1.說明：複製表(只複製結構,源表名：a 新錶名：b)
sql: select * into b from a where 1<>1
2.說明：拷貝表(拷貝資料,源表名：a 目標表名：b)
sql: insert into b(a, b, c) select d,e,f from a;
sql: select a.title,a.username,b.adddate from table a,(select max(adddate) adddate from table where table.title=a.title) b
4.說明：外連線查詢(表名1：a 表名2：b)
sql: select a.a, a.b, a.c, b.c, b.d, b.f from a left outer join b on a.a = b.c
sql: select * from 日程安排 where datediff('minute',f開始時間,getdate())>5
6.說明：兩張關聯表，刪除主表中已經在副表中沒有的資訊
sql:
delete from info where not exists ( select * from infobz where info.infid=infobz.infid )
說明：--
sql:
select a.num, a.name, b.upd_date, b.prev_upd_date
from table1,
(select x.num, x.upd_date, y.upd_date prev_upd_date
from (select num, upd_date, inbound_qty, stock_onhand
from table2
where to_char(upd_date,'yyyy/mm') = to_char(sysdate, 'yyyy/mm')) x,
(select num, upd_date, stock_onhand
from table2
where to_char(upd_date,'yyyy/mm') =
to_char(to_date(to_char(sysdate, 'yyyy/mm') || '/01','yyyy/mm/dd') - 1, 'yyyy/mm') ) y,
where x.num = y.num （+）
and x.inbound_qty + nvl(y.stock_onhand,0) <> x.stock_onhand ) b
where a.num = b.num
說明：--
sql:
select * from studentinfo where not exists(select * from student where studentinfo.id=student.id) and 系名稱='"&strdepartmentname&"' and 專業名稱='"&strprofessionname&"' order by 性別,生源地,高考總成績
7.說明：
從資料庫中去一年的各單位**費統計(**費定額賀電化肥清單兩個表**）
sql:
select a.userper, a.tel, a.standfee, to_char(a.telfeedate, 'yyyy') as telyear,
sum(decode(to_char(a.telfeedate, 'mm'), '01', a.factration)) as jan,
sum(decode(to_char(a.telfeedate, 'mm'), '02', a.factration)) as fri,
sum(decode(to_char(a.telfeedate, 'mm'), '03', a.factration)) as mar,
sum(decode(to_char(a.telfeedate, 'mm'), '04', a.factration)) as apr,
sum(decode(to_char(a.telfeedate, 'mm'), '05', a.factration)) as may,
sum(decode(to_char(a.telfeedate, 'mm'), '06', a.factration)) as jue,
sum(decode(to_char(a.telfeedate, 'mm'), '07', a.factration)) as jul,
sum(decode(to_char(a.telfeedate, 'mm'), '08', a.factration)) as agu,
sum(decode(to_char(a.telfeedate, 'mm'), '09', a.factration)) as sep,
sum(decode(to_char(a.telfeedate, 'mm'), '10', a.factration)) as oct,
sum(decode(to_char(a.telfeedate, 'mm'), '11', a.factration)) as nov,
sum(decode(to_char(a.telfeedate, 'mm'), '12', a.factration)) as dec
from (select a.userper, a.tel, a.standfee, b.telfeedate, b.factration
from telfeestand a, telfee b
where a.tel = b.telfax) a
group by a.userper, a.tel, a.standfee, to_char(a.telfeedate, 'yyyy')
8.說明：四表聯查問題：
sql: select * from a left inner join b on a.a=b.b right inner join c on a.a=c.c inner join d on a.a=d.d where .....
9.說明：得到表中最小的未使用的id號
sql:
select (case when exists(select * from handle b where b.handleid = 1) then min(handleid) + 1 else 1 end) as handleid
from handle
where not handleid in (select a.handleid - 1 from handle a)
9.sql語句技巧
9.1、乙個sql語句的問題:行列轉換
select * from v_temp
上面的檢視結果如下:
user_name role_name
-------------------------
系統管理員 管理員
feng 管理員
feng 一般使用者
test 一般使用者
想把結果變成這樣:
user_name role_name
---------------------------
系統管理員 管理員
feng 管理員,一般使用者
test 一般使用者
***************==
== create table a_test(name varchar(20),role2 varchar(20))
insert into a_test values('李','管理員')
insert into a_test values('張','管理員')
insert into a_test values('張','一般使用者')
insert into a_test values('常','一般使用者')
create function join_str(@content varchar(100))
returns varchar(2000) as
begin
declare @str varchar(2000)
set @str=''
select @str=@str+','+rtrim(role2) from a_test where [name]=@content
select @str=right(@str,len(@str)-1)
return @str
end go
--呼叫：
select [name],dbo.join_str([name]) role2 from a_test group by [name]
--select distinct name,dbo.uf_test(name) from a_test
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