数据库Oracle与SqlServer与Access

1,时间: Access:now() SqlServer:getdate() oracle:sysdate() 2,游标： sqlserver: declare @id int declare rs cursor for select PdaId from Biz_Pda where PdaState = ' 1 ' or PdaState = ' 2 ' if @iPda = 1 begin open rs fetch next from rs into @id

declare @id int
declare rs cursor for select PdaId from Biz_Pda where PdaState='1' or PdaState='2'
if @iPda=1
begin
open rs
fetch next from rs
into @id
while @@fetch_status=0
begin
--执行的操作
end
close rs
deallocate rs
end

declare
r_cert certrecord%rowtype;
cursor cs is select * from certrecord order by id;
begin
open cs;
loop
fetch cs into r_cert;
exit when cs%notfound;--没有数据退出
--执行的操作
end loop;
commit;--提交数据
close cs;
end;

select @parameter=t.aa from table

select t.aa into parameter from table

4,函数：

字符转换：

sqlserver:str(..)

oracle:to_char(..)

access:cstr(..)

字符截取：([]为可选)

sqlserver:substring(s,start,length)

oracle:substr(s,start[,length])

access:Mid(s,start[,length])

注：sqlserver和oracle中start可从0或1开始，二者结果是一样的，access只能从1开始

5,case

在oracle,sqlserver都有case语句：

oracle:

Code
select c.userid,
a.unitcode,a.crid,a.isck,a.iszk,a.iszt,a.iszh,a.iswbz,
(case
when (select t.rylx from t_caijirecord t where t.crid=a.crid)=0 then 1
else 0
end) iscjk,
(case
when (select t.rylx from t_caijirecord t where t.crid=a.crid)=1 then 1
else 0
end) isczk,
c.idcardnum,c.receivetime
from certrecord c inner join
a_certrecord a on c.id = a.crid

SqlServer
SELECT
UserPassportID as PassportID,
UserID,
GrantorID,
Case ObjectTypeID
When 1 then ObjectID
End
as TerminalID,
Type, Flag, GrantDate, Validate, Invalidate
From UserPassport

Access:

Access
select OperationNo,iif(IsMadeFile=1,'sended',iif(IsMadeFile=0,'nosend')) as IsSend from T_OperationHistory
select OperationNo,switch(IsMadeFile=1,'sended',IsMadeFile=0,'nosend') as IsSend from T_OperationHistory