1. SQL里邊的求和語句怎麼寫
用select sum(列名),sum(列名),sum(列名)…… from 表 where 條件。
2. SQL Select 語句的用法
以下是代碼片段：
SQL:
select
*
into
b
from
a
where
1<>1說明：拷貝表(拷貝數據,源表名：a
目標表名：b)以下是代碼片段：
SQL:
insert
into
b(a,
b,
c)
select
d,e,f
from
b;說明：顯示文章、提交人和最後回復時間以下是代碼片段：
SQL:
select
a.title,a.username,b.adddate
from
table
a,(select
max(adddate)
adddate
from
table
where
table.title=a.title)
b說明：外連接查詢(表名1：a
表名2：b)以下是代碼片段：
SQL:
select
a.a,
a.b,
a.c,
b.c,
b.d,
b.f
from
a
LEFT
OUT
JOIN
b
ON
a.a
=
b.c說明：日程安排提前五分鍾提醒以下是代碼片段：
SQL:
select
*
from
日程安排
where
datediff(』minute』,f開始時間,getdate())>5
說明：兩張關聯表，刪除主表中已經在副表中沒有的信息
SQL:
以下是代碼片段：
delete
from
info
where
not
exists
(
select
*
from
infobz
where
info.infid=infobz.infid 說明：--
SQL:
以下是代碼片段：
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:
以下是代碼片段：
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,高考總成績說明：
從資料庫中去一年的各單位電話費統計(電話費定額賀電化肥清單兩個表來源）
SQL:
以下是代碼片段：
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』)說明：四表聯查問題：SQL:
以下是代碼片段：
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
.....說明：得到表中最小的未使用的ID號
SQL:
以下是代碼片段：
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)