{"id":46,"date":"2010-06-09T18:27:03","date_gmt":"2010-06-09T10:27:03","guid":{"rendered":"http:\/\/zduo.me\/blog\/?p=46"},"modified":"2010-06-09T18:28:10","modified_gmt":"2010-06-09T10:28:10","slug":"mysql-%e4%b8%ad-%e6%97%b6%e9%97%b4%e5%92%8c%e6%97%a5%e6%9c%9f%e5%87%bd%e6%95%b0","status":"publish","type":"post","link":"http:\/\/zduo.me\/blog\/?p=46","title":{"rendered":"mysql \u4e2d \u65f6\u95f4\u548c\u65e5\u671f\u51fd\u6570"},"content":{"rendered":"

\u5f15\u7528\u5730\u5740\uff1ahttp:\/\/www.cnblogs.com\/redfox241\/archive\/2009\/07\/23\/1529092.html<\/a><\/p>\n

\u4e00\u3001MySQL\u00a0\u83b7\u5f97\u5f53\u524d\u65e5\u671f\u65f6\u95f4\u00a0\u51fd\u6570<\/p>\n

1.1\u00a0\u83b7\u5f97\u5f53\u524d\u65e5\u671f+\u65f6\u95f4\uff08date\u00a0+\u00a0time\uff09\u51fd\u6570\uff1anow()<\/p>\n

mysql>\u00a0select\u00a0now();<\/p>\n

+———————+
\n|\u00a0now()\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0|
\n+———————+
\n|\u00a02008-08-08\u00a022:20:46\u00a0|
\n+———————+<\/p>\n

\u9664\u4e86\u00a0now()\u00a0\u51fd\u6570\u80fd\u83b7\u5f97\u5f53\u524d\u7684\u65e5\u671f\u65f6\u95f4\u5916\uff0cMySQL\u00a0\u4e2d\u8fd8\u6709\u4e0b\u9762\u7684\u51fd\u6570\uff1a<\/p>\n

\u00a0current_timestamp()
\n,current_timestamp
\n,localtime()
\n,localtime
\n,localtimestamp\u00a0\u00a0\u00a0\u00a0—\u00a0(v4.0.6)
\n,localtimestamp()\u00a0\u00a0—\u00a0(v4.0.6)<\/p>\n

\u8fd9\u4e9b\u65e5\u671f\u65f6\u95f4\u51fd\u6570\uff0c\u90fd\u7b49\u540c\u4e8e\u00a0now()\u3002\u9274\u4e8e\u00a0now()\u00a0\u51fd\u6570\u7b80\u77ed\u6613\u8bb0\uff0c\u5efa\u8bae\u603b\u662f\u4f7f\u7528\u00a0now()\u00a0\u6765\u66ff\u4ee3\u4e0a\u9762\u5217\u51fa\u7684\u51fd\u6570\u3002<\/p>\n

1.2\u00a0\u83b7\u5f97\u5f53\u524d\u65e5\u671f+\u65f6\u95f4\uff08date\u00a0+\u00a0time\uff09\u51fd\u6570\uff1asysdate()<\/p>\n

sysdate()\u00a0\u65e5\u671f\u65f6\u95f4\u51fd\u6570\u8ddf\u00a0now()\u00a0\u7c7b\u4f3c\uff0c\u4e0d\u540c\u4e4b\u5904\u5728\u4e8e\uff1anow()\u00a0\u5728\u6267\u884c\u5f00\u59cb\u65f6\u503c\u5c31\u5f97\u5230\u4e86\uff0c\u00a0sysdate()\u00a0\u5728\u51fd\u6570\u6267\u884c\u65f6\u52a8\u6001\u5f97\u5230\u503c\u3002\u770b\u4e0b\u9762\u7684\u4f8b\u5b50\u5c31\u660e\u767d\u4e86\uff1a<\/p>\n

mysql>\u00a0select\u00a0now(),\u00a0sleep(3),\u00a0now();<\/p>\n

+———————+———-+———————+
\n|\u00a0now()\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0|\u00a0sleep(3)\u00a0|\u00a0now()\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0|
\n+———————+———-+———————+
\n|\u00a02008-08-08\u00a022:28:21\u00a0|\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a00\u00a0|\u00a02008-08-08\u00a022:28:21\u00a0|
\n+———————+———-+———————+<\/p>\n

mysql>\u00a0select\u00a0sysdate(),\u00a0sleep(3),\u00a0sysdate();<\/p>\n

+———————+———-+———————+
\n|\u00a0sysdate()\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0|\u00a0sleep(3)\u00a0|\u00a0sysdate()\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0|
\n+———————+———-+———————+
\n|\u00a02008-08-08\u00a022:28:41\u00a0|\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a00\u00a0|\u00a02008-08-08\u00a022:28:44\u00a0|
\n+———————+———-+———————+<\/p>\n

