Може би нещо подобно:
Първо малко тестови данни:
CREATE TABLE Flight(FlightId int,FlightNumber varchar(10))
CREATE TABLE FlightCapacity(ID int,FlightIdRef int,ClassIdRef int,Capacity int)
CREATE TABLE Class(ClassId int,Name varchar(10))
INSERT INTO Class VALUES(1,'Y'),(2,'A')
INSERT INTO Flight VALUES(1,123),(2,423)
INSERT INTO FlightCapacity VALUES(1,1,1,10),(2,1,2,20),(3,2,2,10)
След това трябва да получите уникалните колони по следния начин:
DECLARE @cols VARCHAR(MAX)
SELECT @cols = COALESCE(@cols + ','+
QUOTENAME('ClassNameAndCapacity'+CAST(ClassId AS VARCHAR(10))),
QUOTENAME('ClassNameAndCapacity'+CAST(ClassId AS VARCHAR(10))))
FROM
Class
Декарингът и изпълнението на динамичния sql:
DECLARE @query NVARCHAR(4000)=
N'SELECT
*
FROM
(
SELECT
Flight.FlightNumber,
Class.Name+CAST(FlightCapacity.Capacity AS VARCHAR(100)) AS ClassName,
''ClassNameAndCapacity''+CAST(Class.ClassId AS VARCHAR(10)) AS ClassAndCapacity
FROM
Flight
JOIN FlightCapacity
ON Flight.FlightId=FlightCapacity.FlightIdRef
JOIN Class
ON FlightCapacity.ClassIdRef=Class.ClassId
) AS p
PIVOT
(
MAX(ClassName)
FOR ClassAndCapacity IN('[email protected]+')
) AS pvt'
EXECUTE(@query)
И тогава в моя случай ще премахна създадените таблици:
DROP TABLE Flight
DROP TABLE Class
DROP TABLE FlightCapacity