MyBatis实现动态语句操作

 

实体类

public class Person {
    //实体属性
    private Integer id;
    private String name;
    private Integer age;
    private String sex;
    private String birthday;
    private Double salary;
    private Timestamp createTime;
    
    //get-set方法
    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 Integer getAge() {
        return age;
    }
    public void setAge(Integer age) {
        this.age = age;
    }
    public String getSex() {
        return sex;
    }
    public void setSex(String sex) {
        this.sex = sex;
    }
    public String getBirthday() {
        return birthday;
    }
    public void setBirthday(String birthday) {
        this.birthday = birthday;
    }
    public Double getSalary() {
        return salary;
    }
    public void setSalary(Double salary) {
        this.salary = salary;
    }
    public Timestamp getCreateTime() {
        return createTime;
    }
    public void setCreateTime(Timestamp createTime) {
        this.createTime = createTime;
    }
    
    //toString方法
    @Override
    public String toString() {
        return "User [id=" + id + ", name=" + name + ", age=" + age + ", sex=" + sex + ", birthday=" + birthday
                + ", salary=" + salary + ", createTime=" + createTime + "]";
    }

}

Dao层接口

public interface PersonDao {
    
    /**
     * 查询(条件)
     */
    Collection<Person> selectPerson(Person person);
    
    /**
     * 查询所有
     */
    Collection<Person> selectAll();
    
    /**
     * 修改
     */
    boolean update(Person person);
    
    /**
     * 插入
     */
    boolean insertPerson(Person person);
    
    /**
     * 删除
     */
    int deleteOne(Person person);
    
    /**
     * 批量删除
     */
    int deleteMany(List<Person> personList);
    
    
}

Mapper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.test.dao.user.PersonDao">
    <!-- 增加实体 -->
    <insert id="insertPerson" useGeneratedKeys="true" keyProperty="id">
        insert into user
        <trim prefix="(" suffix=")" suffixOverrides=",">
            <if test="name !=null">name,</if>
            <if test="age != 0">age,</if>
            <if test="sex !=null">sex</if>
        </trim>
        values
        <trim prefix="(" suffix=")" suffixOverrides=",">
            <if test="name !=null">#{name},</if>
            <if test="age != 0">#{age},</if>
            <if test="sex !=null">#{sex}</if>
        </trim>
    </insert>
    
    <!-- 查询 条件-->
    <select id="selectPerson" resultType="com.test.model.user.Person">
        select * from user 
        <where>
            <if test="id!=null">id = #{id}</if>
            <if test="id!=null">and name = #{name}</if>
            <if test="id!=null">and age = #{age}</if>
        </where>
    </select>
    
    <!-- 查询所有 -->
    <select id="selectAll" resultType="com.test.model.user.Person">
        select * from user
    </select>
    
    <!-- 更新 -->
    <update id="update">
        update user 
        <set>
            <if test="name!=null">name=#{name},</if>
            <if test="age!=null">age=#{age},</if>
            <if test="sex!=null">sex=#{sex},</if>
            <if test="birthday!=null">birthday=#{birthday},</if>
            <if test="birthday!=null">birthday=#{birthday},</if>
            <if test="salary!=null">salary=#{salary},</if>
            <if test="createTime!=null">createTime=#{createTime},</if>
        </set>
        where id = #{id}
    </update>
    
    <!-- 删除 -->
    <delete id="deleteOne">
        delete from user
        <where>
            <if test="id != null">id=#{id}</if>
            <if test="name != null">and name=#{name}</if>
            <if test="age != null">and age=#{age}</if>
        </where>
    </delete>
    
    <!-- 批量删除 -->
    <delete id="deleteMany">
        delete from user where id in
        <foreach collection="list" open="(" close=")" separator="," item="id">
            #{id}
        </foreach>
    </delete>
    
</mapper>

测试类

/**
     *插入
     */
    @Test
    public void insert() {
        //创建实体
        Person person = new Person();
        person.setName("Tom");
        person.setAge(18);
        person.setSex("男");
        person.setBirthday("2001-09-01");
        person.setSalary(12000.0);
        Date date = new Date(System.currentTimeMillis());       
        Timestamp createTime = new Timestamp(date.getTime());
        person.setCreateTime(createTime);
        System.out.println(person);
        //新增实体到数据库
        boolean create = personDao.insertPerson(person);
        System.out.println(create);
    }
    
    /**
     * 查询全部
     */
    @Test
    public void selectAll() {
        Collection<Person> selectAll = personDao.selectAll();
        for (Person person : selectAll) {
            System.out.println(person);
        }
    }
    
    /**
     * 条件查询
     */
    @Test
    public void select() {
        Person person = new Person();
//        person.setId(4);
        person.setName("Tom");
        person.setAge(18);
        Collection<Person> selectPerson = personDao.selectPerson(person);
        for (Person person2 : selectPerson) {
            System.out.println(person2);
        }
    }
    
    /**
     * 根据id查询用户
     */
    @Test
    public void update() {
        //创建实体
        Person person = new Person();
        person.setId(4);
        person.setName("Rose");
        person.setAge(18);
        boolean update = personDao.update(person);
        System.out.println(update);
    }
    
    
    /**
     * 根据id查询用户
     */
    @Test
    public void delete() {
        //创建实体
        Person person = new Person();
        person.setId(4);
        person.setName("Rose");
        person.setAge(18);        
        int b = personDao.deleteOne(person);
        System.out.println(b);
    }

后面要整理。。。。