sql 查询嵌套计数

Question

我有一个 table 存储成员数据和父引用的地方

如果 HU1 是父 ID 我的意思是 spos 我如何计算 HU1 下的总 mid 和嵌套的子 mid

例如，看到 HU5 在 HU1 下，HU6 在 HU5 下，那么我如何计算在父 HU1 下的嵌套 MID 总数这里 HU1 的总计数是 10 我如何从 sql 查询

中得到这个

我用mysql5.0

我试过了

SELECT parent.mid, COUNT(child.mid) AS child_count FROM member parent INNER JOIN member child ON child.spos = parent.mid WHERE child.spos = 'HU1' GROUP BY parent.mid;

但它只显示 2 而不是 10

和

SELECT mid,spos,(SELECT count(unit) from member where spos=spos and spos='HU1')as totaspos from member where spos='HU1'

它也只显示 2 而不是 10

Answer 1

我会在数据库外部以编程方式执行此操作，获取整个 table 行或新行，直到找不到子项。

如果已知树的最大深度，这是可能的，但这是一个非常昂贵的操作。您基本上必须将 table 加入到它自己的次数与最大深度相同。

Answer 2

这是另一个想法...

DROP TABLE IF EXISTS my_table;

CREATE TABLE my_table
(spos VARCHAR(12) NOT NULL PRIMARY KEY
,lft INT NOT NULL
,rgt INT NOT NULL
);

INSERT INTO my_table VALUES
('HU1' ,1,22),
('HU2' ,2,3),
('HU3' ,4,5),
('HU4' ,6,7),
('HU5' ,8,21),
('HU6' ,9,20),
('HU7' ,10,19),
('HU8' ,11,18),
('HU9' ,12,17),
('HU10',13,16),
('HU11',14,15);

SELECT COUNT(*) 
  FROM my_table x 
  JOIN my_table y 
    ON y.lft > x.lft 
   AND y.rgt < x.rgt 
 WHERE x.spos = 'HU1';

+----------+
| COUNT(*) |
+----------+
|       10 |
+----------+
1 row in set

Answer 3

不使用 Sql 查询，但我使用函数管理它我想分享完整的页面代码，希望这会对某人有所帮助

<!--#include file="mrraja.asp"-->
<style>
.propertyDetails td{text-align: left; padding-left: 1em;width: 10%;}
a{cursor: pointer;}
</style>   
<div class="container">
<div class="col-md-12 wow fadeInLeft" data-wow-delay="0.4s">
<div class="living_box" style="height: 30em;overflow: auto;">
<% 
Set allspos=TheDB.Execute("SELECT COUNT(*) as totdir FROM member where spos='"&iam("mid")&"' ORDER BY sl asc")
if not allspos.eof=true then
totdirme=allspos("totdir")
else
totdirme=0
end if
%>  
<div class="living_desc">
    <a href="#" class="btn3">Full Team Detail</a>
    <p class="price">Total Directs: <%=totdirme%></p>
    </div>    
<table border="1" class="propertyDetails">
                <tbody>
                <tr>
                   <td>MID</td>
                   <td>NAME</td>
                   <td>SPONSOR</td>
       <td>MOBILE</td>
                   <td>ACTIVE</td>
                   <td>COUNT</td>
    </tr>   
<%
    Dim countrec:countrec=0
 Dim countunit:countunit=0
 Dim unt:unt=0
 Dim tunt:tunt=0   
 call GET_HASAN(CStr(iam("mid")))   
'===============  
Public Sub GET_HASAN(MRRAJA)
sel = " SELECT mid FROM member where  spos='" & MRRAJA & "' order by mid asc "
Set rs = TheDB.Execute(sel)
Do while Not rs.eof=true
If Not rs.EOF = True Then
l = rs.Fields(0)  
Else
l = 0
End If
Call GET_IDEA1((l))
rs.MoveNext    
Loop     
rs.Close
Set rs = Nothing        
End Sub
'------------------------------    
Public Sub GET_IDEA1(MRRAJA)                
call SET_ME(CStr(MRRAJA))
sel = " SELECT mid FROM member where  spos='" & MRRAJA & "' order by mid asc "
Set rs = TheDB.Execute(sel)
Do while Not rs.eof=true
If Not rs.EOF = True Then
l = rs.Fields(0)
Call GET_IDEA1((l))
Else
l = 0
levelL=levelL+1  
End If  
rs.MoveNext    
Loop    
rs.Close
Set rs = Nothing
End Sub
    '=============== 
Public Sub SET_ME(MRRAJA) 
sel = " SELECT * FROM member where  mid='" & MRRAJA & "' order by mid asc "
Set rs = TheDB.Execute(sel)
If Not rs.EOF = True Then
mid1=cstr(rs("mid"))
fname=rs("fullname")
snme=rs("spos")
sps=rs("spos")
mob=rs("mob")
address=(rs("addrs"))+" "+(rs("city"))+" "+(rs("dist"))
pkg=rs("act")
if pkg="YES" then
countunit=1
unt=unt+rs("unit")
else
countunit=0
unt=unt
end if
tunt=tunt+rs("unit") 
mob=rs("mob")
End if
rs.close
Set rs = Nothing
%>
    <tr>
                   <td><%=mid1%></td>
                   <td><%=fname%></td>
                   <td><%=snme%></td>
       <td><%=mob%></td>
                   <td><%=pkg%></td>
                   <td><%=countunit%></td>
    </tr>  
<%End Sub%>         
    <tr>
                   <td colspan="2">Total: <%=tunt%></td>
       <td colspan="2">Active: <%=unt%></td>
       <td colspan="2">Inactive: <%=tunt-unt%></td>
    </tr>              
    
                </tbody></table>    
    </div>
   </div>
      </div>
   </div></div>

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