Mybatis简单架构之动态SQL语句

dao层

package com.qcby.dao;

import com.qcby.entity.Person;
import com.qcby.entity.User;
import org.apache.ibatis.annotations.Param;

import java.util.List;

public interface PersonDao {
    List<Person> findPerson(Person person);
    int update(Person person);
    List<Person> selectPersonByChoose(Person person);
    List<Person> selectPersonByNameAndSex(Person person);
    int trimUpdate(Person person);
    int deleteMoreByArray(@Param("ids") Integer[] ids);
    int insertMoreByList(@Param("persons") List<Person> persons);
}

实体层

package com.qcby.entity;

public class Person {
    private Integer id;
    private String name;
    private String sex;
    private Integer age;

    public Person() {
    }

    public Person(String name, String sex, Integer age) {
        this.name = name;
        this.sex = sex;
        this.age = age;
    }

    @Override
    public String toString() {
        return "Person{" +
                "id=" + id +
                ", name='" + name + '\'' +
                ", sex='" + sex + '\'' +
                ", age=" + age +
                '}';
    }

    public Integer getId() {
        return id;
    }

    public void setId(Integer id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getSex() {
        return sex;
    }

    public void setSex(String sex) {
        this.sex = sex;
    }

    public Integer getAge() {
        return age;
    }

    public void setAge(Integer age) {
        this.age = age;
    }
}

sqlmapperconfig

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE configuration
        PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration>
    <settings>
        <!--设置Mybatis输出日志-->
        <!--logImpl: 表示对日志的控制-->
        <!--STDOUT_LOGGING: 将日志输出到控制台上-->
        <setting name="logImpl" value="STDOUT_LOGGING"/>
    </settings>
    <environments default="mysql">
        <environment id="mysql">
            <!--配置事务的类型，使用本地事务策略-->
            <transactionManager type="JDBC"></transactionManager>
            <!--是否使用连接池 POOLED表示使用链接池，UNPOOLED表示不使用连接池-->
            <dataSource type="POOLED">
                <property name="driver" value="com.mysql.jdbc.Driver"/>
                <property name="url" value="jdbc:mysql://localhost:3306/mybatis_demo"/>
                <property name="username" value="root"/>
                <property name="password" value="123456"/>
            </dataSource>
        </environment>
    </environments>
    <mappers>
        <mapper resource="mapper/PersonMapper.xml"></mapper>  
    </mappers>
</configuration>

mapper

<?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.qcby.dao.PersonDao">
    <!--where if-->
    <select id="findPerson" resultType="com.qcby.entity.Person" parameterType="com.qcby.entity.Person">
        select * from person
        <where>
            <if test="name != null and name != ''">
                name = #{name}
            </if>
            <if test="sex != null">
                and sex = #{sex}
            </if>
            <if test="age != null and age != ''">
                and age = #{age}
            </if>
        </where>
    </select>

    <update id="update" parameterType="com.qcby.entity.Person" >
        update person
        <set>
            <if test="name != null and name != ''">
                name = #{name}
            </if>
            <if test="sex != null">
                and sex = #{sex}
            </if>
            <if test="age != null and age != ''">
                and age = #{age}
            </if>
        </set>
        where id = #{id}
    </update>

    <select id="selectPersonByChoose" resultType="com.qcby.entity.Person"
            parameterType="com.qcby.entity.Person">
        select * from person
        <where>
            <choose>
                <when test="name != null and name != ''">
                    name = #{name}
                </when>
                <when test="sex != null">
                    and sex = #{sex}
                </when>
                <otherwise>
                    and id=#{id}
                </otherwise>
            </choose>
        </where>
    </select>


    <select id="selectPersonByNameAndSex" parameterType="com.qcby.entity.Person"
            resultType="com.qcby.entity.Person">
        select * from person
        <trim prefix="where" prefixOverrides="and | or">
            <if test="name != null and name != ''">
                name = #{name}
            </if>
            <if test="sex != null">
                and sex = #{sex}
            </if>
            <if test="age != null and age != ''">
                and age = #{age}
            </if>
        </trim>
    </select>