\u53ef\u4ee5\u770b\u5230\uff0c\u867d\u7136\u4e2d\u9014\u00a0sleep\u00a03\u00a0\u79d2\uff0c\u4f46\u00a0now()\u00a0\u51fd\u6570\u4e24\u6b21\u7684\u65f6\u95f4\u503c\u662f\u76f8\u540c\u7684\uff1b\u00a0sysdate()\u00a0\u51fd\u6570\u4e24\u6b21\u5f97\u5230\u7684\u65f6\u95f4\u503c\u76f8\u5dee\u00a03\u00a0\u79d2\u3002MySQL\u00a0Manual\u00a0\u4e2d\u662f\u8fd9\u6837\u63cf\u8ff0\u00a0sysdate()\u00a0\u7684\uff1aReturn\u00a0the\u00a0time\u00a0at\u00a0which\u00a0the\u00a0function\u00a0executes\u3002<\/p>\n

sysdate()\u00a0\u65e5\u671f\u65f6\u95f4\u51fd\u6570\uff0c\u4e00\u822c\u60c5\u51b5\u4e0b\u5f88\u5c11\u7528\u5230\u3002<\/p>\n

2.\u00a0\u83b7\u5f97\u5f53\u524d\u65e5\u671f\uff08date\uff09\u51fd\u6570\uff1acurdate()<\/p>\n

mysql>\u00a0select\u00a0curdate();<\/p>\n

+————+
\n|\u00a0curdate()\u00a0\u00a0|
\n+————+
\n|\u00a02008-08-08\u00a0|
\n+————+<\/p>\n

\u5176\u4e2d\uff0c\u4e0b\u9762\u7684\u4e24\u4e2a\u65e5\u671f\u51fd\u6570\u7b49\u540c\u4e8e\u00a0curdate()\uff1a<\/p>\n

\u00a0current_date()
\n,current_date<\/p>\n

3.\u00a0\u83b7\u5f97\u5f53\u524d\u65f6\u95f4\uff08time\uff09\u51fd\u6570\uff1acurtime()<\/p>\n

mysql>\u00a0select\u00a0curtime();<\/p>\n

+———–+
\n|\u00a0curtime()\u00a0|
\n+———–+
\n|\u00a022:41:30\u00a0\u00a0|
\n+———–+<\/p>\n

\u5176\u4e2d\uff0c\u4e0b\u9762\u7684\u4e24\u4e2a\u65f6\u95f4\u51fd\u6570\u7b49\u540c\u4e8e\u00a0curtime()\uff1a<\/p>\n

\u00a0current_time()
\n,current_time<\/p>\n

4.\u00a0\u83b7\u5f97\u5f53\u524d\u00a0UTC\u00a0\u65e5\u671f\u65f6\u95f4\u51fd\u6570\uff1autc_date(),\u00a0utc_time(),\u00a0utc_timestamp()<\/p>\n

mysql>\u00a0select\u00a0utc_timestamp(),\u00a0utc_date(),\u00a0utc_time(),\u00a0now()<\/p>\n

+———————+————+————+———————+
\n|\u00a0utc_timestamp()\u00a0\u00a0\u00a0\u00a0\u00a0|\u00a0utc_date()\u00a0|\u00a0utc_time()\u00a0|\u00a0now()\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0|
\n+———————+————+————+———————+
\n|\u00a02008-08-08\u00a014:47:11\u00a0|\u00a02008-08-08\u00a0|\u00a014:47:11\u00a0\u00a0\u00a0|\u00a02008-08-08\u00a022:47:11\u00a0|
\n+———————+————+————+———————+<\/p>\n

\u56e0\u4e3a\u6211\u56fd\u4f4d\u4e8e\u4e1c\u516b\u65f6\u533a\uff0c\u6240\u4ee5\u672c\u5730\u65f6\u95f4\u00a0=\u00a0UTC\u00a0\u65f6\u95f4\u00a0+\u00a08\u00a0\u5c0f\u65f6\u3002UTC\u00a0\u65f6\u95f4\u5728\u4e1a\u52a1\u6d89\u53ca\u591a\u4e2a\u56fd\u5bb6\u548c\u5730\u533a\u7684\u65f6\u5019\uff0c\u975e\u5e38\u6709\u7528\u3002
\n\u4e8c\u3001MySQL\u00a0\u65e5\u671f\u65f6\u95f4\u00a0Extract\uff08\u9009\u53d6\uff09\u00a0\u51fd\u6570\u3002<\/p>\n

