对应表中的一条记录。
	 * 将字段及相应字段的值作为map中的key和value
	 */
	@Test
	public void testQuery3() {
		Connection conn = null;
		try {
			QueryRunner runner = new QueryRunner();
			conn = JDBCUtils.getConnection3();
			String sql = "select id,name,email,birth from customers where id = ?";
			
			MapHandler handler = new MapHandler();
			
			Map<String,Object> map = runner.query(conn, sql, handler, 25);
			System.out.println(map);
		} catch (SQLException e) {
			e.printStackTrace();
		} finally {
			JDBCUtils.closeResource(conn, null);
		}
		
	}
	
	/*
	 * MapListHander:是ResultSetHandler接口的实现类,对应表中的多条记录。
	 * 将字段及相应字段的值作为map中的key和value。将这些map添加到List中
	 */
	@Test
	public void testQuery4() {
		Connection conn = null;
		try {
			QueryRunner runner = new QueryRunner();
			conn = JDBCUtils.getConnection3();
			String sql = "select id,name,email,birth from customers where id < ?";
			
			MapListHandler handler = new MapListHandler();
			
			List<Map<String, Object>> list = runner.query(conn, sql, handler, 25);
			list.forEach(System.out::println);
		} catch (SQLException e) {
			e.printStackTrace();
		} finally {
			JDBCUtils.closeResource(conn, null);
		}
		
	}
	
	/*
	 * ScalarHandler:用于查询特殊值
	 */
	@Test
	public void testQuery5() {
		Connection conn = null;
		try {
			QueryRunner runner = new QueryRunner();
			conn = JDBCUtils.getConnection3();
			
			String sql = "select count(*) from customers";
			
			ScalarHandler handler = new ScalarHandler();
			
			Long count = (Long) runner.query(conn, sql, handler);
			System.out.println(count);
		} catch (SQLException e) {
			e.printStackTrace();
		} finally {
			JDBCUtils.closeResource(conn, null);
		}
		
	}
	
	@Test
	public void testQuery6() {
		Connection conn = null;
		try {
			QueryRunner runner = new QueryRunner();
			conn = JDBCUtils.getConnection3();
			
			String sql = "select max(birth) from customers";
			
			ScalarHandler handler = new ScalarHandler();
			
			Date maxBirth = (Date) runner.query(conn, sql, handler);
			System.out.println(maxBirth);
		} catch (SQLException e) {
			e.printStackTrace();
		} finally {
			JDBCUtils.closeResource(conn, null);
		}
		
	}
	
	/*
	 * 自定义ResultSetHandler的实现类
	 */
	@Test
	public void testQuery7() {
		Connection conn = null;
		try {
			QueryRunner runner = new QueryRunner();
			conn = JDBCUtils.getConnection3();
			
			String sql = " select id,name,email,birth from customers where id = ?";
			ResultSetHandler<Customer> handler = new ResultSetHandler<Customer>() {

				@Override
				public Customer handle(ResultSet rs) throws SQLException {
//					System.out.println("handle");
//					return null;
					
//					return new Customer(12, "成龙", "jacky@126.com", new Date(23131414214412L));
					
					if(rs.next()) {
						int id = rs.getInt("id");
						String name = rs.getString("name");
						String email = rs.getString("email");
						Date birth = rs.getDate("birth");
						Customer customer = new Customer(id, name, email, birth);
						return customer;
					}
					
					return null;
				}
				
			};
			Customer customer = runner.query(conn, sql, handler,23);
			System.out.println(customer);
		} catch (SQLException e) {
			e.printStackTrace();
		} finally {
			JDBCUtils.closeResource(conn, null);
		}
		
	}
}
暂无评论

发送评论 编辑评论


				
|´・ω・)ノ
ヾ(≧∇≦*)ゝ
(☆ω☆)
(╯‵□′)╯︵┴─┴
 ̄﹃ ̄
(/ω\)
∠( ᐛ 」∠)_
(๑•̀ㅁ•́ฅ)
→_→
୧(๑•̀⌄•́๑)૭
٩(ˊᗜˋ*)و
(ノ°ο°)ノ
(´இ皿இ`)
⌇●﹏●⌇
(ฅ´ω`ฅ)
(╯°A°)╯︵○○○
φ( ̄∇ ̄o)
ヾ(´・ ・`。)ノ"
( ง ᵒ̌皿ᵒ̌)ง⁼³₌₃
(ó﹏ò。)
Σ(っ °Д °;)っ
( ,,´・ω・)ノ"(´っω・`。)
╮(╯▽╰)╭
o(*////▽////*)q
>﹏<
( ๑´•ω•) "(ㆆᴗㆆ)
😂
😀
😅
😊
🙂
🙃
😌
😍
😘
😜
😝
😏
😒
🙄
😳
😡
😔
😫
😱
😭
💩
👻
🙌
🖕
👍
👫
👬
👭
🌚
🌝
🙈
💊
😶
🙏
🍦
🍉
😣
Source: github.com/k4yt3x/flowerhd
颜文字
Emoji
小恐龙
花!
上一篇
下一篇