gold-java/src/main/resources/mapper/RateMapper.xml

<?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.demo.mapper.coin.RateMapper">
    <select id="selectAll" resultType="com.example.demo.domain.vo.coin.RateDetail">
        SELECT
            r.id,r.rate_name rateName,r.num,r.admin_id adminId,r.create_time createTime,r.update_time updateTime
        FROM rate r
    </select>

    <select id="selectById" resultType="com.example.demo.domain.entity.Rate">
        SELECT * FROM rate WHERE id= #{id}
    </select>
    <select id="listRateName" resultType="com.example.demo.domain.entity.Rate">
        SELECT
           id , rate_name rateName
        FROM rate
    </select>

    <select id="getIdByName" resultType="java.lang.Integer">
        SELECT id FROM rate WHERE rate_name = #{rateName}
    </select>

    <update id="update">
        UPDATE
            rate
       <set>
            <if test="num!=null">
                num= #{num},
            </if>
            <if test="rateName!=null and rateName.length>0">
                rate_name= #{rateName},
            </if>
            <if test="adminId!=null">
                admin_id= #{adminId},
            </if>
        </set>
        WHERE
            id=#{id}
    </update>


    <insert id="add">
        INSERT INTO rate
        (rate_name, num, admin_id, create_time)
        VALUES
        (#{rateName}, #{num}, #{adminId}, #{createTime})
        <selectKey keyProperty="id" resultType="java.lang.Integer" order="AFTER">
            SELECT LAST_INSERT_ID()
        </selectKey>
    </insert>

</mapper>