springboot整合mybatis实现数据库的更新批处理方式

2023-03-12 17:34

短信预约 -IT技能 免费直播动态提醒

springboot整合mybatis实现数据库更新批处理

1.在mapper接口中编写方法


Integer batchBookCountStork(@Param("bookList") List<CartItem> bookList);

2.在mapper.xml中编写对相应的更新sql语句

<update id="batchBookCountStork" parameterType="java.util.List">
    UPDATE t_book
    <set>
        <foreach collection="bookList" item="book" index="index" open="`sales` = CASE `book_id`" close="END,">
            WHEN #{book.bookId} THEN sales+#{book.count}
        </foreach>
        <foreach collection="bookList" item="book" index="index" open="`stock` = CASE `book_id`" close="END,">
            WHEN #{book.bookId} THEN stock-#{book.count}
        </foreach>
    </set>
    <where>
        <foreach collection="bookList" item="book" index="index" open="`book_id` IN(" close=")" separator=",">
            #{book.bookId}
        </foreach>
    </where>
  </update>

3.这个配置文件的sql语句流程如下：

update t_book(表名)
set sales(这个是数据库的销量字段名) = case book_id(这个是数据库的id字段名)
    when bookid(从list集合中取出来的) then sales+(从集合中取出的数据)
    ...(这里可以一直进行拼接)
  end,
    stock(这个是数据库的库存字段名) = CASE book_id(这个是数据库的id字段名)
    when bookid(从list集合中取出来的) then stock-(从集合中取出数据)
    ...(这里可以一直进行拼接)
  end,
where `book_id`(这个是数据库的id字段名) IN(bookid(从list集合中取出来),bookid(从list集合中取出来)...)

4.这个sql语句的含义：

更新表里面的数据根据集合遍历出来的id值，设置要更新的字段名，让要更新的字段值跟这个表的主键id进行绑定，当这个主键id与list中取出来的id值一致时就让这个要更新的字段名，取then后面的值

Mybatis批量更新数据库 MybatisBatchUtils batchInsertupdate spring boot

MybatisBatchUtils

    int cnt = mybatisBatchUtils.batchUpdateOrInsert(addList, UiConfigDetailMapper.class,
                            (item, uiConfigDetailMapper) -> uiConfigDetailMapper.insertSelective(item));


package cn.XXX.dao.serivce.common;

import com.XXX.doctorusercenter.exception.BusinessException;
import lombok.extern.slf4j.Slf4j;
import org.apache.ibatis.session.ExecutorType;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.springframework.stereotype.Component;

import javax.annotation.Resource;
import java.util.List;
import java.util.function.BiFunction;


@Slf4j
@Component
public class MybatisBatchUtils {

    
    private static final int BATCH_SIZE = 1000;

    @Resource
    private SqlSessionFactory sqlSessionFactory;

    
    public <T, U, R> int batchUpdateOrInsert(List<T> data, Class<U> mapperClass, BiFunction<T, U, R> function)  {
        int i = 1;
        SqlSession batchSqlSession = sqlSessionFactory.openSession(ExecutorType.BATCH);
        try {
            U mapper = batchSqlSession.getMapper(mapperClass);
            int size = data.size();
            for (T element : data) {
              function.apply(element, mapper);
                if ((i % BATCH_SIZE == 0) || i == size) {
                    batchSqlSession.flushStatements();
                }
                i++;
            }
            // 非事务环境下强制commit，事务情况下该commit相当于无效
            batchSqlSession.commit(true);
        } catch (Exception e) {
            batchSqlSession.rollback();
            // throw new BusinessException(e.getMessage());
            log.error("batchUpdateOrInsert", e);
        } finally {
            batchSqlSession.close();
        }
        return i - 1;
    }
}