黑马学习MyBatis 用MyBatis对表进行条件查询 模糊查询 动态sql

 1 package cn.itcast.domain;
 2 
 3 /*
 4 CREATE TABLE `message` (
 5   `id` int(11) NOT NULL,
 6   `command` varchar(16) DEFAULT NULL,
 7   `description` varchar(30) DEFAULT NULL,
 8   `content` varchar(2048) DEFAULT NULL,
 9   PRIMARY KEY (`id`)
10 ) ENGINE=InnoDB DEFAULT CHARSET=utf8;
11  */
12 public class Message {
13     private int id;
14     private String command;
15     private String description;
16     private String content;
17 
18     public Message(){}
19 
20     public int getId() {
21         return id;
22     }
23 
24     public void setId(int id) {
25         this.id = id;
26     }
27 
28     public String getCommand() {
29         return command;
30     }
31 
32     public void setCommand(String command) {
33         this.command = command;
34     }
35 
36     public String getDescription() {
37         return description;
38     }
39 
40     public void setDescription(String description) {
41         this.description = description;
42     }
43 
44     public String getContent() {
45         return content;
46     }
47 
48     public void setContent(String content) {
49         this.content = content;
50     }
51 
52     @Override
53     public String toString() {
54         return "Message{" +
55                 "id=" + id +
56                 ", command='" + command + '\'' +
57                 ", description='" + description + '\'' +
58                 ", content='" + content + '\'' +
59                 '}';
60     }
61 }

Message

 1 package cn.itcast.dao;
 2 
 3 import cn.itcast.domain.Message;
 4 
 5 import java.util.List;
 6 
 7 public interface MessageDao {
 8 
 9     Message findById(int id);
10 
11     //mybatis只支持单个参数，如果有多个参数将它们封装为对象
12 //    List<Message> queryMessageList(String command, String description);
13 
14     List<Message> queryMessageList(Message condition);
15 }

MessageDao

 1 package cn.itcast.mapper;
 2 
 3 import cn.itcast.domain.Message;
 4 import org.apache.ibatis.io.Resources;
 5 import org.apache.ibatis.session.SqlSession;
 6 import org.apache.ibatis.session.SqlSessionFactory;
 7 import org.apache.ibatis.session.SqlSessionFactoryBuilder;
 8 import org.junit.Before;
 9 import org.junit.Test;
10 
11 import java.io.IOException;
12 import java.io.Reader;
13 import java.util.List;
14 
15 public class MessageMapperTest {
16     SqlSessionFactory sqlSessionFactory;
17 
18     @Before
19     public void init() throws IOException {
20         //加载配置
21         Reader reader = Resources.getResourceAsReader("mybatis-config.xml");
22         //构建工厂
23         sqlSessionFactory = new SqlSessionFactoryBuilder().build(reader);
24     }
25 
26     @Test
27     public void testFindById() throws IOException {
28         SqlSession sqlSession = sqlSessionFactory.openSession(true);
29         Message message = sqlSession.selectOne("cn.itcast.mapper.MessageMapper.findById", 2);
30         System.out.println(message);
31     }
32 
33 
34     @Test
35     public void testQueryMessageList(){
36         //准备条件
37         /*Message message = new Message();
38         message.setCommand("百");
39         message.setDescription("百");*/
40 
41         String command = "百";
42         String description = "百";
43         Message message = new Message();
44         message.setCommand("%" + command + "%");
45         message.setDescription("%" + description + "%");
46 
47         SqlSession sqlSession = sqlSessionFactory.openSession(true);
48         List<Message> messageList = sqlSession.selectList("cn.itcast.mapper.MessageMapper.queryMessageList", message);
49         System.out.println(messageList);
50     }
51 
52 }

MessageMapperTest

 1 <?xml version="1.0" encoding="UTF-8"?>
 2 <!DOCTYPE configuration
 3         PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
 4         "http://mybatis.org/dtd/mybatis-3-config.dtd">
 5 <configuration>
 6 
 7     <typeAliases>
 8         <typeAlias type="cn.itcast.domain.Message" alias="Message"></typeAlias>
 9     </typeAliases>
10 
11     <environments default="development">
12         <environment id="development">
13             <transactionManager type="JDBC"></transactionManager>
14             <dataSource type="POOLED">
15                 <property name="driver" value="com.mysql.jdbc.Driver"></property>
16                 <property name="url" value="jdbc:mysql://localhost:3307/micro_message"></property>
17                 <property name="username" value="root"></property>
18                 <property name="password" value="root"></property>
19             </dataSource>
20         </environment>
21     </environments>
22 
23     <mappers>
24         <mapper resource="cn/itcast/mapper/MessageMapper.xml"></mapper>
25     </mappers>
26 
27 </configuration>

mybatis-config.xml

 1 <?xml version="1.0" encoding="UTF-8"?>
 2 <!DOCTYPE mapper
 3         PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
 4         "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
 5 <mapper namespace="cn.itcast.mapper.MessageMapper">
 6 
 7     <select id="findById" resultType="Message">
 8         select * from message where id=#{id}
 9     </select>
10 
11     <!--<select id="queryMessageList" parameterType="Message" resultType="Message">
12         select * from message
13         <where>
14             <if test="command != null">
15                 and command like "%"#{command}"%"
16             </if>
17             <if test="description != null">
18                 and description like "%"#{description}"%"
19             </if>
20         </where>
21     </select>-->
22 
23     <select id="queryMessageList" parameterType="Message" resultType="Message">
24         select * from message
25         <where>
26             <if test="command != null">
27                 and command like #{command}
28             </if>
29             <if test="description != null">
30                 and description like #{description}
31             </if>
32         </where>
33     </select>
34 
35 </mapper>

MessageMapper.xml

jdbc.driver=com.mysql.jdbc.Driver
jdbc.url=jdbc:mysql://localhost:3307/micro_message
jdbc.username=root
jdbc.password=root

jdbc.properties

# priority  :debug<info<warn<error
#you cannot specify every priority with different file for log4j
log4j.rootLogger=debug,xx

#console
log4j.appender.xx=org.apache.log4j.ConsoleAppender 
log4j.appender.xx.layout=org.apache.log4j.PatternLayout 
log4j.appender.xx.layout.ConversionPattern= [%d{yyyy-MM-dd HH:mm:ss a}]:%p %l%m%n

log4j.properties