SQL内部连接客户与订单

如果我有两个表（客户之一，与他们的信息，包括地址，姓名，电子邮件等），另一个订单（以订单号，发货日期，客户名称谁下令项目），我怎么能显示少于3个订单的客户的电子邮件？SQL内部连接客户与订单

我知道我必须使用一个内连接和一些别名的，但我不知道如何着手。

谢谢！

是我到目前为止有：

SELECT customer.email 
FROM customer as cust 
INNER JOIN (select customer_id, sum(line_qty) AS total 
      from orders as o ON cust.customer_id = o.customer_id 
      where total = (SELECT total < 3 
          FROM (select customer_id, sum(line_qty) AS total 
           from orders as o ON cust.customer_id = o.customer_id 
           ) as sub);

来源

2014-12-06 Student3794

发表您的尝试。事实上，使用模式和一些示例数据创建sqlfiddle！ – 2014-12-06 02:58:15

刚刚发布了它@MitchWheat – Student3794 2014-12-06 03:41:00

你正在使用哪些DBMS？ Postgres的？甲骨文？ – 2014-12-06 06:27:20

我已经创建了SQL的完整的例子。只需运行查询即可创建数据库，表格和“获取客户订单”的存储过程。

“客户”和表格“订单”中的样本数据的关系是“1客户到很多订单”，所以客户在表格中有一个外键订单，以识别哪个客户有订单。所以。

首先创建数据库，运行此查询。

Create DataBase [Customer_OrdersDB]

刷新服务器浏览器，你会发现一个数据库的名称已经创建。然后运行查询以创建存储过程和表。

USE [Customer_OrdersDB] 
GO 
CREATE PROCEDURE [dbo].[GetCustomer_Mail] 
AS 
BEGIN 
select Email as Customer_Mail 
from Customers as cust inner join Orders as ord 
on cust.CustomerId = ord.OrderCustomerId 
group by(Email) 
having COUNT(ord.OrderCustomerId) < 3 
END 

GO 
SET ANSI_NULLS ON 
GO 
SET QUOTED_IDENTIFIER ON 
GO 
CREATE TABLE [dbo].[Customers](
    [CustomerId] [int] IDENTITY(1,1) NOT NULL, 
    [CustomerName] [nvarchar](50) NULL, 
    [Address] [nvarchar](50) NULL, 
    [Email] [nvarchar](50) NULL, 
CONSTRAINT [PK_Customers] PRIMARY KEY CLUSTERED 
(
    [CustomerId] ASC 
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY] 
) ON [PRIMARY] 

GO 
/****** Object: Table [dbo].[Orders] Script Date: 12/6/2014 5:19:11 AM ******/ 
SET ANSI_NULLS ON 
GO 
SET QUOTED_IDENTIFIER ON 
GO 
CREATE TABLE [dbo].[Orders](
    [OrderId] [int] IDENTITY(1,1) NOT NULL, 
    [OrderDate] [datetime] NULL, 
    [OrderNumber] [nvarchar](50) NULL, 
    [OrderCustomerId] [int] NULL, 
CONSTRAINT [PK_Orders] PRIMARY KEY CLUSTERED 
(
    [OrderId] ASC 
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY] 
) ON [PRIMARY] 

GO 
SET IDENTITY_INSERT [dbo].[Customers] ON 

INSERT [dbo].[Customers] ([CustomerId], [CustomerName], [Address], [Email]) VALUES (1, N'Ahmed', N'Cairo', N'[email protected]') 
INSERT [dbo].[Customers] ([CustomerId], [CustomerName], [Address], [Email]) VALUES (2, N'Ali', N'Paris', N'[email protected]') 
INSERT [dbo].[Customers] ([CustomerId], [CustomerName], [Address], [Email]) VALUES (3, N'Samir', N'UK', N'[email protected]') 
SET IDENTITY_INSERT [dbo].[Customers] OFF 
SET IDENTITY_INSERT [dbo].[Orders] ON 

INSERT [dbo].[Orders] ([OrderId], [OrderDate], [OrderNumber], [OrderCustomerId]) VALUES (1, CAST(0x0000A2A600000000 AS DateTime), N'1234', 1) 
INSERT [dbo].[Orders] ([OrderId], [OrderDate], [OrderNumber], [OrderCustomerId]) VALUES (2, CAST(0x0000A2C700000000 AS DateTime), N'555', 1) 
INSERT [dbo].[Orders] ([OrderId], [OrderDate], [OrderNumber], [OrderCustomerId]) VALUES (3, CAST(0x00009CF100000000 AS DateTime), N'56d66', 1) 
INSERT [dbo].[Orders] ([OrderId], [OrderDate], [OrderNumber], [OrderCustomerId]) VALUES (4, CAST(0x00009E9B00000000 AS DateTime), N'555we', 2) 
INSERT [dbo].[Orders] ([OrderId], [OrderDate], [OrderNumber], [OrderCustomerId]) VALUES (5, CAST(0x0000A2A600000000 AS DateTime), N'1234', 1) 
INSERT [dbo].[Orders] ([OrderId], [OrderDate], [OrderNumber], [OrderCustomerId]) VALUES (6, CAST(0x0000A2C700000000 AS DateTime), N'555', 1) 
SET IDENTITY_INSERT [dbo].[Orders] OFF 
ALTER TABLE [dbo].[Orders] WITH CHECK ADD CONSTRAINT [FK_Orders_Customers] FOREIGN KEY([OrderCustomerId]) 
REFERENCES [dbo].[Customers] ([CustomerId]) 
GO 
ALTER TABLE [dbo].[Orders] CHECK CONSTRAINT [FK_Orders_Customers] 
GO

然后访问你想要得到的客户电子邮件，如果他/她做订单少于3个数量级的存储过程。

转到SQL Server服务器/对象浏览器。
选择名称[Customer_OrdersDB]的数据库。
选择“可编程性”。
选择“StoredProcedures”。
右键单击您的存储过程“GetCustomer_Mail”，然后选择执行。

来源

2014-12-06 03:38:21

你现在怎么使用SQL Server？ – 2014-12-06 06:47:35

试试这个：

SELECT c.email 
FROM customer AS c 
LEFT OUTER JOIN orders AS o ON c.customer_id = o.customer_id 
GROUP BY c.email 
HAVING SUM(o.line_qty) < 3

来源

2014-12-06 06:14:41

SQL内部连接客户与订单

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