1

我有一个关于 SQL Server 查询的问题。

这些表可以描述如下：

  • 供应商( SID, sName, status, sCity), PK = SID

  • 零件( PID, pName, color, weight, pCity)，PK = PID

  • 项目( JID, jName, city), PK = JID

  • SPJ ( SID, PID, JID, quantity), PK = (SID, PID, JID), FK = SID, PID, JID

我正在尝试为至少两个项目的同一部分的供应商获取供应商编号和名称，这是我对该任务的查询：

SELECT 
    s1.SID, s1.sName, COUNT(*)
FROM 
    Suppliers s1, Parts p, SPJ s2
WHERE 
    s1.SID = s2.SID 
    AND p.PID = s2.PID 
GROUP BY 
    s1.SID, s1.sName
HAVING 
    COUNT(*)>1
ORDER BY 
    s1.SID, s1.sName

请帮我更正这个查询。先感谢您

4

4 回答 4

2

这正是您所要求的：

SELECT
   S.SupplierID,
   S.sName
FROM
   dbo.Suppliers S
WHERE
   EXISTS (
      SELECT *
      FROM dbo.SPJ SPJ
      WHERE S.SupplierID = SPJ.SupplierID
      GROUP BY SPJ.PartID
      HAVING Count(*) >= 2
   );

请参阅我的 SQLFiddle以在真实数据集上进行尝试。请注意，还有一个查询显示参与使供应商符合条件的所有单独行（请参见Qualifies列）。这是安装脚本的预览：

CREATE TABLE dbo.Suppliers (
   SupplierID smallint identity(1,1) NOT NULL CONSTRAINT PK_Suppliers PRIMARY KEY CLUSTERED,
   sName varchar(40) NOT NULL CONSTRAINT UQ_Suppliers_sName UNIQUE
);

CREATE TABLE dbo.Parts (
   PartID int identity(1,1) NOT NULL CONSTRAINT PK_Parts PRIMARY KEY CLUSTERED,
   pName varchar(100) NOT NULL CONSTRAINT UQ_Parts_pName UNIQUE
);

CREATE TABLE dbo.Projects (
   ProjectID int identity(1,1) NOT NULL CONSTRAINT PK_Projects PRIMARY KEY CLUSTERED,
   jName varchar(50) NOT NULL CONSTRAINT UQ_Projects_jName UNIQUE
);

CREATE TABLE dbo.SPJ (
   SupplierID smallint NOT NULL CONSTRAINT FK_SPJ_Suppliers FOREIGN KEY REFERENCES dbo.Suppliers (SupplierID),
   PartID int NOT NULL CONSTRAINT FK_SPJ_Parts FOREIGN KEY REFERENCES dbo.Parts (PartID),
   ProjectID int NOT NULL CONSTRAINT FK_SPJ_Projects FOREIGN KEY REFERENCES dbo.Projects (ProjectID),
   CONSTRAINT PK_SPJ PRIMARY KEY CLUSTERED (SupplierID, PartID, ProjectID)
);

INSERT dbo.Suppliers
VALUES
   ('Joe'' Specialty Goods'),
   ('Major Supplier'),
   ('Small Supplier'),
   ('Tamandua Manufacturing, Ltd.'),
   ('Things ''n'' Stuff'),
   ('Stuff ''n'' Things');

INSERT dbo.Parts
VALUES
   ('Watchamacallit'),
   ('Thingamajiggy'),
   ('Thingamabob'),
   ('Doohickey'),
   ('Whatsisname'),
   ('Thingy'),
   ('Gizmo'),
   ('Gadget'),
   ('Widget'),
   ('Titanium Widget'),
   ('Electronic Thingamabob'),
   ('One-Product Patrick');

INSERT dbo.Projects
VALUES
   ('Video Game Manufacturing'),
   ('Autodoc Research'),
   ('Consumer Electronics Expansion'),
   ('Space Shuttle'),
   ('Tablet Project Cobalt');

INSERT dbo.SPJ
VALUES
   (1, 2, 1),
   (1, 3, 1),
   (1, 7, 1),
   (1, 11, 1),
   (2, 1, 1),
   (2, 1, 2),
   (2, 1, 3),
   (2, 1, 4),
   (2, 2, 1),
   (2, 2, 2),
   (2, 2, 3),
   (2, 2, 4),
   (2, 2, 5),
   (2, 10, 1),
   (2, 10, 2),
   (2, 10, 3),
   (2, 10, 4),
   (2, 10, 5),
   (3, 5, 4),
   (4, 4, 2),
   (4, 4, 3),
   (5, 9, 1),
   (5, 8, 2),
   (5, 7, 3),
   (5, 6, 4),
   (5, 5, 5),
   (6, 1, 1),
   (6, 2, 1),
   (6, 3, 1),
   (6, 4, 1),
   (6, 5, 1),
   (6, 6, 1),
   (6, 7, 1),
   (6, 8, 1),
   (6, 9, 1),
   (6, 10, 1),
   (6, 11, 1);
于 2012-12-08T19:25:47.240 回答
0

你也可以这样做：

SELECT DISTINCT
a.SupplierID,
b.sName
FROM
(
  SELECT
   SupplierID,
   PartID,
   NumProjects = count(DISTINCT ProjectID)
  FROM SPJ
  GROUP BY
   SupplierID, PartID
  HAVING 
   count(DISTINCT ProjectID) >= 2 
) a
INNER JOIN Suppliers b ON a.SupplierID = b.SupplierID
于 2012-12-09T22:27:43.713 回答
0 
SELECT SID, PID, COUNT(JID)
FROM SPJ
GROUP BY SID, PID
HAVING COUNT(JID) > 1
于 2012-12-08T03:21:15.783 回答
-1 
SELECT Supplier.SID,Supplier.sName
FROM SPJ inner join Supplier on SPJ.SID = Supplier.SID
inner join Parts on SPJ.PID = Parts.PID
GROUP BY Supplier.SID,Supplier.sName
HAVING COUNT(JID) > 1
于 2012-12-08T05:12:07.243 回答