【转帖】SQL Oracle删除重复记录
1.Oracle删除重复记录.
删除表中多余的重复记录，重复记录是根据单个字段（peopleId）来判断，只留有rowid最小的记录.
delete from people
where peopleId in (select peopleId from people group by peopleId having count(peopleId) > 1)
and rowid not in (select min(rowid) from people group by peopleId having count(peopleId )>1)
删除表中多余的重复记录（多个字段），只留有rowid最小的记录
delete from vitae a
where (a.peopleId,a.seq) in (select peopleId,seq from vitae group by peopleId,seq having count(*) > 1)
and rowid not in (select min(rowid) from vitae group by peopleId,seq having count(*)>1)
================================
此方法可以适用于sql ,oracle
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
/*
DECLARE @count INT
SELECT @count = COUNT(*) from [table1] WHERE [column1] = 1
DELETE TOP (@count-1) from [table1] WHERE [column1] = 1 这个top后面一定要有括号
*/
fetch cur_rows into @id,@max
end
close cur_rows
set rowcount 0
=======================================
select distinct * into #Tmp from tableName
drop table tableName
select * into tableName from #Tmp
drop table #Tmp
select identity(int,1,1) as autoID, * into #Tmp from tableName
select min(autoID) as autoID into #Tmp2 from #Tmp group by Name,autoID
select * from #Tmp where autoID in(select autoID from #tmp2)
=======================================
select identity(int,1,1) as id ,name,state into #tempTable from a
delete from a
delete from #tempTable
where id not in
(
select min(id) from #tempTable group by name
)
insert into a( name,state)
select name,state from #tempTable
drop table #tempTable
本文来自CSDN博客，出处：http://b
相关文档：
set ANSI_NULLS ON
set QUOTED_IDENTIFIER ON
Go
----截取字符串，并出去html
create FUNCTION [dbo].[CutString] (@str varchar(1000),@length int)
RETURNS varchar(1000) AS
BEGIN
declare @mainstr varchar(1000)
declare @substr varchar(1000)
if(@str is not null or @st ......
设计原则
符号三大范式（每一列表达一个意思，每一行代表一个实例/每一行有唯一键/表内没有其它表的非主键信息）
每个表应该有的3个有用字段（记录创建或更新时间/记录创建者/记录版本）
避免保留字
表应避免可为空的列
命名规范
表
表名如Or ......
PL/SQL DEVELOPER 基本用法详解(建议写过第一个存储过程后的初手必读)
用过oracle的都抱怨，为了稳定 它提供的图形化操作 速度慢的让人伤心呀，p4+128M的机器只要启动一个
oracle服务就够让人伤心的，再在dba studio里面操作真能让人哭。
pl/sql developer正是解决这个问题� ......
第一阶段
Q.编写一个PL/SQL程序块以显示所给出雇员编号的雇员的详细信息。
A.
DECLARE
erec emp%ROWTYPE;
BEGIN
SELECT * INTO erec from emp WHERE empno=&雇员编号;
DBMS_OUTPUT.PUT_LINE('EmpNo' || ' ' || 'Ename' || ' '|| 'Job' || ' ' || 'Manager' || ' ' || 'HireDate' ......
