(抱歉,SQL新手)。 我有下表,用户可以更新和/或添加到:
Project Type:
ID Name
1 Documents
2 DVD
3 Poster
我有一个查询,部分需要遍历每条记录并创建一个(pivot?):
...
sum (case when Project.Name = Documents then 1 else 0 end) as NumOf + Documents
sum (case when Project.nextvalue = nextvalue then 1 else 0 end) as NumOf + nextvalue
...
...然后遍历表中的每条记录。
所以结果如下:
ProductName NumOfDocuments NumOfDVD NumOfPoster
Product A 6 0 4
Product B 13 3 8
Product C 2 0 1
这可能吗?
修改
这是我当前的查询:
SELECT
Clients.ID,
Products.Name,
sum(case when ProjectTypes.Name = 'Abstracts' then 1 else 0 end) as NumAbstracts
FROM Clients
INNER JOIN Products ON Clients.ID = Products.ClientID
INNER JOIN Projects ON Products.ID = Projects.ProductID
INNER JOIN ProjectTypes ON Projects.ProjectTypeID = ProjectTypes.ID
GROUP BY
Clients.ID,
Products.Name,
Projects.ProjectTypeID
/*
SCHEMA
Clients: ID | Name
Products: ID | Name | Client ID
Projects: ID | Name | ProductID | ProjectTypeID
ProjectTypes: ID | Name
*/
答案 0 :(得分:1)
您可以使用条件聚合完成此操作,就像您列出的那样。
SELECT
ProductName,
SUM(CASE WHEN Name = 'Documents' THEN 1 ELSE 0 END) as NumOfDocuments,
SUM(CASE WHEN Name = 'DVD' THEN 1 ELSE 0 END) as NumOfDVD,
SUM(CASE WHEN Name = 'Poster' THEN 1 ELSE 0 END) as NumOfPoster
FROM
YourTable
GROUP BY ProductName
DYNAMIC SQL
IF OBJECT_ID('tempdb..#Clients') IS NOT NULL DROP TABLE #Clients
IF OBJECT_ID('tempdb..#Products') IS NOT NULL DROP TABLE #Products
IF OBJECT_ID('tempdb..#Projects') IS NOT NULL DROP TABLE #Projects
IF OBJECT_ID('tempdb..#ProjectTypes') IS NOT NULL DROP TABLE #ProjectTypes
CREATE TABLE #Clients (ID int, Name varchar(64))
CREATE TABLE #Products (ID int, Name varchar(64), ClientID int)
CREATE TABLE #Projects (ID int, Name varchar(64), ProductID int, ProjectTypeID int)
CREATE TABLE #ProjectTypes (ID int, Name varchar(64))
INSERT INTO #Clients (ID, Name) VALUES
(1,'Client1'),
(2,'Client2'),
(3,'Client3'),
(4,'Client4')
INSERT INTO #Products (ID, Name, ClientID) VALUES
(1,'Prod1',1),
(2,'Prod2',1),
(3,'Prod3',1),
(2,'Prod2',2),
(2,'Prod2',3),
(3,'Prod3',3),
(4,'Prod3',3)
INSERT INTO #Projects (ID, Name, ProductID, ProjectTypeID) VALUES
(1,'Proj1',1,1),
(1,'Proj1',2,1),
(1,'Proj1',3,1),
(2,'Proj2',2,2),
(2,'Proj2',3,2),
(2,'Proj2',4,2),
(3,'Proj3',4,3)
INSERT INTO #ProjectTypes (ID, Name) VALUES
(1,'ProjType1'),
(2,'ProjType2'),
(3,'ProjType3')
IF OBJECT_ID('tempdb..#Summary') IS NOT NULL DROP TABLE #Summary
SELECT
c.ID,
prod.Name as ProductName,
proj.Name as ProjectName,
projT.Name as ProjType
INTO #Summary
FROM #Clients c
INNER JOIN
#Products prod on prod.ClientID = c.ID
INNER JOIN
#Projects proj on proj.ProductID = prod.ID
INNER JOIN
#ProjectTypes projT on projT.ID = proj.ProjectTypeID
SELECT * FROM #Summary
DECLARE @DynamicPivotQuery AS NVARCHAR(MAX)
DECLARE @ColumnName AS NVARCHAR(MAX)
--Get distinct values of the PIVOT Column
SELECT @ColumnName= ISNULL(@ColumnName + ',','')
+ QUOTENAME(ProjType)
FROM (SELECT DISTINCT ProjType FROM #Summary) AS Names
--Prepare the PIVOT query using the dynamic
SET @DynamicPivotQuery =
N'SELECT ProductName, ' + @ColumnName + '
FROM #Summary
PIVOT(COUNT(ProjType)
FOR ProjType IN (' + @ColumnName + ')) AS PVTTable'
--Execute the Dynamic Pivot Query
EXEC sp_executesql @DynamicPivotQuery
所以使用你的表,你应该能够运行它...它可能需要稍微调整。
IF OBJECT_ID('tempdb..#Summary') IS NOT NULL DROP TABLE #Summary
SELECT
c.ID,
prod.Name as ProductName,
proj.Name as ProjectName,
projT.Name as ProjType
INTO #Summary
FROM Clients c
INNER JOIN
Products prod on prod.ClientID = c.ID
INNER JOIN
Projects proj on proj.ProductID = prod.ID
INNER JOIN
ProjectTypes projT on projT.ID = proj.ProjectTypeID
DECLARE @DynamicPivotQuery AS NVARCHAR(MAX)
DECLARE @ColumnName AS NVARCHAR(MAX)
--Get distinct values of the PIVOT Column
SELECT @ColumnName= ISNULL(@ColumnName + ',','')
+ QUOTENAME(ProjType)
FROM (SELECT DISTINCT ProjType FROM #Summary) AS Names
--Prepare the PIVOT query using the dynamic
SET @DynamicPivotQuery =
N'SELECT ProductName, ' + @ColumnName + '
FROM #Summary
PIVOT(COUNT(ProjType)
FOR ProjType IN (' + @ColumnName + ')) AS PVTTable'
--Execute the Dynamic Pivot Query
EXEC sp_executesql @DynamicPivotQuery