mybatis-plus 标签使用示例

mybatis-plus是MyBatis的增强工具，在标签使用上与MyBatis相似。以下是mybatis-plus中常用标签的使用示例：

1. insert标签

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

2. update标签

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

3. delete标签

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

4. select标签

<select id="getUserById" parameterType="Long" resultType="User">
    SELECT id, name, age, email FROM user WHERE id=#{id}
</select>

5. resultMap标签

<resultMap id="userMap" type="User">
    <id property="id" column="id"/>
    <result property="name" column="name"/>
    <result property="age" column="age"/>
    <result property="email" column="email"/>
</resultMap>

6. association标签

<resultMap id="userMapWithDepartment" type="User">
    <id property="id" column="id"/>
    <result property="name" column="name"/>
    <result property="age" column="age"/>
    <result property="email" column="email"/>
    <association property="department" javaType="Department" column="department_id" select="getDepartmentById"/>
</resultMap>

<select id="getUserWithDepartmentById" parameterType="Long" resultMap="userMapWithDepartment">
    SELECT u.id, u.name, u.age, u.email, u.department_id FROM user u LEFT JOIN department d ON u.department_id=d.id WHERE u.id=#{id}
</select>

<select id="getDepartmentById" parameterType="Long" resultType="Department">
    SELECT id, name FROM department WHERE id=#{id}
</select>

以上是mybatis-plus标签的使用示例，希望对你有所帮助。