SQL Server : how to use SQL statements to get the desired results -

-

i can use cursors, it's inefficient. there better way use sql statements these results?

table： a

a1    id      a2 -------------------- aaa        8:30 bbb        9:30 ccc        10:00

table： b

id    ​b2 ----------    8:30    9:00    9:10    9:30    9:50    10:01    12:00

desired results：

id    b2    ​    ​a1 ---------------------    8:30    ​    ​aaa    9:00    ​    ​aaa    9:10    ​    ​aaa    9:30    ​    ​bbb    9:50    ​    ​bbb    10:00    ​    ​bbb    10:01       ccc        12:00       ccc

although not have method achieve,

because explanation not enough.you should explain why 9:30 ​bbb , why 10:00 bbb

i tried using sql server 2012+ 

declare @t table(a1 varchar(50),id varchar(50), a2 time) insert @t values  ('aaa','a','8:30') ,('bbb','a','9:30') ,('ccc','a','10:00')    --select *,lead(a2,1)over(order id ) a2_endtime @t  declare @t1 table(id varchar(50), ​b2 time) insert @t1 values  ('a','8:30') ,('a','9:00') ,('a','9:10') ,('a','9:30') ,('a','9:50') ,('a','10:01') ,('a','12:00')  ;with cte (  select *,lead(a2,1)over(order id ) a2_endtime @t ) --select * cte ,cte1 (select t1.id,t1.b2 @t1 t1 ) ,cte2 ( select * @t c not exists(select b2 cte1 c1 c1.b2=c.a2) ) ,cte3 ( select id,b2 cte1 union select id,a2 cte2  )  select t1.id,t1.b2  ,(select top 1 t.a1  cte t ((t.a2_endtime null , t1.b2>=t.a2 )  or (t.a2_endtime not null , (t1.b2 >= t.a2 , t1.b2< t.a2_endtime) ))) cte3 t1

Comments

Post a Comment

Popular posts from this blog

Django REST Framework perform_create: You cannot call `.save()` after accessing `serializer.data` -

-
i have following viewset: class artistprofileviewset(viewsets.modelviewset): queryset = artistprofile.objects.all() serializer_class = artistprofileserializer def perform_create(self, serializer): if serializer.is_valid(): serializer.save() with following serializers: class simpleartisttrackserializer(serializers.hyperlinkedmodelserializer): class meta: model = artisttrack fields = (...my fields...) class artistprofileserializer(serializers.hyperlinkedmodelserializer): owners = userserializer(many=true, required=false) tracks = simpleartisttrackserializer(many=true, required=false) class meta: model = artistprofile fields = (...my fields...) i getting following error: assertionerror: cannot call `.save()` after accessing `serializer.data`.if need access data before committing database inspect 'serializer.validated_data' instead. i don't see editing serializer.data object. th...
Read more

Why does Go error when trying to marshal this JSON? -

-
i'm trying rather simple example of trying decode json file structs using golang. however, when attempting error that json: cannot unmarshal object go value of type []main.track which don't understand. here's code in question, , json can found here . package main import ( "encoding/json" "fmt" "net/http" "os" ) // tracks group of track types type tracks struct { tracks []track } // track represents singular track type track struct { name string url string artist artist } // artist represents single artist type artist struct { name string mbid string url string } func main() { url := "http://ws.audioscrobbler.com/2.0/?method=geo.gettoptracks&api_key=c1572082105bd40d247836b5c1819623&format=json&country=netherlands" response, err := http.get(url) if err != nil { fmt.printf("%s\n", err) os.exit(1) } de...
Read more