<!--springboot的mybatis >
<dependency>    
		<groupId>org.mybatis.spring.boot</groupId>    
		<artifactId>mybatis-spring-boot-starter</artifactId>   
		<version>3.0.3</version>
</dependency>
<!-- MySQL 連接器 -->
<dependency>
    <groupId>mysql</groupId>
    <artifactId>mysql-connector-java</artifactId>
    <version>8.0.23</version>
</dependency>

<?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>
    <!-- mybatis環(huán)境 -->
    <environments default="mysql">
        <environment id="mysql">
            <!-- 配置事務(wù)的類(lèi)型 -->
            <transactionManager type="JDBC"></transactionManager>
            <!-- 配置數(shù)據(jù)源（連接池） -->
            <dataSource type="POOLED">
                <property name="driver" value="com.mysql.cj.jdbc.Driver"/>
                <property name="url" value="jdbc:mysql://localhost:3306/數(shù)據(jù)庫(kù)名稱(chēng)?userSSL=false&amp;serverTimezone=Asia/Shanghai"/>
                <property name="username" value="帳號(hào)"/>
                <property name="password" value="密碼"/>
            </dataSource>
        </environment>
    </environments>
    <!-- mybatis映射配置位置 -->
    <!-- 按模塊映射不同的配置文件，讓配置文件看起來(lái)更簡(jiǎn)潔 -->
    <mappers>
        <mapper resource="映射配置文件全路徑"></mapper>
    </mappers>
</configuration>

mybatis:
  # mapper配置文件
  mapper-locations: classpath:mapper/*.xml
  # resultType別名，沒(méi)有這個(gè)配置resultType包名要寫(xiě)全，配置后只要寫(xiě)類(lèi)名
  type-aliases-package: com.mashang.xiaomistore.domain
  configuration:
    #下劃線(xiàn)自動(dòng)轉(zhuǎn)駝峰
    map-underscore-to-camel-case: true

<?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.company.mapper.StudentMapper">
    <select id="queryAll" resultType="com.company.entity.Student">
        SELECT * FROM student
    </select>
</mapper>

public interface StudentMapper {
    List<Student> queryAll();
}

<!-- https://mvnrepository.com/artifact/org.springframework.boot/spring-boot-starter-log4j2 -->
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-log4j2</artifactId>
    <version>3.4.3</version>
</dependency>

mybatis:
  configuration:
    log-impl: org.apache.ibatis.logging.log4j.Log4jImpl

### 設(shè)置###
log4j.rootLogger = debug,stdout,D,E
### 輸出信息到控制抬 ###
log4j.appender.stdout = org.apache.log4j.ConsoleAppender
log4j.appender.stdout.Target = System.out
log4j.appender.stdout.layout = org.apache.log4j.PatternLayout
log4j.appender.stdout.layout.ConversionPattern = [%-5p] %d{yyyy-MM-dd HH:mm:ss,SSS} method:%l%n%m%n
### 輸出DEBUG 級(jí)別以上的日志到=D://logs/error.log ###
log4j.appender.D = org.apache.log4j.DailyRollingFileAppender
log4j.appender.D.File = D://logs/log.log
log4j.appender.D.Append = true
log4j.appender.D.Threshold = DEBUG 
log4j.appender.D.layout = org.apache.log4j.PatternLayout
log4j.appender.D.layout.ConversionPattern = %-d{yyyy-MM-dd HH:mm:ss}  [ %t:%r ] - [ %p ]  %m%n
### 輸出ERROR 級(jí)別以上的日志到=D://logs/error.log ###
log4j.appender.E = org.apache.log4j.DailyRollingFileAppender
log4j.appender.E.File =D://logs/error.log 
log4j.appender.E.Append = true
log4j.appender.E.Threshold = ERROR 
log4j.appender.E.layout = org.apache.log4j.PatternLayout
log4j.appender.E.layout.ConversionPattern = %-d{yyyy-MM-dd HH:mm:ss}  [ %t:%r ] - [ %p ]  %m%n

<?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.example.mapper.UserMapper">
    <!-- CRUD 配置 -->
</mapper>

<select id ="getUserById" resultType="com.company.domain.entity.User">
		SELECT * FORM user 
</select>

<select id="getUserByNameAndAge" resultType="User">
    SELECT * FROM user 
    WHERE name = #{name} AND age = #{age}
</select>

<select>
        SELECT *
        FROM user
        WHERE name LIKE CONCAT('%', #{name}, '%')
</select>

    <insert id="insertUser" parameterType="User">
        INSERT INTO user(name, age)
        VALUES (#{name}, #{age})
    </insert>

<insert id="insertUser" useGeneratedKeys="true" keyProperty="id">
    INSERT INTO user (name, age) 
    VALUES (#{name}, #{age})
</insert>

