mybatis存在更新不存在新增问题_Java

mybatis存在更新不存在新增

主键或者唯一索引，有相同的字段进行添加时进行其他字段更新，否则进行新增

<insert id="insertfwdcblacklist" parametertype="com.qujie.mintwo.life.fwdc.entity.fwdcblacklist">
        insert   into fwdc_blacklist
        <trim prefix="(" suffix=")" suffixoverrides=",">
            <if test="id != null">id,</if>
            <if test="shopid != null">shop_id,</if>
            <if test="shopname != null">shop_name,</if>
            <if test="sdmerid != null">sdmerid,</if>
            <if test="shieldfunction != null">shield_function,</if>
            <if test="creditcode != null">credit_code,</if>
            <if test="idcard != null">idcard,</if>
            <if test="addtime != null">add_time,</if>
            <if test="adduserid != null">add_user_id,</if>
            <if test="updatetime != null">update_time,</if>
            <if test="updateuserid != null">update_user_id,</if>
            <if test="remark != null">remark,</if>
         </trim>
        <trim prefix="values (" suffix=")" suffixoverrides=",">
            <if test="id != null">#{id},</if>
            <if test="shopid != null">#{shopid},</if>
            <if test="shopname != null">#{shopname},</if>
            <if test="sdmerid != null">#{sdmerid},</if>
            <if test="shieldfunction != null">#{shieldfunction},</if>
            <if test="creditcode != null">#{creditcode},</if>
            <if test="idcard != null">#{idcard},</if>
            <if test="addtime != null">#{addtime},</if>
            <if test="adduserid != null">#{adduserid},</if>
            <if test="updatetime != null">#{updatetime},</if>
            <if test="updateuserid != null">#{updateuserid},</if>
            <if test="remark != null">#{remark},</if>
         </trim>
        on duplicate key update
        shield_function=#{shieldfunction}
    </insert>

mybatis存在就更新,不存在就插入

条件

主键或唯一索引在现有表中已经存在

方法

on duplicate key update

<update id= "userinfo">
insert into user
(id,username,age)
values
(#{id},#{username},#{age})
on duplicate key update
username=values(username),
age=values(age)
<update>

当id在现有表中存在时，就会执行update语句

注意事项：