六、Mybatis动态SQL和模糊查询

6.1准备数据表

create table d_user(
id int primary key auto_increment,
name varchar(10),
age int(3)
);
insert into d_user(name,age) values('Tom',12);
insert into d_user(name,age) values('Bob',13);

6.2ConditionUser(查询条件实体类)

package com.entity;

public class ConditionUser {

private String name;
private int minAge;
private int maxAge;
public ConditionUser() {
super();
}
public ConditionUser(String name, int minAge, int maxAge) {
super();
this.name = name;
this.minAge = minAge;
this.maxAge = maxAge;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public int getMinAge() {
return minAge;
}
public void setMinAge(int minAge) {
this.minAge = minAge;
}
public int getMaxAge() {
return maxAge;
}
public void setMaxAge(int maxAge) {
this.maxAge = maxAge;
}
@Override
public String toString() {
return "ConditionUser [name=" + name + ", minAge=" + minAge
+ ", maxAge=" + maxAge + "]";
}
}

6.3User实体类

package com.entity;

public class User {

private int id;
private String name;
private int age;
public User()
{

}
public User(int id, String name, int age) {
super();
this.id = id;
this.name = name;
this.age = age;
}
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public int getAge() {
return age;
}
public void setAge(int age) {
this.age = age;
}
@Override
public String toString() {
return "User [id=" + id + ", name=" + name + ", age=" + age + "]";
}

}

6.4user2Mapper.xml映射文件

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
"http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.config.user2Mapper">
<!--
实现多条件查询用户(姓名模糊匹配, 年龄在指定的最小值到最大值之间)
-->
<select id="getUser" parameterType="com.entity.ConditionUser" resultType="com.entity.User">
select * from d_user where

<if test='name!="%null%"'>
name like #{name} and
</if>

age between #{minAge} and #{maxAge}
</select>
</mapper>

6.5测试类

package com.test;

import java.io.IOException;
import java.util.List;

import org.apache.ibatis.session.SqlSession;
import org.junit.Test;

import com.entity.ConditionUser;
import com.entity.User;
import com.util.MybatisUtil;

public class Test6 {

@Test
public void testDynamicSql() throws IOException
{
SqlSession session=MybatisUtil.getSession();
String statement="com.config.user2Mapper.getUser";

String name="o";
//name=null;
ConditionUser parameter=new ConditionUser("%"+name+"%",13,18);
List<User> list=session.selectList(statement, parameter);
session.close();
System.out.println(list);
}

}