Sql：从两个表中选择数据而不重复第一个表值？

Question

CREATE TABLE [dbo].[test](
[id] [bigint] IDENTITY(1,1) NOT NULL, 
[ctext] [varchar](12) NOT NULL, 
CONSTRAINT [PK_test] PRIMARY KEY CLUSTERED 
(
[id] ASC 
)) 

CREATE TABLE [dbo].[Comments](
[id] [bigint] IDENTITY(1,1) NOT NULL, 
[cComments] [varchar](250) NOT NULL, 
[fk_test] [bigint] NOT NULL) 
GO 

ALTER TABLE [dbo].[Comments] WITH CHECK ADD CONSTRAINT [FK_Comments_test] FOREIGN KEY([fk_test]) 
REFERENCES [dbo].[test] ([id]) 
ON DELETE CASCADE 

两个表与一个正常的一对多关系链接。

我想选择返回一个列表的列表：

----------------------------------------------------- 
|test.id|test.cnumber|comments.id|comments.cComments| 
|-------|------------|-----------|------------------| 
| 1  | mytest1 |  1  | comment1  | 
|  |   |  2  | comment2  | 
|  |   |  3  | comment3  | 
|  |   |  4  | comment4  | 
|  |   |  5  | comment5  | 
|  |   |  6  | comment6  | 
| 2  | mytest2 |  7  | comment7  | 
|  |   |  8  | comment8  | 
| 3  | mytest3 |  7  | comment9  | 
----------------------------------------------------- 

反正是有办呢？

即时通讯尝试用sql存储过程替代linq。

Answer 1

尝试这种解决方案 -

DECLARE @test TABLE 
(
    [id] [bigint] IDENTITY(1,1) NOT NULL 
, [ctext] [varchar](12) NOT NULL 
) 

DECLARE @Comments TABLE 
(
[id] [bigint] IDENTITY(1,1) NOT NULL, 
[cComments] [varchar](250) NOT NULL, 
[fk_test] [bigint] NOT NULL 
) 


INSERT INTO @test (ctext) 
VALUES ('1'), ('2') 

INSERT INTO @Comments (cComments, fk_test) 
VALUES ('123', 1), ('123', 1), ('123', 2), ('123', 2) 

SELECT id = CASE WHEN d.rcount = 1 THEN d.id END 
, cnumber = CASE WHEN d.rcount = 1 THEN d.cnumber END 
, d.commentid 
, d.cComments 
FROM (
SELECT 
    t.id 
, cnumber = t.ctext 
, commentid = c.id 
, c.cComments 
, rcount = ROW_NUMBER() OVER (PARTITION BY t.[id] ORDER BY t.[id] DESC) 
FROM @test t 
JOIN @Comments c ON t.id = c.fk_test 
) d