Question

This is my table:

CREATE TABLE [Test].[dbo].[MyTest]
(
[Id]    BIGINT NOT NULL,
[FId]   BIGINT NOT NULL,
[SId]   BIGINT NOT NULL
);

And some data:

INSERT INTO  [Test].[dbo].[MyTest] ([Id], [FId], [SId]) VALUES (1, 100, 11); 
INSERT INTO  [Test].[dbo].[MyTest] ([Id], [FId], [SId]) VALUES (2, 200, 12); 
INSERT INTO  [Test].[dbo].[MyTest] ([Id], [FId], [SId]) VALUES (3, 100, 21); 
INSERT INTO  [Test].[dbo].[MyTest] ([Id], [FId], [SId]) VALUES (4, 200, 22);
INSERT INTO  [Test].[dbo].[MyTest] ([Id], [FId], [SId]) VALUES (5, 300, 13); 
INSERT INTO  [Test].[dbo].[MyTest] ([Id], [FId], [SId]) VALUES (6, 200, 12); 

So I need 2 select query,

First Select FId, SId that like a distinct in both column so the result is:

100, 11
200, 12
100, 21
200, 22
300, 13

As you see the values of 200, 12 returned once.

Second query is the Id’s of that columns whose duplicated in both FId, SId So the result is:

2
6

Does any one have any idea about it?

Answer 1

First query:

SELECT DISTINCT Fid,SId 
FROM MyTest

Second query:

SELECT DISTINCT a1.Id
FROM MyTest a1 INNER JOIN MyTest a2
    ON a1.Fid = a2.Fid 
   AND a1.SId = a2.SId
   AND a1.Id <> a2.Id

I cannot test them, but I think they should work…