1.\u00a0\u9009\u53d6\u65e5\u671f\u65f6\u95f4\u7684\u5404\u4e2a\u90e8\u5206\uff1a\u65e5\u671f\u3001\u65f6\u95f4\u3001\u5e74\u3001\u5b63\u5ea6\u3001\u6708\u3001\u65e5\u3001\u5c0f\u65f6\u3001\u5206\u949f\u3001\u79d2\u3001\u5fae\u79d2<\/p>\n

set\u00a0@dt\u00a0=\u00a0‘2008-09-10\u00a007:15:30.123456’;<\/p>\n

select\u00a0date(@dt);\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0—\u00a02008-09-10
\nselect\u00a0time(@dt);\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0—\u00a007:15:30.123456
\nselect\u00a0year(@dt);\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0—\u00a02008
\nselect\u00a0quarter(@dt);\u00a0\u00a0\u00a0\u00a0\u00a0—\u00a03
\nselect\u00a0month(@dt);\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0—\u00a09
\nselect\u00a0week(@dt);\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0—\u00a036
\nselect\u00a0day(@dt);\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0—\u00a010
\nselect\u00a0hour(@dt);\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0—\u00a07
\nselect\u00a0minute(@dt);\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0—\u00a015
\nselect\u00a0second(@dt);\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0—\u00a030
\nselect\u00a0microsecond(@dt);\u00a0—\u00a0123456<\/p>\n

2.\u00a0MySQL\u00a0Extract()\u00a0\u51fd\u6570\uff0c\u53ef\u4ee5\u4e0a\u9762\u5b9e\u73b0\u7c7b\u4f3c\u7684\u529f\u80fd\uff1a<\/p>\n

set\u00a0@dt\u00a0=\u00a0‘2008-09-10\u00a007:15:30.123456’;<\/p>\n

select\u00a0extract(year\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0from\u00a0@dt);\u00a0—\u00a02008
\nselect\u00a0extract(quarter\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0from\u00a0@dt);\u00a0—\u00a03
\nselect\u00a0extract(month\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0from\u00a0@dt);\u00a0—\u00a09
\nselect\u00a0extract(week\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0from\u00a0@dt);\u00a0—\u00a036
\nselect\u00a0extract(day\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0from\u00a0@dt);\u00a0—\u00a010
\nselect\u00a0extract(hour\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0from\u00a0@dt);\u00a0—\u00a07
\nselect\u00a0extract(minute\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0from\u00a0@dt);\u00a0—\u00a015
\nselect\u00a0extract(second\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0from\u00a0@dt);\u00a0—\u00a030
\nselect\u00a0extract(microsecond\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0from\u00a0@dt);\u00a0—\u00a0123456<\/p>\n

select\u00a0extract(year_month\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0from\u00a0@dt);\u00a0—\u00a0200809
\nselect\u00a0extract(day_hour\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0from\u00a0@dt);\u00a0—\u00a01007
\nselect\u00a0extract(day_minute\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0from\u00a0@dt);\u00a0—\u00a0100715
\nselect\u00a0extract(day_second\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0from\u00a0@dt);\u00a0—\u00a010071530
\nselect\u00a0extract(day_microsecond\u00a0\u00a0\u00a0\u00a0\u00a0from\u00a0@dt);\u00a0—\u00a010071530123456
\nselect\u00a0extract(hour_minute\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0from\u00a0@dt);\u00a0—\u00a0\u00a0\u00a0\u00a0715
\nselect\u00a0extract(hour_second\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0from\u00a0@dt);\u00a0—\u00a0\u00a0\u00a0\u00a071530
\nselect\u00a0extract(hour_microsecond\u00a0\u00a0\u00a0\u00a0from\u00a0@dt);\u00a0—\u00a0\u00a0\u00a0\u00a071530123456
\nselect\u00a0extract(minute_second\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0from\u00a0@dt);\u00a0—\u00a0\u00a0\u00a0\u00a0\u00a0\u00a01530
\nselect\u00a0extract(minute_microsecond\u00a0\u00a0from\u00a0@dt);\u00a0—\u00a0\u00a0\u00a0\u00a0\u00a0\u00a01530123456
\nselect\u00a0extract(second_microsecond\u00a0\u00a0from\u00a0@dt);\u00a0—\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a030123456<\/p>\n

