MSSqlServer伪序列_MySQL

MSSqlServer伪序列_MySQL

先创建一个序列表
if exists (select 1
from sysindexeswhere 
id = object_id('TSysSequence')and 
name = 'In_SeName'and indid > 0and indid < 255)drop 
index TSysSequence.In_SeNamegoif exists 
(select 1from sysobjectswhere id = object_id('TSysSequence')and type = 'U')drop table TSysSequencego
/*======================================*//* Table: TSysSequence *//*=======================================*/
create table TSysSequence (SeName nvarchar(50) not null,
Increment int not null default 1,CurVal bigint not null default 0)goif exists 
(select 1 from sys.extended_propertieswhere major_id = object_id('TSysSequence') 
and minor_id = 0)begindeclare @CurrentUser sysnameselect @CurrentUser = user_name()execute 
sp_dropextendedproperty 'MS_Description','user', @CurrentUser, 'table', 'TSysSequence'endselect 
@CurrentUser = user_name()execute sp_addextendedproperty 'MS_Description','

模拟oracle序列

不允许用户维护，数据库初始化以后不允许任何人修改其中的值。

默认生成名称为“DID”和“SID”的两个序列，意义为“数据序列号”和“系统序列号”。',

'user', @CurrentUser, 'table', 'TSysSequence'goinsert into TSysSequence (SeName,Increment,CurVal) 
values ('DID',1,0) ;insert into TSysSequence (SeName,Increment,CurVal) values ('SID',1,0) ;
/*=======================================*//* Index: In_SeName *//*=======================================*/
create unique index In_SeName on TSysSequence (SeName ASC)
go

再创建一个存储过程完成序列的使用

if exists (select 1from sysobjectswhere id = object_id('PGetSequenceValue')and type in ('P','PC'))drop 
procedure PGetSequenceValuegocreate 
procedure PGetSequenceValue@SeName nvarchar(50),@SeVal bigint 
outasbeginif not 
exists(select 1 from TSysSequence where SeName = @SeName)
beginraiserror('不存在序列%s',16,1,@SeName)returnend
update TSysSequence set @SeVal = CurVal + Increment, 
CurVal = CurVal + Increment where SeName = @SeNameendgo

使用方法

declare @ID1 intEXEC PGetSequenceValue 'SID',@ID1 OUTPUT
select @ID1
declare @ID2 intEXEC PGetSequenceValue 'DID',@ID2 OUTPUT
select @ID2

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