找出重复值的SQL语句

如:venderno 有重复的列表,这里只指定了一天.
语句如下
select venderno from po where pdate='2003-9-3' group by venderno having count(*) >=2

进一步应用

SELECT vno,shortname FROM vendor WHERE vno in(select venderno from po where pdate='2003-9-3' group by venderno having count(*) >=2)

表的脚本如下:

CREATE TABLE [dbo].[po] (
  [pno] varchar(12) COLLATE Chinese_PRC_CI_AS NOT NULL,
  [pdate] smalldatetime,
  [venderno] varchar(6) COLLATE Chinese_PRC_CI_AS,
  [vender] varchar(30) COLLATE Chinese_PRC_CI_AS,
  [payment] varchar(10) COLLATE Chinese_PRC_CI_AS,
  [shipaddress] varchar(40) COLLATE Chinese_PRC_CI_AS,
  [currency] varchar(10) COLLATE Chinese_PRC_CI_AS,
  [amount] float,
  [rate] float,
  [rmbamount] float,
  [remark] varchar(10) COLLATE Chinese_PRC_CI_AS,
  [indate] smalldatetime,
  [inuser] varchar(10) COLLATE Chinese_PRC_CI_AS,
  [zldno] varchar(10) COLLATE Chinese_PRC_CI_AS,
  [cuspo] varchar(20) COLLATE Chinese_PRC_CI_AS,
  [itemno] varchar(20) COLLATE Chinese_PRC_CI_AS,
  [unicheck] smallint,
  [vendorcheck] smallint,
  [vendordate] smalldatetime,
  ON UPDATE CASCADE
  ON DELETE NO ACTION
)
ON [PRIMARY]
GO