方法一
第一步：查询重复记录
SELECT * FROM TableName --表名
WHERE RepeatFiled IN (
SELECT RepeatFiled --重复字段
FROM TableName
GROUP BY RepeatFiled
HAVING COUNT(RepeatFiled) > 1
) 把重复条数大于1的全部查询出来。
第二步：删除重复记录，只保留一条
SELECT * FROM TableName
WHERE RepeatFiled IN (
SELECT RepeatFiled
FROM TableName
GROUP BY RepeatFiled
HAVING COUNT(RepeatFiled) > 1
AND
ID NOT IN (
SELECT MIN(ID)
FROM TableName
GROUP RepeatFiled
HAVING COUNT(RepeatFiled) > 1
)
) 在第一步的基础上继续过滤，把最小值留下。
方法二
declare @max integer,@id integer
declare cur_rows cursor local for select 主字段,count(*) from 表名 group by 主字段 having count(*) >； 1
open cur_rows
fetch cur_rows into @id,@max
while @@fetch_status=0
begin
select @max = @max -1
set rowcount @max
delete from 表名 where 主字段 = @id
fetch cur_rows into @id,@max
end
close cur_rows
set rowcount 0