MySQL\u00a0Extract()\u00a0\u51fd\u6570\u9664\u4e86\u6ca1\u6709date(),time()\u00a0\u7684\u529f\u80fd\u5916\uff0c\u5176\u4ed6\u529f\u80fd\u4e00\u5e94\u5177\u5168\u3002\u5e76\u4e14\u8fd8\u5177\u6709\u9009\u53d6\u2018day_microsecond\u2019\u00a0\u7b49\u529f\u80fd\u3002\u6ce8\u610f\u8fd9\u91cc\u4e0d\u662f\u53ea\u9009\u53d6\u00a0day\u00a0\u548c\u00a0microsecond\uff0c\u800c\u662f\u4ece\u65e5\u671f\u7684\u00a0day\u00a0\u90e8\u5206\u4e00\u76f4\u9009\u53d6\u5230\u00a0microsecond\u00a0\u90e8\u5206\u3002\u591f\u5f3a\u608d\u7684\u5427\uff01<\/p>\n

MySQL\u00a0Extract()\u00a0\u51fd\u6570\u552f\u4e00\u4e0d\u597d\u7684\u5730\u65b9\u5728\u4e8e\uff1a\u4f60\u9700\u8981\u591a\u6572\u51e0\u6b21\u952e\u76d8\u3002<\/p>\n

3.\u00a0MySQL\u00a0dayof\u2026\u00a0\u51fd\u6570\uff1adayofweek(),\u00a0dayofmonth(),\u00a0dayofyear()<\/p>\n

\u5206\u522b\u8fd4\u56de\u65e5\u671f\u53c2\u6570\uff0c\u5728\u4e00\u5468\u3001\u4e00\u6708\u3001\u4e00\u5e74\u4e2d\u7684\u4f4d\u7f6e\u3002<\/p>\n

set\u00a0@dt\u00a0=\u00a0‘2008-08-08’;<\/p>\n

select\u00a0dayofweek(@dt);\u00a0\u00a0\u00a0—\u00a06
\nselect\u00a0dayofmonth(@dt);\u00a0\u00a0—\u00a08
\nselect\u00a0dayofyear(@dt);\u00a0\u00a0\u00a0—\u00a0221<\/p>\n

\u65e5\u671f\u00a0\u20182008-08-08\u2032\u00a0\u662f\u4e00\u5468\u4e2d\u7684\u7b2c\u00a06\u00a0\u5929\uff081\u00a0=\u00a0Sunday,\u00a02\u00a0=\u00a0Monday,\u00a0\u2026,\u00a07\u00a0=\u00a0Saturday\uff09\uff1b\u4e00\u6708\u4e2d\u7684\u7b2c\u00a08\u00a0\u5929\uff1b\u4e00\u5e74\u4e2d\u7684\u7b2c\u00a0221\u00a0\u5929\u3002<\/p>\n

4.\u00a0MySQL\u00a0week\u2026\u00a0\u51fd\u6570\uff1aweek(),\u00a0weekofyear(),\u00a0dayofweek(),\u00a0weekday(),\u00a0yearweek()<\/p>\n

set\u00a0@dt\u00a0=\u00a0‘2008-08-08’;<\/p>\n

select\u00a0week(@dt);\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0—\u00a031
\nselect\u00a0week(@dt,3);\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0—\u00a032
\nselect\u00a0weekofyear(@dt);\u00a0\u00a0—\u00a032<\/p>\n

select\u00a0dayofweek(@dt);\u00a0\u00a0\u00a0—\u00a06
\nselect\u00a0weekday(@dt);\u00a0\u00a0\u00a0\u00a0\u00a0—\u00a04<\/p>\n

select\u00a0yearweek(@dt);\u00a0\u00a0\u00a0\u00a0—\u00a0200831<\/p>\n

MySQL\u00a0week()\u00a0\u51fd\u6570\uff0c\u53ef\u4ee5\u6709\u4e24\u4e2a\u53c2\u6570\uff0c\u5177\u4f53\u53ef\u770b\u624b\u518c\u3002\u00a0weekofyear()\u00a0\u548c\u00a0week()\u00a0\u4e00\u6837\uff0c\u90fd\u662f\u8ba1\u7b97\u201c\u67d0\u5929\u201d\u662f\u4f4d\u4e8e\u4e00\u5e74\u4e2d\u7684\u7b2c\u51e0\u5468\u3002\u00a0weekofyear(@dt)\u00a0\u7b49\u4ef7\u4e8e\u00a0week(@dt,3)\u3002<\/p>\n

MySQL\u00a0weekday()\u00a0\u51fd\u6570\u548c\u00a0dayofweek()\u00a0\u7c7b\u4f3c\uff0c\u90fd\u662f\u8fd4\u56de\u201c\u67d0\u5929\u201d\u5728\u4e00\u5468\u4e2d\u7684\u4f4d\u7f6e\u3002\u4e0d\u540c\u70b9\u5728\u4e8e\u53c2\u8003\u7684\u6807\u51c6\uff0c\u00a0weekday\uff1a(0\u00a0=\u00a0Monday,\u00a01\u00a0=\u00a0Tuesday,\u00a0\u2026,\u00a06\u00a0=\u00a0Sunday)\uff1b\u00a0dayofweek\uff1a\uff081\u00a0=\u00a0Sunday,\u00a02\u00a0=\u00a0Monday,\u00a0\u2026,\u00a07\u00a0=\u00a0Saturday\uff09<\/p>\n

MySQL\u00a0yearweek()\u00a0\u51fd\u6570\uff0c\u8fd4\u56de\u00a0year(2008)\u00a0+\u00a0week\u00a0\u4f4d\u7f6e(31)\u3002<\/p>\n

5.\u00a0MySQL\u00a0\u8fd4\u56de\u661f\u671f\u548c\u6708\u4efd\u540d\u79f0\u51fd\u6570\uff1adayname(),\u00a0monthname()<\/p>\n

set\u00a0@dt\u00a0=\u00a0‘2008-08-08’;<\/p>\n

select\u00a0dayname(@dt);\u00a0\u00a0\u00a0\u00a0\u00a0—\u00a0Friday
\nselect\u00a0monthname(@dt);\u00a0\u00a0\u00a0—\u00a0August<\/p>\n

\u601d\u8003\uff0c\u5982\u4f55\u8fd4\u56de\u4e2d\u6587\u7684\u540d\u79f0\u5462\uff1f<\/p>\n

6.\u00a0MySQL\u00a0last_day()\u00a0\u51fd\u6570\uff1a\u8fd4\u56de\u6708\u4efd\u4e2d\u7684\u6700\u540e\u4e00\u5929\u3002<\/p>\n

select\u00a0last_day(‘2008-02-01’);\u00a0\u00a0—\u00a02008-02-29
\nselect\u00a0last_day(‘2008-08-08’);\u00a0\u00a0—\u00a02008-08-31<\/p>\n

MySQL\u00a0last_day()\u00a0\u51fd\u6570\u975e\u5e38\u6709\u7528\uff0c\u6bd4\u5982\u6211\u60f3\u5f97\u5230\u5f53\u524d\u6708\u4efd\u4e2d\u6709\u591a\u5c11\u5929\uff0c\u53ef\u4ee5\u8fd9\u6837\u6765\u8ba1\u7b97\uff1a<\/p>\n

mysql>\u00a0select\u00a0now(),\u00a0day(last_day(now()))\u00a0as\u00a0days;<\/p>\n

+———————+——+
\n|\u00a0now()\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0|\u00a0days\u00a0|
\n+———————+——+
\n|\u00a02008-08-09\u00a011:45:45\u00a0|\u00a0\u00a0\u00a031\u00a0|
\n+———————+——+<\/p>\n

\u4e09\u3001MySQL\u00a0\u65e5\u671f\u65f6\u95f4\u8ba1\u7b97\u51fd\u6570<\/p>\n

1.\u00a0MySQL\u00a0\u4e3a\u65e5\u671f\u589e\u52a0\u4e00\u4e2a\u65f6\u95f4\u95f4\u9694\uff1adate_add()<\/p>\n

set\u00a0@dt\u00a0=\u00a0now();<\/p>\n

select\u00a0date_add(@dt,\u00a0interval\u00a01\u00a0day);\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0—\u00a0add\u00a01\u00a0day
\nselect\u00a0date_add(@dt,\u00a0interval\u00a01\u00a0hour);\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0—\u00a0add\u00a01\u00a0hour
\nselect\u00a0date_add(@dt,\u00a0interval\u00a01\u00a0minute);\u00a0\u00a0\u00a0\u00a0\u00a0—\u00a0\"\"
\nselect\u00a0date_add(@dt,\u00a0interval\u00a01\u00a0second);
\nselect\u00a0date_add(@dt,\u00a0interval\u00a01\u00a0microsecond);
\nselect\u00a0date_add(@dt,\u00a0interval\u00a01\u00a0week);
\nselect\u00a0date_add(@dt,\u00a0interval\u00a01\u00a0month);
\nselect\u00a0date_add(@dt,\u00a0interval\u00a01\u00a0quarter);
\nselect\u00a0date_add(@dt,\u00a0interval\u00a01\u00a0year);<\/p>\n

select\u00a0date_add(@dt,\u00a0interval\u00a0-1\u00a0day);\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0—\u00a0sub\u00a01\u00a0day<\/p>\n

MySQL\u00a0adddate(),\u00a0addtime()\u51fd\u6570\uff0c\u53ef\u4ee5\u7528\u00a0date_add()\u00a0\u6765\u66ff\u4ee3\u3002\u4e0b\u9762\u662f\u00a0date_add()\u00a0\u5b9e\u73b0\u00a0addtime()\u00a0\u529f\u80fd\u793a\u4f8b\uff1a<\/p>\n

mysql>\u00a0set\u00a0@dt\u00a0=\u00a0‘2008-08-09\u00a012:12:33′;<\/p>\n

mysql>
\nmysql>\u00a0select\u00a0date_add(@dt,\u00a0interval\u00a0’01:15:30′\u00a0hour_second);<\/p>\n

+————————————————+
\n|\u00a0date_add(@dt,\u00a0interval\u00a0’01:15:30’\u00a0hour_second)\u00a0|
\n+————————————————+
\n|\u00a02008-08-09\u00a013:28:03\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0|
\n+————————————————+<\/p>\n

mysql>\u00a0select\u00a0date_add(@dt,\u00a0interval\u00a0‘1\u00a001:15:30’\u00a0day_second);<\/p>\n

+————————————————-+
\n|\u00a0date_add(@dt,\u00a0interval\u00a0‘1\u00a001:15:30’\u00a0day_second)\u00a0|
\n+————————————————-+
\n|\u00a02008-08-10\u00a013:28:03\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0|
\n+————————————————-+<\/p>\n

date_add()\u00a0\u51fd\u6570\uff0c\u5206\u522b\u4e3a\u00a0@dt\u00a0\u589e\u52a0\u4e86\u201c1\u5c0f\u65f6\u00a015\u5206\u00a030\u79d2\u201d\u00a0\u548c\u00a0\u201c1\u5929\u00a01\u5c0f\u65f6\u00a015\u5206\u00a030\u79d2\u201d\u3002\u5efa\u8bae\uff1a\u603b\u662f\u4f7f\u7528\u00a0date_add()\u00a0\u65e5\u671f\u65f6\u95f4\u51fd\u6570\u6765\u66ff\u4ee3\u00a0adddate(),\u00a0addtime()\u3002<\/p>\n

2.\u00a0MySQL\u00a0\u4e3a\u65e5\u671f\u51cf\u53bb\u4e00\u4e2a\u65f6\u95f4\u95f4\u9694\uff1adate_sub()<\/p>\n

mysql>\u00a0select\u00a0date_sub(‘1998-01-01\u00a000:00:00’,\u00a0interval\u00a0‘1\u00a01:1:1’\u00a0day_second);<\/p>\n

+—————————————————————-+
\n|\u00a0date_sub(‘1998-01-01\u00a000:00:00’,\u00a0interval\u00a0‘1\u00a01:1:1’\u00a0day_second)\u00a0|
\n+—————————————————————-+
\n|\u00a01997-12-30\u00a022:58:59\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0|
\n+—————————————————————-+<\/p>\n

MySQL\u00a0date_sub()\u00a0\u65e5\u671f\u65f6\u95f4\u51fd\u6570\u00a0\u548c\u00a0date_add()\u00a0\u7528\u6cd5\u4e00\u81f4\uff0c\u4e0d\u518d\u8d58\u8ff0\u3002\u53e6\u5916\uff0cMySQL\u00a0\u4e2d\u8fd8\u6709\u4e24\u4e2a\u51fd\u6570\u00a0subdate(),\u00a0subtime()\uff0c\u5efa\u8bae\uff0c\u7528\u00a0date_sub()\u00a0\u6765\u66ff\u4ee3\u3002<\/p>\n

3.\u00a0MySQL\u00a0\u53e6\u7c7b\u65e5\u671f\u51fd\u6570\uff1aperiod_add(P,N),\u00a0period_diff(P1,P2)<\/p>\n

\u51fd\u6570\u53c2\u6570\u201cP\u201d\u00a0\u7684\u683c\u5f0f\u4e3a\u201cYYYYMM\u201d\u00a0\u6216\u8005\u00a0\u201cYYMM\u201d\uff0c\u7b2c\u4e8c\u4e2a\u53c2\u6570\u201cN\u201d\u00a0\u8868\u793a\u589e\u52a0\u6216\u51cf\u53bb\u00a0N\u00a0month\uff08\u6708\uff09\u3002<\/p>\n

MySQL\u00a0period_add(P,N)\uff1a\u65e5\u671f\u52a0\/\u51cf\u53bbN\u6708\u3002<\/p>\n

mysql>\u00a0select\u00a0period_add(200808,2),\u00a0period_add(20080808,-2)<\/p>\n

+———————-+————————-+
\n|\u00a0period_add(200808,2)\u00a0|\u00a0period_add(20080808,-2)\u00a0|
\n+———————-+————————-+
\n|\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0200810\u00a0|\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a020080806\u00a0|
\n+———————-+————————-+<\/p>\n

MySQL\u00a0period_diff(P1,P2)\uff1a\u65e5\u671f\u00a0P1-P2\uff0c\u8fd4\u56de\u00a0N\u00a0\u4e2a\u6708\u3002<\/p>\n

mysql>\u00a0select\u00a0period_diff(200808,\u00a0200801);<\/p>\n

+—————————–+
\n|\u00a0period_diff(200808,\u00a0200801)\u00a0|
\n+—————————–+
\n|\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a07\u00a0|
\n+—————————–+<\/p>\n

\u5728\u00a0MySQL\u00a0\u4e2d\uff0c\u8fd9\u4e24\u4e2a\u65e5\u671f\u51fd\u6570\uff0c\u4e00\u822c\u60c5\u51b5\u4e0b\u5f88\u5c11\u7528\u5230\u3002<\/p>\n

4.\u00a0MySQL\u00a0\u65e5\u671f\u3001\u65f6\u95f4\u76f8\u51cf\u51fd\u6570\uff1adatediff(date1,date2),\u00a0timediff(time1,time2)<\/p>\n

MySQL\u00a0datediff(date1,date2)\uff1a\u4e24\u4e2a\u65e5\u671f\u76f8\u51cf\u00a0date1\u00a0–\u00a0date2\uff0c\u8fd4\u56de\u5929\u6570\u3002<\/p>\n

select\u00a0datediff(‘2008-08-08’,\u00a0‘2008-08-01’);\u00a0\u00a0—\u00a07
\nselect\u00a0datediff(‘2008-08-01’,\u00a0‘2008-08-08’);\u00a0\u00a0—\u00a0-7<\/p>\n

MySQL\u00a0timediff(time1,time2)\uff1a\u4e24\u4e2a\u65e5\u671f\u76f8\u51cf\u00a0time1\u00a0–\u00a0time2\uff0c\u8fd4\u56de\u00a0time\u00a0\u5dee\u503c\u3002<\/p>\n

select\u00a0timediff(‘2008-08-08\u00a008:08:08’,\u00a0‘2008-08-08\u00a000:00:00′);\u00a0—\u00a008:08:08
\nselect\u00a0timediff(’08:08:08′,\u00a0’00:00:00′);\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0—\u00a008:08:08<\/p>\n

\u6ce8\u610f\uff1atimediff(time1,time2)\u00a0\u51fd\u6570\u7684\u4e24\u4e2a\u53c2\u6570\u7c7b\u578b\u5fc5\u987b\u76f8\u540c\u3002
\n\u56db\u3001MySQL\u00a0\u65e5\u671f\u8f6c\u6362\u51fd\u6570\u3001\u65f6\u95f4\u8f6c\u6362\u51fd\u6570<\/p>\n

1.\u00a0MySQL\u00a0\uff08\u65f6\u95f4\u3001\u79d2\uff09\u8f6c\u6362\u51fd\u6570\uff1atime_to_sec(time),\u00a0sec_to_time(seconds)<\/p>\n

select\u00a0time_to_sec(’01:00:05′);\u00a0\u00a0—\u00a03605
\nselect\u00a0sec_to_time(3605);\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0—\u00a0’01:00:05’<\/p>\n

