Matrix table SQL - sql

Question

I have three tables:
Table tCity
(Id int, City nvarchar(50))
Table tLocation
(Id int, Location nvarchar(50))
Table tCityLocation
(Id int, CityId int, LocationId int)
I would like to generate matrix table like in image below.
If City belongs to location-> in appropriate cell in table, char X will be written down.
I would like to about any sophisticated approach how to reach it. I had issue in similar logic and processed by iteration in cursors with dynamically added column to result set table.
Exists any sophisticated approach instead of cursor and dynamically added column?
Thank you.

Answer 1

It should be something like this:
DECLARE #DymanimcTSQLSatement NVARCHAR(MAX)
,#DynamicColumns NVARCHAR(MAX);
SET #DynamicColumns = STUFF
(
(
SELECT ',' + QUOTENAME([Location])
FROM tLocation
GROUP BY [Location]
ORDER BY [Location]
FOR XML PATH(''), TYPE
).value('.', 'NVARCHAR(MAX)')
,1
,1
,''
);
SET #DymanimcTSQLSatement = N'
SELECT *
FROM
(
SELECT L.Location
,C.City
,1
FROM tCityLocation CL
INNER JOIN tLocation L
ON CL.[LocationId] = L.[id]
INNER JOIN tCity C
ON CL.[CityId] = C.[id]
) DS (country, city, value)
PIVOT
(
MAX([value]) FOR [country] IN (' + #DynamicColumns +')
) PVT;';
EXECUTE sp_executesql #DymanimcTSQLSatement;
and here is the data I have used:
-- Creating Table tCity
CREATE TABLE tCity (
Id int,
City nvarchar(50)
);
-- Populating Table tCity with 10 records
INSERT INTO tCity (Id, City) VALUES (1, 'New York');
INSERT INTO tCity (Id, City) VALUES (2, 'Los Angeles');
INSERT INTO tCity (Id, City) VALUES (3, 'Paris');
INSERT INTO tCity (Id, City) VALUES (4, 'Tokyo');
INSERT INTO tCity (Id, City) VALUES (5, 'Sydney');
INSERT INTO tCity (Id, City) VALUES (6, 'Philadelphia');
INSERT INTO tCity (Id, City) VALUES (7, 'Rio de Janeiro');
INSERT INTO tCity (Id, City) VALUES (8, 'Cape Town');
INSERT INTO tCity (Id, City) VALUES (9, 'Beijing');
INSERT INTO tCity (Id, City) VALUES (10, 'Singapore');
-- Creating Table tLocation
CREATE TABLE tLocation (
Id int,
Location nvarchar(50)
);
-- Populating Table tLocation with 10 records
INSERT INTO tLocation (Id, Location) VALUES (1, 'United States');
INSERT INTO tLocation (Id, Location) VALUES (2, 'United States');
INSERT INTO tLocation (Id, Location) VALUES (3, 'France');
INSERT INTO tLocation (Id, Location) VALUES (4, 'Japan');
INSERT INTO tLocation (Id, Location) VALUES (5, 'Australia');
INSERT INTO tLocation (Id, Location) VALUES (6, 'United States');
INSERT INTO tLocation (Id, Location) VALUES (7, 'Brazil');
INSERT INTO tLocation (Id, Location) VALUES (8, 'South Africa');
INSERT INTO tLocation (Id, Location) VALUES (9, 'China');
INSERT INTO tLocation (Id, Location) VALUES (10, 'Singapore');
-- Creating Table tCityLocation
CREATE TABLE tCityLocation (
Id int,
CityId int,
LocationId int
);
INSERT INTO tCityLocation (Id, CityId, LocationId)
SELECT
ROW_NUMBER() OVER (ORDER BY tCity.Id),
tCity.Id, tLocation.Id
FROM tCity
JOIN tLocation
ON tCity.Id = tLocation.Id;
The idea is to built a dynamic PIVOT, where the PIVOT columns are the unique countries (in your case locations). If your SQL Server supports STRING_AGG, you can do this in different way:
SELECT #DynamicColumns = STRING_AGG(CAST(QUOTENAME([Location]) AS VARCHAR(MAX)), ',') WITHIN GROUP (ORDER BY [Location])
FROM
(
SELECT DISTINCT [Location]
FROM tLocation
) DS ([Location]);

Answer 2

Better way for answer to this question use pivot
First I get list Location of table Location
Second I get list Location of table tLocation For use in select
Because I need to use ISNULL for replace null with space
after use pivot for get result
result :Rows include List City and Column include Location
city
Asia
CRezah Rep.
Europe
France
GB
Germany
Japan
N.America
USA
NY
x
x
Prague
x
x
x
London
x
x
Tokio
x
x
--Get List Columns for Pivot
DECLARE #cols AS NVARCHAR(MAX),#scols AS NVARCHAR(MAX),
#query AS NVARCHAR(MAX)
select #cols = STUFF((SELECT distinct ',' + QUOTENAME(Location) from tLocation
FOR XML PATH(''), TYPE ).value('.', 'NVARCHAR(MAX)') ,1,1,'' )
--can to use below Code for Replace null with space
select #scols = STUFF((SELECT distinct ',ISNULL(' + QUOTENAME(Location) +','' '') as '+ QUOTENAME(Location)
from tLocation FOR XML PATH(''), TYPE ).value('.', 'NVARCHAR(MAX)') ,1,1,'')
set #query = 'SELECT city ,'+#scols+' from
(
select cl.CityId,c.City,l.Location,''X'' as Value from tCityLocation cl
inner join tCity c on cl.CityId=c.Id
inner join tLocation l on cl.LocationId=l.Id
) x
pivot
(
max( value) for Location in (' + #cols + ')
) p
order by CityId
'
execute(#query)
You can to insert the basic data with the following codes
create table tCity(Id int, City nvarchar(50))
create table tLocation(Id int, Location nvarchar(50))
create table tCityLocation(Id int, CityId int, LocationId int)
insert into tCity
(id,City)
select 1 as id,'NY' union all select 2 as id,'Prague'
union all select 3 as id,'London' union all select 4 as id,'Tokio'
insert into tLocation (id,Location)
select 1,'USA' union all select 2,'CRezah Rep.' union all select 3,'France' union all select 4,'GB'
union all select 5,'Germany' union all select 6,'Europe' union all select 7,'N.America'
union all select 9,'Asia' union all select 10,'Japan'
insert into tCityLocation
(id,CityId,LocationId)
select 1,1,1 union all select 2,1,7 union all select 3,2,2 union all select 4,2,6 union all select 5,3,4 union all
select 6,3,6 union all select 7,4,9 union all select 8,4,10