    <update id="trimUpdate" parameterType="com.qcby.entity.Person">
        update person
        <trim prefix="set" suffixOverrides=",">
            <if test="name != null and name != ''">
                name = #{name},
            </if>
            <if test="sex != null">
                sex = #{sex},
            </if>
            <if test="age != null and age!=''">
                age = #{age},
            </if>
        </trim>
        where id = #{id}
    </update>

    <!--delete from person where id in (1,2,3,4,5); -->
    <delete id="deleteMoreByArray">
        delete from person where id in
        <foreach collection="ids" item="id" separator="," open="(" close=")">
            #{id}
        </foreach>
    </delete>
    <!-- collection:当前要循环的数组或者集合   -->
    <!--  item: 我们指定要循环的数组的每一个元素  -->
    <!-- separator:每一个元素应该用什么来做分割   -->
    <!-- open:当前循环是以什么开始   -->
    <!-- close:当前循环是以什么结束   -->

    <!--insert into 表名 （字段） values (值),(值)-->
    <insert id="insertMoreByList" >
        insert into user(name,sex,age) values
        <foreach collection="persons" item="person" separator=",">
            (#{person.name},#{person.sex},#{person.age})
        </foreach>
    </insert>
</mapper>

test

import com.qcby.dao.PersonDao;
import com.qcby.dao.UserDao;
import com.qcby.entity.Person;
import com.qcby.entity.User;
import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;
import org.junit.After;
import org.junit.Before;
import org.junit.Test;

import java.io.IOException;
import java.io.InputStream;
import java.util.Date;
import java.util.Arrays;
import java.util.List;

public class PersonTest {
    private InputStream in = null;
    private SqlSession session = null;
    private PersonDao mapper = null;

    @Before  //前置通知, 在方法执行之前执行
    public void init() throws IOException {
        //加载主配置文件，目的是为了构建SqlSessionFactory对象
        in = Resources.getResourceAsStream("SqlMapConfig.xml");
        //创建SqlSessionFactory对象
        SqlSessionFactory factory = new SqlSessionFactoryBuilder().build(in);
        //通过SqlSessionFactory工厂对象创建SqlSesssion对象
        session = factory.openSession();
        //通过Session创建UserDao接口代理对象
        mapper = session.getMapper(PersonDao.class);
    }

    @After  //@After: 后置通知, 在方法执行之后执行 。
    public void destory() throws IOException {
        //释放资源
        session.close();
        in.close();
    }

    @Test
    public void findPerson(){
        Person person = new Person();
        //user.setUsername("熊大");
        person.setAge(22);
        person.setSex("男");
        List<Person> persons = mapper.findPerson(person);
        for (Person person1: persons) {
            System.out.println(person1.toString());
        }
    }

    @Test
    public void insert(){
        Person person = new Person();
        person.setName("sssssss");
        person.setId(1);
        mapper.update(person);
        session.commit();
    }

    @Test
    public void selectPersonByChoose(){
        Person person1 = new Person();
        person1.setId(1);
        //user1.setUsername("admin");
        List<Person> persons = mapper.selectPersonByChoose(person1);
        for (Person person : persons) {
            System.out.println(person.toString());
        }
    }

    @Test
    public void selectUserByUsernameAndSex(){
        Person person = new Person();
        person.setName("熊大");
        // user.setAddress("上海");
        person.setAge(123);
        List<Person> persons = mapper.selectPersonByNameAndSex(person);
        for (Person person1: persons) {
            System.out.println(person1.toString());
        }
    }

    @Test
    public void trimUpdate(){
        Person person = new Person();
        person.setName("sssssss");
        person.setSex("男");
        mapper.trimUpdate(person);
        session.commit();
    }

    @Test
    public void deleteMoreByArray(){
        Integer[] integer = new Integer[]{8,9,10,11};
        mapper.deleteMoreByArray(integer);
        session.commit();
    }

    @Test
    public void insertMoreByList(){
        Person person1 = new Person("小赵","男",55);
        Person person2 = new Person("小张","男",45);
        Person person3 = new Person("小李","男",30);
        List<Person> Persons = Arrays.asList(person1,person2,person3);
        mapper.insertMoreByList(Persons);
        session.commit();
    }
}