Question

我在另一篇文章中提到了这个问题但是我已经改变了。我有三张桌子：

Flight table
 FlightId  int
 FlightNumber varchar(10)

FlightCapacity table
ID int
FlightIdRef int
ClassIdRef  int
Capacity    int

Class Table
ClassId  int
Name      varchar(10)

Class Table:
ClassId     Name
   1         Y
   2         A

Flight Table
FlightId   Number
1           123
2           423

FlightCapacity Table
Id   FlightIdRef    ClassIdref  Capacity
1       1              1          10
2       1              2          20
3       2              2          10

这是一个简单的查询：

select Flight.FlightNumber,Class.Name+RTRIM(FlightCapacity.Capacity)
   from  Flight
      inner join FlightCapacity
           on Flight.FlightId=FlightCapacity.FlightIdRef
               inner join Class
                    on FlightCapacity.ClassIdRef=Class.ClassId

但我希望得到以下结果:(我想在一行中显示所有航班和容量的所有类别，但在不同的列中）

FlightNumber     ClassNameAndCapacity1   ClassNameAndCapacity2    ClassNameAndCapacityn
  123                 Y10                         A20                      
  423                 Y10                         ---

Answer 1

也许是这样的：

首先是一些测试数据：

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)

然后你必须得到像这样的独特列：

DECLARE @cols VARCHAR(MAX)
SELECT  @cols = COALESCE(@cols + ','+
                QUOTENAME('ClassNameAndCapacity'+CAST(ClassId AS VARCHAR(10))),
                QUOTENAME('ClassNameAndCapacity'+CAST(ClassId AS VARCHAR(10))))
FROM 
    Class

delcaring并执行动态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('+@cols+')
) AS pvt'

EXECUTE(@query)

然后在我的情况下，我将删除创建的表：

DROP TABLE Flight
DROP TABLE Class
DROP TABLE FlightCapacity

如何显示查询结果columnar（在不同的列中）而不是逐行显示？

1 个答案: