 # 1. 計算一年有多少天 ## 1.1. Oracle sql語句實例 ```sql select 'Days ...
1. 計算一年有多少天
1.1. Oracle sql語句實例
select 'Days in 2005: '||
to_char(add_months(trunc(sysdate,'y'),12)-1,'DDD')
as report
from dual
union all
select 'Days in 2004: '||
to_char(add_months(trunc(
to_date('01-SEP-2004'),'y'),12)-1,'DDD')
from dual
REPORT
-----------------
Days in 2005: 365
Days in 2004: 366
2. 查找含有數字和字母的字元串
2.1. Oracle sql語句實例
with v as (
select 'ClassSummary' strings from dual union
select '3453430278' from dual union
select 'findRow 55' from dual union
select '1010 switch' from dual union
select '333' from dual union
select 'threes' from dual
)
select strings
from (
select strings,
translate(
strings,
'abcdefghijklmnopqrstuvwxyz0123456789',
rpad('#',26,'#')||rpad('*',10,'*')) translated
from v
) x
where instr(translated,'#') ＞ 0
and instr(translated,'*') ＞ 0
3. 把整數轉換成二進位
3.1. sql Oracle語句實例
ENAME SAL SAL_BINARY
---------- ----- --------------------
SMITH 800 1100100000
ALLEN 1600 11001000000
WARD 1250 10011100010
JONES 2975 101110011111
MARTIN 1250 10011100010
BLAKE 2850 101100100010
CLARK 2450 100110010010
SCOTT 3000 101110111000
KING 5000 1001110001000
TURNER 1500 10111011100
ADAMS 1100 10001001100
JAMES 950 1110110110
FORD 3000 101110111000
MILLER 1300 10100010100
3.2. sql語句實例
select ename,
sal,
(
select bin
from dual
model
dimension by ( 0 attr )
measures ( sal num,
cast(null as varchar2(30)) bin,
'0123456789ABCDEF' hex
)
rules iterate (10000) until (num[0] ＜= 0) (
bin[0] = substr(hex[cv()],mod(num[cv()],2)+1,1)||bin[cv()],
num[0] = trunc(num[cv()]/2)
)
) sal_binary
from emp
4. 標量子查詢轉換為複合子查詢
4.1. sql語句實例
select e.deptno,
e.ename,
e.sal,
(select d.dname,d.loc,sysdate today
from dept d
where e.deptno=d.deptno)
from emp e
4.2. SELECT列表裡的子查詢只允許返回一個值
4.3. sql語句實例
create type generic_obj
as object (
val1 varchar2(10),
val2 varchar2(10),
val3 date
);
4.3.1. 對象類型
4.4. sql語句實例
select x.deptno,
x.ename,
x.multival.val1 dname,
x.multival.val2 loc,
x.multival.val3 today
from (
select e.deptno,
e.ename,
e.sal,
(select generic_obj(d.dname,d.loc,sysdate+1)
from dept d
where e.deptno=d.deptno) multival
from emp e
) x
DEPTNO ENAME DNAME LOC TODAY
------ ---------- ---------- ---------- -----------
20 SMITH RESEARCH DALLAS 12-SEP-2005
30 ALLEN SALES CHICAGO 12-SEP-2005
30 WARD SALES CHICAGO 12-SEP-2005
20 JONES RESEARCH DALLAS 12-SEP-2005
30 MARTIN SALES CHICAGO 12-SEP-2005
30 BLAKE SALES CHICAGO 12-SEP-2005
10 CLARK ACCOUNTING NEW YORK 12-SEP-2005
20 SCOTT RESEARCH DALLAS 12-SEP-2005
10 KING ACCOUNTING NEW YORK 12-SEP-2005
30 TURNER SALES CHICAGO 12-SEP-2005
20 ADAMS RESEARCH DALLAS 12-SEP-2005
30 JAMES SALES CHICAGO 12-SEP-2005
20 FORD RESEARCH DALLAS 12-SEP-2005
10 MILLER ACCOUNTING NEW YORK 12-SEP-2005
4.5. 對象本身是一個標量值，它並不會違反標量子查詢的規則
5. 解析串列化的數據
5.1. sql語句實例
STRINGS
-----------------------------------
entry:stewiegriffin:lois:brian:
entry:moe::sizlack:
entry:petergriffin:meg:chris:
entry:willie:
entry:quagmire:mayorwest:cleveland:
entry:::flanders:
Entry:robo:tchi:ken:
5.1.1. sql語句實例
create view V
as
select 'entry:stewiegriffin:lois:brian:' strings
from dual
union all
select 'entry:moe::sizlack:'
from dual
union all
select 'entry:petergriffin:meg:chris:'
from dual
union all
select 'entry:willie:'
from dual
union all
select 'entry:quagmire:mayorwest:cleveland:'
from dual
union all
select 'entry:::flanders:'
from dual
union all
select 'entry:robo:tchi:ken:'
from dual
5.2. sql語句實例
VAL1 VAL2 VAL3
--------------- --------------- ---------------
moe sizlack
petergriffin meg chris
quagmire mayorwest cleveland
robo tchi ken
stewiegriffin lois brian
willie
flanders
5.2.1. sql語句實例
with cartesian as (
select level id
from dual
connect by level ＜= 100
)
select max(decode(id,1,substr(strings,p1+1,p2-1))) val1,
max(decode(id,2,substr(strings,p1+1,p2-1))) val2,
max(decode(id,3,substr(strings,p1+1,p2-1))) val3
from (
select v.strings,
c.id,
instr(v.strings,':',1,c.id) p1,
instr(v.strings,':',1,c.id+1)-instr(v.strings,':',1,c.id) p2
from v, cartesian c
where c.id ＜= (length(v.strings)-length(replace(v.strings,':')))-1
)
group by strings
order by 1
6. 計算比重
6.1. Oracle支持內置函數RATIO_TO_REPORT
6.2. sql語句實例
select job,num_emps,sum(round(pct)) pct_of_all_salaries
from (
select job,
count(*)over(partition by job) num_emps,
ratio_to_report(sal)over()*100 pct
from emp
)
group by job,num_emps
7. 正則表達式功能
7.1. Oracle Database 10g
7.2. sql語句實例
select emp_id, text
from employee_comment
where regexp_like(text, '[0-9]{3}[-. ][0-9]{3}[-. ][0-9]{4}')
and regexp_like(
regexp_replace(text,
'[0-9]{3}([-. ])[0-9]{3}\1[0-9]{4}',''),
'[0-9]{3}[-. ][0-9]{3}[-. ][0-9]{4}')
EMP_ID TEXT
---------- ----------------------------------------------------------
7369 126 Varnum, Edmore MI 48829, 989 313-5351
7844 989-387.5359
9999 906-387-1698, 313-535.8886
