mybatis通过＜foreach＞拼接sql批量更新数据（where条件和更新对应字段都是动态变化处理的）条件和更新字段都是通过java代码传过来的

 xml代码如下：

    <select id="updateQuestionHistoryAnswer">update  et_user_question_historyset  error_book =<foreach collection="updateAll" item="item" index="index" separator=" " open="case question_id" close="end">when #{item.questionId} then #{item.errorBook}</foreach>, is_right =<foreach collection="updateAll" item="item" index="index" separator=" " open="case question_id" close="end">when #{item.questionId} then #{item.isRight}</foreach>whereuser_id =  #{userId } and  question_id in<foreach item="item" index="index" collection="updateAll" open="("  close=")" separator=",">#{item.questionId}</foreach></select>

参数配置如下：

 mapper代码

void updateQuestionHistoryAnswer(@Param("updateAll")List<QuestionHistoryAnswer> updateAll, @Param("userId")Integer userId );

实体类代码

@Data
public class QuestionHistoryAnswer {private int questionId;private boolean isRight;private int userId;private String createTime;private String updateTime;private boolean errorBook;
}