使用GROUP BY可以提供比DISTINCT更好的性能:

SELECT *
FROM
(
    VALUES
        (1),
        (1),
        (1),
        (2),
        (5),
        (1),
        (6)
) AS A (nums)
GROUP BY A.nums;

PostgreSQL提供了两种方法:

SELECT DISTINCT * FROM (VALUES('a'),('b'),('a'),('v')) AS tbl(col1)

or

SELECT DISTINCT * FROM (select unnest(array['a','b', 'a','v'])) AS tbl(col1)

使用数组方法，你也可以这样做:

SELECT DISTINCT * FROM (select unnest(string_to_array('a;b;c;d;e;f;a;b;d', ';'))) AS tbl(col1)

这适用于SQL Server 2005，如果有最大数量:

SELECT * 
FROM
  (SELECT ROW_NUMBER() OVER(ORDER BY a.id) NUMBER
  FROM syscomments a
  CROSS JOIN syscomments b) c
WHERE c.NUMBER IN (1,4,6,7,9)

如果你需要一个数组，用逗号分隔数组列:

SELECT * FROM (VALUES('WOMENS'),('MENS'),('CHILDRENS')) as X([Attribute])
,(VALUES(742),(318)) AS z([StoreID])

如果它是一个来自现有SQL表的参数列表，例如来自现有Table1的ID列表，那么你可以尝试这样做:

select distinct ID
      FROM Table1
      where 
      ID in (1, 1, 1, 2, 5, 1, 6)
ORDER BY ID;

或者，如果你需要参数列表作为一个SQL表常量(变量)，试试这个:

WITH Id_list AS (
     select ID
      FROM Table1
      where 
      ID in (1, 1, 1, 2, 5, 1, 6)
)
SELECT distinct * FROM Id_list
ORDER BY ID;

你可以使用的另一种方式是这样的查询:

SELECT DISTINCT
    LTRIM(m.n.value('.[1]','varchar(8000)')) as columnName
FROM 
    (SELECT CAST('<XMLRoot><RowData>' + REPLACE(t.val,',','</RowData><RowData>') + '</RowData></XMLRoot>' AS XML) AS x
     FROM (SELECT '1, 1, 1, 2, 5, 1, 6') AS t(val)
    ) dt
  CROSS APPLY 
    x.nodes('/XMLRoot/RowData') m(n);