requête pour obtenir uniquement les données en double

Question

J'ai une table avec des données

    ID  Name 

        1  John 
        2  Robert 
        3  John 
        4  Sam 
        5  Jack 
        6  Sam 

     Now i want ony the the duplicate names ony through query 

     ie.., 

        Name 

        John 
        Sam 

Answer 1

SELECT Name 
FROM YourTable 
GROUP BY Name 
HAVING COUNT(*) > 1 

Answer 2

CREATE TABLE MyTable (
    ID int 
    , Name nvarchar(50) 
) 

INSERT MyTable VALUES (1, 'John') 
INSERT MyTable VALUES (2, 'Robert') 
INSERT MyTable VALUES (3, 'John') 
INSERT MyTable VALUES (4, 'Sam') 
INSERT MyTable VALUES (5, 'Jack') 
INSERT MyTable VALUES (6, 'Sam') 

SELECT 
    Name 
FROM 
    MyTable 
GROUP BY 
    Name 
HAVING 
    COUNT(*) > 1 

DROP TABLE MyTable 

Résultats:

Name 
-------------------------------------------------- 
John 
Sam 

Answer 3

with temp as (
    select Name, count(Name) as countOfNames 
    from myTable 
    group by Name 
    ) 
select Name from temp 
where countOfNames > 1 

Answer 4

select columnname,count(column name) from tablename group by column name having count(*)>1