Question

我继承了一个数据库，我试图从中提取一些信息。我可以在没有任何问题的情况下完成我想要的SQL，但我真的不知道从哪个查询开始。

有四个与查询相关的表格如下：

Clients

ID  |  Client Name | Client Reference
-------------------------------------
1   | Acme Inc     | ACM
2   | Sprocket Inc | SPR

Customers_Table

ID  | Client | Customer Name
----------------------------
1   | 1      | Fred
2   | 1      | Sarah
3   | 2      | Mary
4   | 2      | Dave

Custom_Questions

ID  | Client | Question
---------------------------------------------------
1   | 1      | What is the name of your dog?
2   | 1      | How old is your dog?
3   | 2      | What is your cat's name?
4   | 2      | When was the cat's last vet visit?

Answers

ID | Customer | Question | Answer
---------------------------------
1  | 1        | 1        | Rover
2  | 1        | 2        | 10
3  | 2        | 1        | Bob
4  | 2        | 2        | 1
5  | 3        | 3        | Trixie
6  | 3        | 4        | Never
7  | 4        | 3        | Furball
8  | 4        | 4        | Last year

系统拥有可以拥有多个客户的客户。客户可以向客户询问可变数量的自定义问题。自定义问题在一个表中，答案在另一个表中。

基本上，我需要为每个客户创建一份报告，列出客户，问题和答案，如下所示：

Client 1 Report:

Customer Name | What is the name of your dog? | How old is your dog?
====================================================================
Fred          | Rover                         | 10
Sarah         | Bob                           | 1

它似乎有点像excel数据透视表，但我无法在Google上找到任何适合的内容。谁能给我一些关于我应该搜索什么或者我应该看什么命令的指示？

由于

Answer 1

IF OBJECT_ID ('tempdb..#Clients') is not null drop table #Clients
IF OBJECT_ID ('tempdb..#Answers') is not null drop table #Answers
IF OBJECT_ID ('tempdb..#CustomQuestions') is not null drop table #CustomQuestions
IF OBJECT_ID ('tempdb..#CustomersTable') is not null drop table #CustomersTable
IF OBJECT_ID ('tempdb..#Holding') is not null drop table #Holding


DECLARE @ID int --this is the client ID of interest
SET @ID = 1

--create some work tables for testing

create table #Clients(
ID int,
ClientName varchar(128),
ClientReference varchar(3))

insert into #Clients (ID, ClientName, ClientReference) values
(1,'Acme Inc','ACM'),
(2,'Sproket Inc', 'SPR')


create table #CustomersTable(
ID int,
Client int,
CustomerName varchar(128))

insert into #CustomersTable(ID, Client,CustomerName) values
(1,1,'Fred'),
(2,1,'Sarah'),
(3,2,'Mary'),
(4,2,'Dave')


create table #CustomQuestions(
ID int,
Client int,
Question varchar(max))

insert into #CustomQuestions (ID, Client, Question) values
(1,1,'What is the name of your dog'),
(2,1,'How old is your dog'),
(3,2,'What is your cats name'),
(4,2,'When was the cats last visit')

create table #Answers(
ID int,
Customer int,
Question int,
Answer varchar(max))

insert into #Answers(ID, Customer,Question, Answer) values
(1,1,1,'Rover'),
(2,1,2,'10'),
(3,2,1,'Bob'),
(4,2,2,'1'),
(5,3,3,'Trixie'),
(6,3,4,'Never'),
(7,4,3,'Furball'),
(8,4,4,'Last year')


--get your data for the client you need

select
    c.ClientName,
    ct.CustomerName,
    q.Question,
    a.Answer
into #Holding
from
    #Clients c
    inner join #CustomersTable ct on
    ct.Client = c.ID
    inner join #Answers a on
    a.Customer = ct.ID
    inner join #CustomQuestions q on
    q.id = a.Question
where
    c.ID = @ID


--Now piviot, with a dynamic amount of questions

DECLARE @DynamicPivotQuery AS NVARCHAR(MAX)
DECLARE @ColumnName AS NVARCHAR(MAX)


SELECT @ColumnName= ISNULL(@ColumnName + ',','') 
       + QUOTENAME(Question)
FROM (SELECT DISTINCT Question FROM #Holding) AS Question

--Prepare the PIVOT query using the dynamic 
SET @DynamicPivotQuery = 
  N'SELECT CustomerName, ' + @ColumnName + '
    FROM #Holding
    PIVOT(Max(Answer) 
          FOR Question IN (' + @ColumnName + ')) AS PVTTable'

EXEC sp_executesql @DynamicPivotQuery

可变行数作为表标题，下面有数据

1 个答案: