常见数据库对日期时间格式化

1、mysql

DATE_FORMAT(date,format)
根据format字符串格式化date值。下列修饰符可以被用在format字符串中:

%M  月名字(January……December)
%W  星期名字(Sunday……Saturday)
%D  有英语前缀的月份的日期(1st, 2nd, 3rd, 等等。)
%Y  年, 数字, 4 位
%y  年, 数字, 2 位
%a  缩写的星期名字(Sun……Sat)
%d  月份中的天数, 数字(00……31)
%e  月份中的天数, 数字(0……31)
%m  月, 数字(01……12)
%c  月, 数字(1……12)
%b  缩写的月份名字(Jan……Dec)
%j  一年中的天数(001……366)
%H  小时(00……23)
%k  小时(0……23)
%h  小时(01……12)
%I  小时(01……12)
%l  小时(1……12)
%i  分钟, 数字(00……59)
%r  时间,12 小时(hh:mm:ss [AP]M)
%T  时间,24 小时(hh:mm:ss)
%S  秒(00……59)
%s  秒(00……59)
%p  AM或PM
%w  一个星期中的天数(0=Sunday ……6=Saturday )
%U  星期(0……52), 这里星期天是星期的第一天
%u  星期(0……52), 这里星期一是星期的第一天
%%  一个文字“%”

2、sql server

sql server转换使用convert来实现


Select CONVERT(varchar(100), GETDATE(), 0): 05 16 2006 10:57AM
Select CONVERT(varchar(100), GETDATE(), 1): 05/16/06
Select CONVERT(varchar(100), GETDATE(), 2): 06.05.16
Select CONVERT(varchar(100), GETDATE(), 3): 16/05/06
Select CONVERT(varchar(100), GETDATE(), 4): 16.05.06
Select CONVERT(varchar(100), GETDATE(), 5): 16-05-06
Select CONVERT(varchar(100), GETDATE(), 6): 16 05 06
Select CONVERT(varchar(100), GETDATE(), 7): 05 16, 06
Select CONVERT(varchar(100), GETDATE(), 8 ): 10:57:46
Select CONVERT(varchar(100), GETDATE(), 9): 05 16 2006 10:57:46:827AM
Select CONVERT(varchar(100), GETDATE(), 10): 05-16-06
Select CONVERT(varchar(100), GETDATE(), 11): 06/05/16
Select CONVERT(varchar(100), GETDATE(), 12): 060516
Select CONVERT(varchar(100), GETDATE(), 13): 16 05 2006 10:57:46:937
Select CONVERT(varchar(100), GETDATE(), 14): 10:57:46:967
Select CONVERT(varchar(100), GETDATE(), 20): 2006-05-16 10:57:47
Select CONVERT(varchar(100), GETDATE(), 21): 2006-05-16 10:57:47.157
Select CONVERT(varchar(100), GETDATE(), 22): 05/16/06 10:57:47 AM
Select CONVERT(varchar(100), GETDATE(), 23): 2006-05-16
Select CONVERT(varchar(100), GETDATE(), 24): 10:57:47
Select CONVERT(varchar(100), GETDATE(), 25): 2006-05-16 10:57:47.250
Select CONVERT(varchar(100), GETDATE(), 100): 05 16 2006 10:57AM
Select CONVERT(varchar(100), GETDATE(), 101): 05/16/2006
Select CONVERT(varchar(100), GETDATE(), 102): 2006.05.16
Select CONVERT(varchar(100), GETDATE(), 103): 16/05/2006
Select CONVERT(varchar(100), GETDATE(), 104): 16.05.2006
Select CONVERT(varchar(100), GETDATE(), 105): 16-05-2006
Select CONVERT(varchar(100), GETDATE(), 106): 16 05 2006
Select CONVERT(varchar(100), GETDATE(), 107): 05 16, 2006
Select CONVERT(varchar(100), GETDATE(), 108): 10:57:49
Select CONVERT(varchar(100), GETDATE(), 109): 05 16 2006 10:57:49:437AM
Select CONVERT(varchar(100), GETDATE(), 110): 05-16-2006
Select CONVERT(varchar(100), GETDATE(), 111): 2006/05/16
Select CONVERT(varchar(100), GETDATE(), 112): 20060516
Select CONVERT(varchar(100), GETDATE(), 113): 16 05 2006 10:57:49:513
Select CONVERT(varchar(100), GETDATE(), 114): 10:57:49:547
Select CONVERT(varchar(100), GETDATE(), 120): 2006-05-16 10:57:49
Select CONVERT(varchar(100), GETDATE(), 121): 2006-05-16 10:57:49.700
Select CONVERT(varchar(100), GETDATE(), 126): 2006-05-16T10:57:49.827
Select CONVERT(varchar(100), GETDATE(), 130): 28 ????? 1431  3:26:31:180PM
Select CONVERT(varchar(100), GETDATE(), 131): 18/04/1427 10:57:49:920AM

3、oracle

oracle转换日期或者时间用to_char(datetime, format)

format的参数有

HH     一天的小时数 (01-12)
HH12     一天的小时数 (01-12)
HH24     一天的小时数 (00-23)
MI     分钟 (00-59)
SS     秒 (00-59)
SSSS     午夜后的秒 (0-86399)
AM or A.M. or PM or P.M.     正午标识(大写)
am or a.m. or pm or p.m.     正午标识(小写)
Y,YYY     带逗号的年(4 和更多位)
YYYY     年(4和更多位)
YYY     年的后三位
YY     年的后两位
Y     年的最后一位
BC or B.C. or AD or A.D.     年标识(大写)
bc or b.c. or ad or a.d.     年标识(小写)
MONTH     全长大写月份名(9字符)
Month     全长混合大小写月份名(9字符)
month     全长小写月份名(9字符)
MON     大写缩写月份名(3字符)
Mon     缩写混合大小写月份名(3字符)
mon     小写缩写月份名(3字符)
MM     月份 (01-12)
DAY     全长大写日期名(9字符)
Day     全长混合大小写日期名(9字符)
day     全长小写日期名(9字符)
DY     缩写大写日期名(3字符)
Dy     缩写混合大小写日期名(3字符)
dy     缩写小写日期名(3字符)
DDD     一年里的日子(001-366)
DD     一个月里的日子(01-31)
D     一周里的日子(1-7;SUN=1)
W     一个月里的周数
WW     一年里的周数
CC     世纪(2 位)
J     Julian 日期(自公元前4712年1月1日来的日期)
Q     季度
RM     罗马数字的月份(I-XII;I=JAN)-大写
rm     罗马数字的月份(I-XII;I=JAN)-小写

精彩SQL语句

1、oracle求每月第一天和最后一天

SELECT Trunc(Trunc(SYSDATE, 'MONTH') - 1, 'MONTH') First_Day_Last_Month,
 Trunc(SYSDATE, 'MONTH') - 1 / 86400 Last_Day_Last_Month,
 Trunc(SYSDATE, 'MONTH') First_Day_Cur_Month,
 LAST_DAY(Trunc(SYSDATE, 'MONTH')) + 1 - 1 / 86400 Last_Day_Cur_Month
FROM dual;

2、sql server对日期的常规处理

SELECT REPLACE(CONVERT(varchar(10),GETDATE(),120),N'-0','-')  短日期格式:yyyy-m-d
SELECT STUFF(STUFF(CONVERT(char(8),GETDATE(),112),5,0,N'年'),8,0,N'月')+N'日'  长日期格式:yyyy年mm月dd日 --A. 方法1
SELECT DATENAME(Year,GETDATE())+N'年'+DATENAME(Month,GETDATE())+N'月'+DATENAME(Day,GETDATE())+N'日'   长日期格式:yyyy年mm月dd日 --A. 方法2
SELECT DATENAME(Year,GETDATE())+N'年'+CAST(DATEPART(Month,GETDATE()) AS varchar)+N'月 '+DATENAME(Day,GETDATE())+N'日'  短日期格式:yyyy年m月d日
SELECT CONVERT(char(11),GETDATE(),120)+CONVERT(char(12),GETDATE(),114)  完整日期+时间格式:yyyy-mm-dd hh:mi:ss:mmm
Select CONVERT(varchar(100), GETDATE(), 8 ): 10:57:46
Select CONVERT(varchar(100), GETDATE(), 24): 10:57:47
Select CONVERT(varchar(100), GETDATE(), 108): 10:57:49
Select CONVERT(varchar(100), GETDATE(), 12): 060516
Select CONVERT(varchar(100), GETDATE(), 23): 2006-05-16 

3、oracle中400w条记录的表中随机删除20条记录

--使用for
declare 
begin
     for c in (select * from (  select rowid rd from t2  order by dbms_random.value)m where rownum<=20) 
      loop
        delete from t2 where rowid=c.rd;
      end loop;
  commit;
end;
--不使用for
declare abc number;
arid rowid;
cursor cursor_sal is
 select * from (select rowid rd from t2  order by dbms_random.value)m where rownum<=20;
begin
      open cursor_sal;
      loop
        fetch cursor_sal into arid;
         exit when cursor_sal%notfound;
        delete from t2 where rowid=arid;
      end loop;
      close cursor_sal; 
  commit;
end;

oracle常用语句

1、set timing on开启sql执行计时
2、查看granule大小(granule大小是以SGA大小由系统设定的,当SGA小于1G时,granule大小为4M,当SGA大于1G的时候granule大小为16M)
select component,granule_size from v$sga_dynamic_components;
3、启动数据库受限模式
startup restrict;
如果是open状态转换为受限模式为:
alter system enable restricted session;
授予restricted session权限给用户即可访问受限模式
4、kill session

select sid,serial#,username from v$session;
alter system kill session 'sid,serial#';

5、查看未commit的事务
select addr,status from v$transaction;

多种方式的md5加密

一、oracle实现md5加密:

CREATE OR REPLACE function fn_md5(input_string VARCHAR2) return varchar2
IS
raw_input RAW(128) := UTL_RAW.CAST_TO_RAW(input_string);
decrypted_raw RAW(2048);
error_in_input_buffer_length EXCEPTION;
BEGIN
sys.dbms_obfuscation_toolkit.MD5(input => raw_input,checksum => decrypted_raw);
return rawtohex(decrypted_raw);
END;

二、mysql实现md5加密:

select upper(md5('abc')) from cdb_settings limit 1;


注意问题:在mysql中不知道为什么使用了upper不能转化为大写,尝试了几个编码的mysql库都不行,也许是我mysql版本的问题,先记录下mysql版本

三、Sql Server 实现md5加密:

select hashbytes('MD5', 'abc');

四、C#实现md5加密:

string abc=System.Web.Security.FormsAuthentication.
HashPasswordForStoringInConfigFile("abc", "MD5") ;
 Response.Write(abc);

五、Javascript实现md5加密:

var hexcase = 0; function hex_md5(a)
{ return rstr2hex(rstr_md5(str2rstr_utf8(a))) }
function hex_hmac_md5(a, b)
{ return rstr2hex(rstr_hmac_md5(str2rstr_utf8(a), str2rstr_utf8(b))) }
 function md5_vm_test()
{ return hex_md5("abc").toLowerCase() == "900150983cd24fb0d6963f7d28e17f72" }
 function rstr_md5(a)
{ return binl2rstr(binl_md5(rstr2binl(a), a.length * 8)) }
 function rstr_hmac_md5(c, f)
{ var e = rstr2binl(c); if (e.length > 16)
{ e = binl_md5(e, c.length*8) }
 var a = Array(16), d = Array(16);
 for (var b = 0; b < 16; b++)
{ a[b] = e[b] ^ 909522486; d[b] = e[b] ^ 1549556828 }
var g = binl_md5(a.concat(rstr2binl(f)), 512 + f.length * 8);
return binl2rstr(binl_md5(d.concat(g), 512 + 128)) }
function rstr2hex(c) { try { hexcase } catch (g) { hexcase = 0 }
 var f = hexcase ? "0123456789ABCDEF" : "0123456789abcdef";
 var b = ""; var a; for (var d = 0; d < c.length; d++) { a = c.charCodeAt(d);
 b += f.charAt((a >>> 4) & 15) + f.charAt(a & 15) } return b } function str2rstr_utf8(c)
 { var b = ""; var d = -1; var a, e; while (++d < c.length)
{ a = c.charCodeAt(d); e = d + 1 < c.length ? c.charCodeAt(d + 1) : 0;
 if (55296 <= a && a <= 56319 && 56320 <= e && e <= 57343)
{ a = 65536 + ((a & 1023) << 10) + (e & 1023); d++ }
if (a <= 127) { b += String.fromCharCode(a) }
else { if (a <= 2047) { b += String.fromCharCode(192 | ((a >>> 6) & 31),
 128 | (a & 63)) } else { if (a <= 65535) { b += String.fromCharCode(224
| ((a >>> 12) & 15), 128 | ((a >>> 6) & 63), 128 | (a & 63)) }
else { if (a <= 2097151) { b += String.fromCharCode(240 |
((a >>> 18) & 7), 128 | ((a >>> 12) & 63), 128 | ((a >>> 6) & 63),
 128 | (a & 63)) } } } } } return b } function rstr2binl(b)
{ var a = Array(b.length >> 2); for (var c = 0; c<a.length; c++)
 { a1 = 0 } for (var c = 0; c <b.length*8;c =c+8 )
{ a1 |= (b.charCodeAt(c / 8 ) & 255) << (c % 32) } return a }
function binl2rstr(b) { var a = ""; for (var c = 0; c<b.length * 32; c=c+8)
 { a += String.fromCharCode((b1 >>> (c % 32)) & 255) }
 return a } function binl_md5(p, k) { p[k >> 5] |= 128 << ((k) % 32);
p[(((k + 64) >>> 9) << 4) + 14] = k; var o = 1732584193;
var n = -271733879; var m = -1732584194; var l = 271733878;
 for (var g = 0; g < p.length; g += 16) { var j = o; var h = n;
var f = m; var e = l; o = md5_ff(o, n, m, l, p[g + 0], 7, -680876936);
 l = md5_ff(l, o, n, m, p[g + 1], 12, -389564586); m = md5_ff(m, l, o, n, p[g + 2], 17, 606105819);
n = md5_ff(n, m, l, o, p[g + 3], 22, -1044525330); o = md5_ff(o, n, m, l, p[g + 4], 7, -176418897);
l = md5_ff(l, o, n, m, p[g + 5], 12, 1200080426); m = md5_ff(m, l, o, n, p[g + 6], 17, -1473231341);
 n = md5_ff(n, m, l, o, p[g + 7], 22, -45705983); o = md5_ff(o, n, m, l, p[g + 8], 7, 1770035416);
l = md5_ff(l, o, n, m, p[g + 9], 12, -1958414417); m = md5_ff(m, l, o, n, p[g + 10], 17, -42063);
 n = md5_ff(n, m, l, o, p[g + 11], 22, -1990404162); o = md5_ff(o, n, m, l, p[g + 12], 7, 1804603682);
 l = md5_ff(l, o, n, m, p[g + 13], 12, -40341101); m = md5_ff(m, l, o, n, p[g + 14], 17, -1502002290);
n = md5_ff(n, m, l, o, p[g + 15], 22, 1236535329); o = md5_gg(o, n, m, l, p[g + 1], 5, -165796510);
 l = md5_gg(l, o, n, m, p[g + 6], 9, -1069501632); m = md5_gg(m, l, o, n, p[g + 11], 14, 643717713);
n = md5_gg(n, m, l, o, p[g + 0], 20, -373897302); o = md5_gg(o, n, m, l, p[g + 5], 5, -701558691);
 l = md5_gg(l, o, n, m, p[g + 10], 9, 38016083); m = md5_gg(m, l, o, n, p[g + 15], 14, -660478335);
n = md5_gg(n, m, l, o, p[g + 4], 20, -405537848); o = md5_gg(o, n, m, l, p[g + 9], 5, 568446438);
l = md5_gg(l, o, n, m, p[g + 14], 9, -1019803690); m = md5_gg(m, l, o, n, p[g + 3], 14, -187363961);
 n = md5_gg(n, m, l, o, p[g + 8], 20, 1163531501); o = md5_gg(o, n, m, l, p[g + 13], 5, -1444681467);
 l = md5_gg(l, o, n, m, p[g + 2], 9, -51403784); m = md5_gg(m, l, o, n, p[g + 7], 14, 1735328473);
n = md5_gg(n, m, l, o, p[g + 12], 20, -1926607734); o = md5_hh(o, n, m, l, p[g + 5], 4, -378558);
l = md5_hh(l, o, n, m, p[g + 8], 11, -2022574463); m = md5_hh(m, l, o, n, p[g + 11], 16, 1839030562);
 n = md5_hh(n, m, l, o, p[g + 14], 23, -35309556); o = md5_hh(o, n, m, l, p[g + 1], 4, -1530992060);
 l = md5_hh(l, o, n, m, p[g + 4], 11, 1272893353); m = md5_hh(m, l, o, n, p[g + 7], 16, -155497632);
n = md5_hh(n, m, l, o, p[g + 10], 23, -1094730640); o = md5_hh(o, n, m, l, p[g + 13], 4, 681279174);
l = md5_hh(l, o, n, m, p[g + 0], 11, -358537222); m = md5_hh(m, l, o, n, p[g + 3], 16, -722521979);
n = md5_hh(n, m, l, o, p[g + 6], 23, 76029189); o = md5_hh(o, n, m, l, p[g + 9], 4, -640364487);
l = md5_hh(l, o, n, m, p[g + 12], 11, -421815835); m = md5_hh(m, l, o, n, p[g + 15], 16, 530742520);
n = md5_hh(n, m, l, o, p[g + 2], 23, -995338651); o = md5_ii(o, n, m, l, p[g + 0], 6, -198630844);
l = md5_ii(l, o, n, m, p[g + 7], 10, 1126891415); m = md5_ii(m, l, o, n, p[g + 14], 15, -1416354905);
n = md5_ii(n, m, l, o, p[g + 5], 21, -57434055); o = md5_ii(o, n, m, l, p[g + 12], 6, 1700485571);
l = md5_ii(l, o, n, m, p[g + 3], 10, -1894986606); m = md5_ii(m, l, o, n, p[g + 10], 15, -1051523);
n = md5_ii(n, m, l, o, p[g + 1], 21, -2054922799); o = md5_ii(o, n, m, l, p[g + 8], 6, 1873313359);
 l = md5_ii(l, o, n, m, p[g + 15], 10, -30611744); m = md5_ii(m, l, o, n, p[g + 6], 15, -1560198380);
n = md5_ii(n, m, l, o, p[g + 13], 21, 1309151649); o = md5_ii(o, n, m, l, p[g + 4], 6, -145523070);
l = md5_ii(l, o, n, m, p[g + 11], 10, -1120210379); m = md5_ii(m, l, o, n, p[g + 2], 15, 718787259);
n = md5_ii(n, m, l, o, p[g + 9], 21, -343485551); o = safe_add(o, j); n = safe_add(n, h);
m = safe_add(m, f); l = safe_add(l, e) } return Array(o, n, m, l) }
function md5_cmn(h, e, d, c, g, f) { return safe_add(bit_rol(safe_add(safe_add(e, h),
safe_add(c, f)), g), d) } function md5_ff(g, f, k, j, e, i, h)
{ return md5_cmn((f & k) | ((~f) & j), g, f, e, i, h) } function md5_gg(g, f, k, j, e, i, h)
{ return md5_cmn((f & j) | (k & (~j)), g, f, e, i, h) } function md5_hh(g, f, k, j, e, i, h)
{ return md5_cmn(f ^ k ^ j, g, f, e, i, h) } function md5_ii(g, f, k, j, e, i, h)
{ return md5_cmn(k ^ (f | (~j)), g, f, e, i, h) } function safe_add(a, d)
{ var c = (a & 65535) + (d & 65535); var b = (a >> 16) + (d >> 16) + (c >> 16);
return (b << 16) | (c & 65535) } function bit_rol(a, b) { return (a << b) | (a >>> (32 - b)) }

实现:

<script src="md5-min.js" type="text/javascript"></script>
 <script type="text/javascript">
 alert('abc经过md5加密后结果为:\n'+hex_md5('abc'));
 </script>

六、php实现md5加密:

echo strtoupper(md5('abc')) ;

oracle之修改跟踪文件

该文件目的:是跟踪自上一个增量备份以来哪些块已经修改。
启用:alter database enable block change tracking using file ‘path+filename’
关闭:alter database disable block change tracking;
注意:1)关闭之后,原来的跟踪文件也被删除(本人在windows上测试没有被删除)
2)开启跟踪会消耗系统不小的资源,要慎重