 <update id="updateUser" parameterType="User">
        UPDATE user
        SET name=#{name},
            age =#{age}
        WHERE id = #{id}
    </update>

    <delete id="deleteUserById" parameterType="Integer">
        DELETE
        FROM user
        WHERE id = #{id}
    </delete>

<select id="getUserByNameAndAge" resultType="User">
    SELECT * FROM user 
    WHERE name = #{name} AND age = #{age}
</select>

    User getUserByNameAndAge(
            @Param("name") String name,
            @Param("age") Integer age);

<insert id="insertUser" parameterType="User">
    INSERT INTO user (name, age) 
    VALUES (#{name}, #{age})
</insert>

void insertUser(User user);

<select id="getUserByMap" resultType="User">
    SELECT * FROM user 
    WHERE name = #{name} AND age = #{age}
</select>

User getUserByMap(Map<String, Object> params);

<select id="getUsersByIds" resultType="User">
    SELECT * FROM user 
    WHERE id IN
    <foreach collection="ids" item="id" open="(" separator="," close=")">
        #{id}
    </foreach>
</select>

List<User> getUsersByIds(@Param("ids") List<Integer> ids);

<select id="getUserByCondition" resultType="User">
    SELECT * FROM user
    <where>
        <if test="name != null and name != ''">
            AND name LIKE CONCAT('%', #{name}, '%')
        </if>
        <if test="age != null">
            AND age = #{age}
        </if>
    </where>
</select>

<insert id="insertUserSelective" parameterType="User">
    INSERT INTO user
    <trim prefix="(" suffix=")" suffixOverrides=",">
        <if test="name != null">name,</if>
        <if test="age != null">age,</if>
        <if test="email != null">email,</if>
    </trim>
    VALUES
    <trim prefix="(" suffix=")" suffixOverrides=",">
        <if test="name != null">#{name},</if>
        <if test="age != null">#{age},</if>
        <if test="email != null">#{email},</if>
    </trim>
</insert>

<update id="updateUserDynamic" parameterType="User">
    UPDATE user
    <set>
        <if test="name != null">name = #{name},</if>
        <if test="age != null">age = #{age},</if>
        <if test="email != null">email = #{email},</if>
    </set>
    WHERE id = #{id}
</update>

<select id="getUsersByIds" resultType="User">
    SELECT * FROM user
    <where>
        <if test="ids != null">
            AND id IN
            <foreach collection="ids" item="id" open="(" separator="," close=")">
                #{id}
            </foreach>
        </if>
    </where>
</select>

SELECT id, name, age FROM user WHERE id = #{id}

mybatis:
    map-underscore-to-camel-case: true

public class User {
    private Integer id;
    private String name;
    private Integer age;
}
public class UserDetail {
    private Integer detailId;
    private String address;
    private String phone;
}
public class UserVo {
    private Integer id;
    private String name;
    private Integer age;
    private UserDetail userDetail;  // 一對(duì)一關(guān)系：一個(gè)用戶(hù)對(duì)應(yīng)一份詳細(xì)信息 
}

<resultMap id="userVoMap" type="com.example.UserVo">
    <id property="id" column="id"/>
    <result property="name" column="name"/>
    <result property="age" column="age"/>
    <!-- 一對(duì)一映射 -->
    <association property="userDetail" javaType="com.example.UserDetail">
        <id property="detailId" column="detail_id"/>
        <result property="address" column="address"/>
        <result property="phone" column="phone"/>
    </association>
</resultMap>
<select id="getUserVoById" resultMap="userVoMap" parameterType="int">
    SELECT u.id, u.name, u.age, ud.detail_id, ud.address, ud.phone
    FROM user u
    LEFT JOIN user_detail ud ON u.id = ud.user_id
    WHERE u.id = #{id}
</select>

public class Teacher {
    private Integer id;
    private String teacherName;
    private Integer age;
    private List<Student> students; // 一對(duì)多關(guān)系：一個(gè)老師對(duì)應(yīng)多個(gè)學(xué)生
}
public class Student {
    private Integer id;
    private String name;
    private Integer age;
}

<resultMap id="teacherMap" type="com.example.Teacher">
    <id property="id" column="teacher_id"/>
    <result property="teacherName" column="teacher_name"/>
    <result property="age" column="teacher_age"/>
    <!-- 一對(duì)多映射 -->
    <collection property="students" ofType="com.example.Student">
        <id property="id" column="student_id"/>
        <result property="name" column="student_name"/>
        <result property="age" column="student_age"/>
    </collection>
</resultMap>
<select id="getTeacherWithStudents" resultMap="teacherMap" parameterType="int">
    SELECT t.id as teacher_id, t.teacher_name, t.age as teacher_age,
           s.id as student_id, s.name as student_name, s.age as student_age
    FROM teacher t
    LEFT JOIN student s ON t.id = s.teacher_id
    WHERE t.id = #{id}
</select>