Pivot sur plusieurs lignes dynamiques

Question

Comment puis-je obtenir cet ensemble de données que j'ai créé en utilisant le pivot. pour ressembler à ceci comme ces données qui est ce qui est nécessaire pour moi d'afficher

Country town1  City1  town2  City2  town3 City3  town4 City4  town5 City5 
India NULL  NULL  NULL  NULL  NULL NULL  townin India Town NULL NULL 
India NULL  NULL  NULL  NULL  Del  New Delhi NULL NULL  NULL NULL 
India NULL  NULL  Bang  Bangalore NULL NULL  NULL NULL  NULL NULL 
India hyder  Hyderabad NULL  NULL  NULL NULL  NULL NULL  NULL NULL 
UK  NULL  NULL  NULL  NULL  United Manchester NULL NULL  NULL NULL 
UK  NULL  NULL  sunderland Birmingham NULL NULL  NULL NULL  NULL NULL 
UK  chelsea  London  NULL  NULL  NULL NULL  NULL NULL  NULL NULL 
USA  NULL  NULL  NULL  NULL  Dally Dallas  NULL NULL  NULL NULL 
USA  NULL  NULL  houst  Houston  NULL NULL  NULL NULL  NULL NULL 
USA  New Jersy New York NULL  NULL  NULL NULL  NULL NULL  NULL NULL 

:

Country town1  City1  town2  City2  town3 City3  town4 City4  town5 City5 
India hyder  Hyderabad Bang  Bangalore Del  New Delhi townin India Town NULL NULL 
UK  chelsea  London  sunderland Birmingham United Manchester NULL NULL  NULL NULL 
USA  New Jersy New York houst  Houston  Dally Dallas  NULL NULL  NULL NULL 

mes créer et d'insérer le code ci-dessous a été utilisé:

Create Table Countries 
(
    Country nvarchar(50), 
    Town nvarchar(50), 
    City nvarchar(50) 
) 
GO 

Insert into Countries values ('USA','New Jersy','New York') 
Insert into Countries values ('USA','houst','Houston') 
Insert into Countries values ('USA','Dally','Dallas') 

Insert into Countries values ('India','hyder','Hyderabad') 
Insert into Countries values ('India','Bang','Bangalore') 
Insert into Countries values ('India','Del','New Delhi') 
Insert into Countries values ('India','townin','India Town') 

Insert into Countries values ('UK','chelsea','London') 
Insert into Countries values ('UK','sunderland','Birmingham') 
Insert into Countries values ('UK','United','Manchester') 

Code pivot actuel basé sur quelques blogs et vidéos:

Select Country, town1, City1, town2, City2, town3, City3, town4, City4, town5, City5 
From 
(
Select Country, City, 'City'+ cast(row_number() over(partition by Country order by Country) as varchar(10)) ColumnSequence, 
Town, 'Town'+ cast(row_number() over(partition by Country order by Country) as varchar(10)) ColumnSequence2 
from Countries 
) Temp 
pivot 
(
max(City) 
for ColumnSequence in (City1, City2, City3, City4, City5) 
) Piv 
pivot 
(
max(Town) 
for ColumnSequence2 in (town1, town2, town3, town4, town5) 
) Piv 
group by Country, town1, City1, town2, City2, town3, City3, town4, City4, 
town5, City5 

Answer 1

COALESCE est la fonction que vous recherchez. Il retournera la première valeur non nulle. Plus d'infos ici:

https://docs.microsoft.com/en-us/sql/t-sql/language-elements/coalesce-transact-sql

Answer 2

utilisant row_number() et l'agrégation conditionnelle pour faire pivoter vos données:

select 
    Country 
    , Town_01 = max(case when rn = 1 then Town end) 
    , City_01 = max(case when rn = 1 then City end) 
    , Town_02 = max(case when rn = 2 then Town end) 
    , City_02 = max(case when rn = 2 then City end) 
    , Town_03 = max(case when rn = 3 then Town end) 
    , City_03 = max(case when rn = 3 then City end) 
    , Town_04 = max(case when rn = 4 then Town end) 
    , City_04 = max(case when rn = 4 then City end) 
from (
    select * 
    , rn = row_number() over (partition by Country order by Town) 
    from Countries 
) as t 
group by Country 

rextester démonstration: http://rextester.com/GYV10206

retours:

+---------+---------+-----------+------------+------------+-----------+------------+---------+------------+ 
| Country | Town_01 | City_01 | Town_02 | City_02 | Town_03 | City_03 | Town_04 | City_04 | 
+---------+---------+-----------+------------+------------+-----------+------------+---------+------------+ 
| India | Bang | Bangalore | Del  | New Delhi | hyder  | Hyderabad | townin | India Town | 
| UK  | chelsea | London | sunderland | Birmingham | United | Manchester | NULL | NULL  | 
| USA  | Dally | Dallas | houst  | Houston | New Jersy | New York | NULL | NULL  | 
+---------+---------+-----------+------------+------------+-----------+------------+---------+------------+ 

Answer 3

Essayez ce code :

with cte as 
(Select Country, min(town1) as town1, min(City1) as City1, min(town2)as town2, min(City2)as City2, min(town3)as town3, 
min(City3) as City3, min(town4) as town4, min(City4) as City4, min(town5) as town5, min(City5) as City5 
From 
(
Select Country, City, 'City'+ cast(row_number() over(partition by Country order by Country) as varchar(10)) ColumnSequence, 
Town, 'Town'+ cast(row_number() over(partition by Country order by Country) as varchar(10)) ColumnSequence2 
from Countries 
) Temp 
pivot 
(
max(City) 
for ColumnSequence in (City1, City2, City3, City4, City5) 
) Piv 
pivot 
(
max(Town) 
for ColumnSequence2 in (town1, town2, town3, town4, town5) 
) Piv 
group by Country) 
Select t.Country, COALESCE(t.town1,d.town1), COALESCE(t.City1,d.city1), COALESCE(t.town2,d.town2), 
COALESCE(t.City2,d.city2), COALESCE(t.town3,d.town3), COALESCE(t.City3,d.city3), COALESCE(t.town4,d.town4), 
COALESCE(t.City4,d.city4), COALESCE(t.town5,d.town5), COALESCE(t.City5,d.city5) 
from cte d iNNER JOIN CTE t ON d.country = t.country