sqlite树型结构查询

sqlite树型结构查询

 

表结构：tblCity(ID, ParentID, Name)

 

因为sqlite 没有row_number函数，也不能递归查询，所幸它有RowID 这个字段。只好采用这种 笨方法

 

1）

 

[sql] 

select ID,Name,1 as Level from tblCity where ParentID=0  

union all   

select a.ID,a.Name,c.RowID as Level from tblCity a   

inner join tblCity b on a.ParentID=b.ID  

inner join   

(  

      select ParentID from tblCity group by ParentID  

) c on a.ParentID=c.ParentID  

 

2）

[sql] 

select ID,Name,1 as Level from tblCity where ParentID=0  

union all   

select a.ID,a.Name,c.RowID as Level from tblCity a   

inner join tblCity b on a.ParentID=b.ID  

inner join   

(  

      select ParentID from tblCity group by ParentID  

) c on a.ParentID=c.ParentID