The grouping works well but it record displayed in the group is the first recorded entered into the DB but I would like the latest record to be displayed in each group. Is there a way to have the latest record displayed for each group? 2011-12-19 12:16:25 This is the first message ...
Re: SELECT the LATEST Record FOR Each UserID Rick James March 25, 2012 03:17PM Sorry, you can't reply to this topic. It has been closed. Content reproduced on this site is the property of the respective copyright holders. It is not reviewed in advance by Oracle and does not necessaril...
<select id="selectByIdList" resultType="SysUser"> select id, user_name userName, user_password userPassword, user_email userEmail, user_info userInfo, head_img headImg, create_time createTime from sys_user where id in <foreach collection="list" open="(" close=")" separator="," item="...
7、 unique_subquery该类型替换了下面形式的IN子查询的ref: value IN (SELECT primary_key FROM single_table WHERE some_expr) unique_subquery是一个索引查找函数,可以完全替换子查询,效率更高。 8、 index_subquery该联接类型类似于unique_subquery。可以替换IN子查询,但只适合下列形式的子查询中的非唯一索引: va...
So basically we have an option of adding a column that returns the latest record, for each group last row(or first depend on your query) added a flag last= 1, and make all other rows’ flag last= 0. 1. By Trigger 2. By Manual programming changes Which ever works for ...
The SQL statement that is used for refined data filtering. If you configure this parameter, data is filtered based only on the value of this parameter. For example, if you want to join multiple tables for data synchronization, set this parameter toselect a,b from table_a join table_b on...
For example, set the CheckPoint Column Name parameter to id, the Initial Value of CheckPoint Column parameter to 0, and the SELECT Statement parameter to SELECT * FROM xxx WHERE ID > ?. Each time Logtail executes the SELECT statement, the system saves the ID of the last data record as th...
Select Operating System: Recommended Download: Other Downloads: Windows (x86, 64-bit), MSI Installer8.0.4142.0M Download (mysql-workbench-community-8.0.41-winx64.msi)MD5:11b6e354f0f2ba5ea089a6e8ab5bc47d|Signature We suggest that you use theMD5 checksums and GnuPG signaturesto verify the int...
前置概念 无并发的解决方案 一些小型项目,或极少有并发的项目,这些策略在无并发情况下,不会有什么问题。 读数据策略:有缓存则读缓存,然后接口返回。没有缓存,查询出数据,载入缓存,然后接口返回。 写数据策略:数据发生了变动,先删除缓存,再更新数据,等下次读取的
最近,在瑞典MySQL用户组 (SMUG) 期间,我举办了一场专门讨论MySQL InnoDB 主键的会议。 我忘了提一个很多人都不知道的细节,但Jeremy Cole 已经指出了。 主键始终包含在最右侧列的二级索引中 当我们定义二级索引时,二级索引将主键作为索引最右侧的列。它是默默添加的,这意味着它不可见,但用于指向聚集索引中的记录...