1. selectKey标签查询
DDL
CREATE TABLE `luck_reward_info` (
`id` int NOT NULL AUTO_INCREMENT COMMENT 'id',
`activity_id` varchar(20) CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci NOT NULL COMMENT '活动id',
`reward_name` varchar(255) CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci DEFAULT NULL COMMENT '奖品名',
`reward_level` int DEFAULT NULL COMMENT '奖品等级',
`num` int DEFAULT NULL COMMENT '奖品数量',
`dis_number` int DEFAULT '0' COMMENT '已发奖品数量',
`create_time` datetime DEFAULT NULL COMMENT '创建时间',
`update_time` datetime DEFAULT NULL COMMENT '修改时间',
`field` varchar(255) DEFAULT NULL COMMENT '备注',
PRIMARY KEY (`id`,`activity_id`) USING BTREE
) ENGINE=InnoDB AUTO_INCREMENT=6 DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_0900_ai_ci ROW_FORMAT=DYNAMIC COMMENT='奖品信息表';RewardInfoMapper接口
@Mapper
public interface RewardInfoMapper{
int saveOrUpdate(RewardInfo rewardInfo);
}使用selectKey
<insert id="saveOrUpdate" >
<selectKey keyProperty="count" resultType="int" order="BEFORE">
select count(*) from luck_reward_info where id = #{id}
</selectKey>
<if test="count > 0">
UPDATE luck_reward_info
<set>
<if test='activityId != null and activityId != "" '>activity_id=#{activityId},</if>
<if test='rewardName != null and rewardName != "" '>reward_name=#{rewardName},</if>
<if test='rewardLevel != null '>reward_level=#{rewardLevel},</if>
<if test='num != null '>num=#{num},</if>
<if test='disNumber != null '>dis_number=#{disNumber},</if>
update_time=now(),
<if test='field != null and field != "" '>field=#{field},</if>
</set>
WHERE id=#{id}
</if>
<if test="count==0">
INSERT INTO luck_reward_info(
id,activity_id,reward_name,reward_level,number,create_time,field
)
VALUES (
(select id from (select (ifnull(max(id), 0)) + 1 as id from luck_reward_info)t), #{activityId},#{rewardName},#{rewardLevel},#{number},now(),#{field}
)
</if>
</insert>报错：
org.mybatis.spring.MyBatisSystemException: nested exception is org.apache.ibatis.executor.ExecutorException: No setter found for the keyProperty ‘count’ in com.cmbchina.ssm.entity.RewardInfo.
原因：RewardInfo内必须有count属性，来接收count值，否则报错
优化：接口使用Map，实体类不需要再新增count字段了
//RewardInfoMapper.java
int saveOrUpdate(Map<String, Object> map);2. 主键自增或者累加的，不使用selectKey
根据id是否为空，空新增，不为空修改
<insert id="saveOrUpdate" keyProperty="id" useGeneratedKeys="true">
<if test="id == null">
INSERT INTO luck_reward_info(
id,activity_id,reward_name,reward_level,num,create_time,field
)
VALUES (
(select id from (select (ifnull(max(id), 0)) + 1 as id from luck_reward_info)t), #{activityId},#{rewardName},#{rewardLevel},#{num},now(),#{field}
)
</if>
<if test="id != null">
UPDATE luck_reward_info
<set>
<if test='activityId != null and activityId != "" '>activity_id=#{activityId},</if>
<if test='rewardName != null and rewardName != "" '>reward_name=#{rewardName},</if>
<if test='rewardLevel != null '>reward_level=#{rewardLevel},</if>
<if test='num!= null '>num=#{num},</if>
<if test='disNumber != null '>dis_number=#{disNumber},</if>
update_time=now(),
<if test='field != null and field != "" '>field=#{field},</if>
</set>
WHERE id=#{id}
</if>
</insert>3. 主键为varchar的使用ON DUPLICATE KEY UPDATE
DDL
CREATE TABLE `luck_activity_info` (
`id` varchar(20) CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci NOT NULL COMMENT 'id',
`title` varchar(255) CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci DEFAULT NULL COMMENT '标题',
`start_time` datetime DEFAULT NULL COMMENT '开始时间',
`end_time` datetime DEFAULT NULL COMMENT '结束时间',
`sap_id` varchar(255) CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci DEFAULT NULL COMMENT '操作员工编号',
`create_time` datetime DEFAULT NULL COMMENT '创建时间',
`update_time` datetime DEFAULT NULL COMMENT '修改时间',
PRIMARY KEY (`id`) USING BTREE
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_0900_ai_ci ROW_FORMAT=DYNAMIC COMMENT='抽奖活动表';条数 新增返回1，修改返回2
<insert id="saveOrUpdate">
INSERT INTO luck_activity_info(
id,title,start_time,end_time,sap_id,create_time
)
VALUES (
#{id},#{title},#{startTime},#{endTime},#{sapId},now()
)
ON DUPLICATE KEY UPDATE
<if test='title != null and title != "" '>title=#{title},</if>
<if test='startTime != null '>start_time=#{startTime},</if>
<if test='endTime != null '>end_time=#{endTime},</if>
<if test='sapId != null and sapId != "" '>sap_id=#{sapId},</if>
update_time=now()
</insert>总结
以上为个人经验，希望能给大家一个参考，也希望大家多多支持编程网。
