今天完成的事情：（一定要写非常细致的内容，比如说学会了盒子模型，了解了Margin）

<?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="org.example.mapper.WorkMapper">

    <select id="selectByIds" resultType="org.example.model.Work">
        SELECT * FROM works WHERE id IN
        <foreach collection="ids" item="id" open="(" separator="," close=")">
            #{id}
        </foreach>
    </select>
    <insert id="insert" useGeneratedKeys="true" keyProperty="id">
        INSERT INTO works
        (pid, level, name, state, create_at, update_at, author, sort
        <if test="level == 2">, introduce, image, url, picture, article</if>)
        VALUES
        (#{pid}, #{level}, #{name}, #{state}, #{createAt}, #{updateAt}, #{author}, #{sort}
        <if test="level == 2">, #{introduce}, #{image}, #{url}, #{picture}, #{article}</if>)
    </insert>
    <update id="batchUpdateSort">
        UPDATE works
        SET sort = CASE id
        <foreach collection="works" item="work">
            WHEN #{work.id} THEN #{work.sort}
        </foreach>
        END
        WHERE id IN
        <foreach collection="works" item="work" open="(" separator="," close=")">
            #{work.id}
        </foreach>
    </update>
    <update id="update" parameterType="Work">
        UPDATE works SET
        pid = #{pid},
        level = #{level},
        name = #{name},
        state = #{state},
        update_at = #{updateAt},
        author = #{author},
        sort = #{sort}
        <if test="level == 2">,
            introduce = #{introduce},
            image = #{image},
            url = #{url},
            picture = #{picture}
            article = #{article}
        </if>
        WHERE id = #{id}
    </update>

    <select id="selectByCondition" resultType="Work" parameterType="java.lang.String">
        SELECT * FROM works
        WHERE 1=1
        <if test="name != null">
            AND name = #{name}
        </if>
        <if test="state != null">
            AND state = #{state}
        </if>
        <if test="pid != null">
            AND pid = #{pid}
        </if>
    </select>

    <select id="selectById" resultType="Work">
        SELECT * FROM works WHERE id = #{id}
    </select>

    <select id="selectByLevel" resultType="Work">
        SELECT
        id, pid, level, name, state,
        create_at, update_at, author, sort,
        <if test="level == 2">
            introduce, image, url, picture, article
        </if>
        <if test="level != 2">
            null as introduce, null as image, null as url, null as picture, null as article
        </if>
        FROM works
        WHERE level = #{level}
        ORDER BY sort
    </select>

    <delete id="deleteById">
        DELETE FROM works WHERE id = #{id}
    </delete>
</mapper>

明天计划的事情：（一定要写非常细致的内容）
遇到的问题：（遇到什么困难，怎么解决的）
收获：（通过今天的学习，学到了什么知识）