学习目标：

学习内容：

一、mybaits-plus 使用注解方式实现批量添加、修改、删除

1. 批量添加

/**
 * 批量新增
 */
@Insert({
        "<script>",
        "INSERT INTO session_event (id, session_id, create_time, data_contexts)",
        "VALUES",
        "<foreach collection ='list' item='sessionEvent' separator =','>",
        "(#{sessionEvent.id}, #{sessionEvent.sessionId}, #{sessionEvent.createTime}, #{sessionEvent.dataContexts})",
        "</foreach>",
        "</script>"
})
int sessionIdInsert(List<SessionEvent> sessionEvent);

2. 批量修改

/**
 * 批量新增
 */
@Update({
        "<script>",
        "<foreach collection='list' item='sessionEvent' index='index' separator=';'>",
        "UPDATE session_event SET",
        "data_contexts = #{sessionEvent.dataContexts}",
        "WHERE session_id = #{sessionEvent.sessionId}",
        "</foreach>",
        "</script>"
})
int sessionIdUpdate(List<SessionEvent> sessionEvent);

3. 批量删除

/**
 * 批量删除
 * @param sessionId
 * @return
 */
@Delete({
        "<script>",
        "DELETE FROM session_event WHERE id IN",
        "<foreach collection='list' item='sessionId' open='(' separator=',' close=')'>",
        "#{sessionId}",
        "</foreach>",
        "</script>"
})
int sessionIdDelete(List<String> sessionId);

4. 根据ids查询列表

/**
 * 批量查询
 * @param sessionId
 */
@Select({
        "<script>",
        "SELECT * FROM session_event",
        "WHERE session_id in",
        "<foreach item='sessionId' index='index' collection='list' open='(' separator=',' close=')'>",
        "#{sessionId}",
        "</foreach>",
        "</script>"
})
public List<SessionEvent> sessionIdSelect(List<String> sessionId);

二、List分页查询

1.mybatis分页
PageHelper.startPage(pageIndex, pageSize);
List<HumitureHis> humitureHisInterval = ...;
return new PageInfo<>(humitureHisInterval);

2.假分页
Page page = new Page(pageIndex, pageSize);
int total = humitureHisInterval.size();
page.setTotal(total);
int startIndex = (pageIndex - 1) * pageSize;
int endIndex = Math.min(startIndex + pageSize,total);
page.addAll(humitureHisInterval.subList(startIndex,endIndex));
PageInfo<HumitureHis> result = new PageInfo<>(page);
return result;

学习时间：

2021-12-08

总结：

便于查看

备注
mybatis做批量更新的时候控制台报错updateBatch-Inline，需要在url上添加characterEncoding=utf8&autoReconnect=true&zeroDateTimeBehavior=convertToNull&useSSL=false&allowMultiQueries=true