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)

我在大多数SQL DB上创建了一个函数来实现这一点。

CREATE OR ALTER FUNCTION [dbo].[UTIL_SplitList](@parList Varchar(MAX),@splitChar Varchar(1)=',') 
  Returns @t table (Column_Value varchar(MAX))
  as
  Begin
    Declare @pos integer 
    set @pos = CharIndex(@splitChar, @parList)
    while @pos > 0
    Begin
      Insert Into @t (Column_Value) VALUES (Left(@parList, @pos-1))
      set @parList = Right(@parList, Len(@parList) - @pos)
      set @pos = CharIndex(@splitChar, @parList)
    End
    Insert Into @t (Column_Value) VALUES (@parList)
    Return
  End

一旦函数存在，它就非常简单

SELECT DISTINCT 
    *
FROM 
    [dbo].[UTIL_SplitList]('1,1,1,2,5,1,6',',') 

这样的行构造函数只能在SQL Server 2008及以上版本上使用: 你可以用

SELECT DISTINCT *
FROM (
  VALUES (1), (1), (1), (2), (5), (1), (6)
) AS X(a)

有关更多信息，请参阅:

官方的女士 http://www.sql-server-helper.com/sql-server-2008/row-value-constructor-as-derived-table.aspx

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);

总的来说:

SELECT 
  DISTINCT 
      FieldName1, FieldName2, ..., FieldNameN
FROM
  (
    Values
        ( ValueForField1, ValueForField2,..., ValueForFieldN ),
        ( ValueForField1, ValueForField2,..., ValueForFieldN ),
        ( ValueForField1, ValueForField2,..., ValueForFieldN ),
        ( ValueForField1, ValueForField2,..., ValueForFieldN ),
        ( ValueForField1, ValueForField2,..., ValueForFieldN )
  ) AS TempTableName ( FieldName1, FieldName2, ..., FieldNameN )

在你的情况下:

Select 
  distinct
  TempTableName.Field1 
From 
  (
  VALUES
    (1), 
    (1), 
    (1), 
    (2), 
    (5), 
    (1), 
    (6)
  ) AS TempTableName (Field1)