this.first_name,this.role,this.manager_id,prior.level+1FROMempdata priorINNERJOINemployee thisONthis.manager_id=prior.id))SELECTe.id,e.first_name,e.role,e.manager_id,e.levelFROMempdataeORDERBYe.level;
Data School wants a comprehensive post with visuals to help people understand storing hierarchical data. Please use stack overflow to understand the various methods:https://stackoverflow.com/questions/4048151/what-are-the-options-for-storing-hierarchical-data-in-a-relational-database The structure of ...
Most users at one time or another have dealt with hierarchical data in a SQL database and no doubt learned that the management of hierarchical data is not what a relational database is intended for. The tables of a relational database are not hierarchical (like XML), but are simply a fla...
SQL Server has not made it easy to represent and store them in relational tables. After SQL Server2000, XML structures are excellent for managing hierarchical data relationships, of course in SQL Server 2005, developers can use recursive queries against data stored hierarchically, but it needs...
The HierarchyId type is more idiomatic to the norms of .NET than SqlHierarchyId, which is instead modeled after how .NET Framework types are hosted inside the SQL Server database engine. HierarchyId is designed to work with EF Core, but it can also be used outside of EF Core in other ap...
Applies to: SQL Server Azure SQL Database Azure SQL Managed Instance SQL database in Microsoft Fabric The built-in hierarchyid data type makes it easier to store and query hierarchical data. hierarchyid is optimized for representing trees, which are the most common type of hierarchical data. ...
原文:http://mikehillyer.com/articles/managing-hierarchical-data-in-mysql/ 引言 大多数用户都曾在数据库中处理过分层数据(hierarchical data),认为分层数据的管理不是关系数据库的目的。之所以这么认为,是因为关系数据库中的表没有层次关系,只是简单的平面化的列表;而分层数据具有父-子关系,显然关系数据库中的表不...
The first common task when dealing with hierarchical data is the display of the entire tree, usually with some form of indentation. The most common way of doing this is in pure SQL is through the use of a self-join: SELECT t1.name AS lev1, t2.name as lev2, t3.name as lev3, t4...
http://dev.mysql.com/tech-resources/articles/hierarchical-data.html Introduction 大多数用户都曾在数据库中处理过分层数据(hierarchical data),认为分层数据的管理不是关系数据库的目的。之所以这么认为,是因为关系数据库中的表没有层次关系,只是简单的平面化的列表;而分层数据具有父-子关系,显然关系数据库中的表不...
sql-serverentity-frameworkhierarchical-datasql-server-2008entity-framework-4 EBa*_*arr lucky-day 14 推荐指数 1 解决办法 2913 查看次数 如何在SQL中递归自我JOIN? 我有一张桌子: Series === ID SeriesName ParentSeriesID 一个系列可以是"根"系列,(ParentSeriesID是0或null)或者它可以有一个父系列.一个...