sql - recursive cte - mark all leafs -

-

i have recursive cte that's working fine, need 1 more thing: add [isleaf] flag each result, tell if record has more children ([leafs] field children counter better).

working example pasted below. counts level of every category , joins names category path, sql server doesn't allow left join, top, select distinct, aggregates , subqueries used in recursive part of cte, obvious methods of doing need.

drop table cats go create table cats(     catid int primary key clustered,     parent int, --parent's catid. 0 top-level entries     name    varchar(255) ) go  insert cats (catid, parent, name) select 1 catid, 0 parent, 'computers' name union      select 2, 1, 'laptops' union          select 4, 2, 'ibm' union          select 5, 2, 'others' union      select 3, 1, 'desktops' union          select 6, 3, 'amd' union          select 7, 3, 'others' union  select  8, 0 , 'cars' union      select 9, 8, 'others' union      select 10, 8, 'pickups' union          select 11, 10, 'others' union          select 12, 10, 'ford' union              select 14, 12, 'ranger' union              select 15, 12, 'others' go        ;with ctecat (     select          catid, parent,         [ctelevel]  = 1,         [ctepath]   = cast(name varchar(4000))         --,[cteisleaf]  = 0     cats     1=1         , parent=0 union      select          c.catid, c.parent,         [ctelevel] = cc.ctelevel+1,         [ctepath] = cast(cc.ctepath + ' | ' + c.name varchar(4000))         --,[cteisleaf]  = 0 --???--     cats c     join ctecat cc         on c.parent = cc.catid     1=1         , c.parent<>0 ) select      *  ctecat order      catid

easiest thing implement add corraleted subquery in final select statement checks isleaf. it's simple check see if particular catid someone's parent or not. not require recursion. 

select     * ,  case when exists (select * cats c2 c2.parent = c1.catid) 0 else 1 end isleaf ctecat c1 order     catid

edit: if need [leafs] count of imminent children it's simple them:

select     *      , case when exists (select * cats c2 c2.parent = c1.catid) 0 else 1 end isleaf     , (select count(*) cats c2 c2.parent = c1.catid) leafs ctecat c1 order      c1.catid

sqlfiddle demo

but, if need [leafs] total counter of children , of chieldren's children require rewriting cte (to go bottom-up instead of top-to-bottom).


Comments

Post a Comment

Popular posts from this blog

java - activate/deactivate sonar maven plugin by profile? -

-
i use sonar plugin executes if activated in maven profile. sonar runs on every compile. the problem build fail other team members not have sonar application installed locally. pom.xml checked in team members same copy including sonar configuration, don't want them modify purpose of disabling sonar (they might inadvertently check modified copy in). please advise how configure maven (.m2/settings.xml) and/or pom.xml sonar feature can enabled/disabled local profile. here sonar configuration in each project's pom.xml: <plugin> <groupid>org.codehaus.mojo</groupid> <artifactid>sonar-maven-plugin</artifactid> <version>1.0</version> <executions> <execution> <id>make-sonar</id> <phase>compile</phase> <goals> <goal>sonar</goal> </goals> </execution> </executions> ...
Read more

python - TypeError: can only concatenate tuple (not "float") to tuple -

-
i'm new python, question might easy, anyway, patience: as trying call newton-raphson method calculate implied volatility in black-scholes formula call/put option pricing, first thing is, newton method in scipy.optimize seems calculate function's zeros, in black-scholes formula, want function's value option price, not zero. (i'm new here programming, i'm not sure techniques.) should write function things like: def f(sigma, price): return bsformula(s0,k,r,t,q,sigma) - price then, while calling newton method, takes args=() 1 parameter in function, write this: value = newton(bsprice2, 0.5, args=price) but error message: file "bs.py", line 36, in bsimpvol value = newton(bsprice2, 0.5, args=float(price)) file "/usr/lib/python2.7/dist-packages/scipy/optimize/zeros.py", line 143, in newton q0 = func(*((p0,) + args)) typeerror: can concatenate tuple (not "float") tuple could tell me why that? how fix it? apprecia...
Read more

java - What is the difference between String. and String.this. ? -

-
this question has answer here: meaning of .this , .class in java 2 answers i'll straight point. im still learning bit of syntax , want know difference between code is code a: public class buttonz extends jbutton{ public buttonz(){ settext(new string(string.valueof(i))); } } please ignore fact i undeclared, not lost. code b: public class buttonz extends jbutton{ public buttonz(){ settext(new string(string.this.charat(i))); } } what don't yet understand difference in typing string.this , string. i under assumption when use dot operator on class accessing it's static methods(and/or variables if they're not hidden). i have studied little bit , have concluded when using string. accessing string static methods.. when using string.this. i'm accessing methods class buttonz extendi...
Read more