2.\u00a0MySQL\u00a0\uff08\u65e5\u671f\u3001\u5929\u6570\uff09\u8f6c\u6362\u51fd\u6570\uff1ato_days(date),\u00a0from_days(days)<\/p>\n

select\u00a0to_days(‘0000-00-00’);\u00a0\u00a0—\u00a00
\nselect\u00a0to_days(‘2008-08-08’);\u00a0\u00a0—\u00a0733627<\/p>\n

select\u00a0from_days(0);\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0—\u00a0‘0000-00-00’
\nselect\u00a0from_days(733627);\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0—\u00a0‘2008-08-08′<\/p>\n

3.\u00a0MySQL\u00a0Str\u00a0to\u00a0Date\u00a0\uff08\u5b57\u7b26\u4e32\u8f6c\u6362\u4e3a\u65e5\u671f\uff09\u51fd\u6570\uff1astr_to_date(str,\u00a0format)<\/p>\n

select\u00a0str_to_date(’08\/09\/2008’,\u00a0‘%m\/%d\/%Y’);\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0—\u00a02008-08-09
\nselect\u00a0str_to_date(’08\/09\/08′\u00a0\u00a0,\u00a0‘%m\/%d\/%y’);\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0—\u00a02008-08-09
\nselect\u00a0str_to_date(‘08.09.2008’,\u00a0‘%m.%d.%Y’);\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0—\u00a02008-08-09
\nselect\u00a0str_to_date(’08:09:30′,\u00a0‘%h:%i:%s’);\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0—\u00a008:09:30
\nselect\u00a0str_to_date(‘08.09.2008\u00a008:09:30’,\u00a0‘%m.%d.%Y\u00a0%h:%i:%s’);\u00a0—\u00a02008-08-09\u00a008:09:30<\/p>\n

\u53ef\u4ee5\u770b\u5230\uff0cstr_to_date(str,format)\u00a0\u8f6c\u6362\u51fd\u6570\uff0c\u53ef\u4ee5\u628a\u4e00\u4e9b\u6742\u4e71\u65e0\u7ae0\u7684\u5b57\u7b26\u4e32\u8f6c\u6362\u4e3a\u65e5\u671f\u683c\u5f0f\u3002\u53e6\u5916\uff0c\u5b83\u4e5f\u53ef\u4ee5\u8f6c\u6362\u4e3a\u65f6\u95f4\u3002\u201cformat\u201d\u00a0\u53ef\u4ee5\u53c2\u770b\u00a0MySQL\u00a0\u624b\u518c\u3002<\/p>\n

4.\u00a0MySQL\u00a0Date\/Time\u00a0to\u00a0Str\uff08\u65e5\u671f\/\u65f6\u95f4\u8f6c\u6362\u4e3a\u5b57\u7b26\u4e32\uff09\u51fd\u6570\uff1adate_format(date,format),\u00a0time_format(time,format)<\/p>\n

mysql>\u00a0select\u00a0date_format(‘2008-08-08\u00a022:23:00’,\u00a0‘%W\u00a0%M\u00a0%Y’);<\/p>\n

+————————————————+
\n|\u00a0date_format(‘2008-08-08\u00a022:23:00’,\u00a0‘%W\u00a0%M\u00a0%Y’)\u00a0|
\n+————————————————+
\n|\u00a0Friday\u00a0August\u00a02008\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0|
\n+————————————————+<\/p>\n

mysql>\u00a0select\u00a0date_format(‘2008-08-08\u00a022:23:01’,\u00a0‘%Y%m%d%H%i%s’);<\/p>\n

+—————————————————-+
\n|\u00a0date_format(‘2008-08-08\u00a022:23:01’,\u00a0‘%Y%m%d%H%i%s’)\u00a0|
\n+—————————————————-+
\n|\u00a020080808222301\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0|
\n+—————————————————-+<\/p>\n

mysql>\u00a0select\u00a0time_format(’22:23:01′,\u00a0‘%H.%i.%s’);<\/p>\n

+————————————-+
\n|\u00a0time_format(’22:23:01′,\u00a0‘%H.%i.%s’)\u00a0|
\n+————————————-+
\n|\u00a022.23.01\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0|
\n+————————————-+<\/p>\n

MySQL\u00a0\u65e5\u671f\u3001\u65f6\u95f4\u8f6c\u6362\u51fd\u6570\uff1adate_format(date,format),\u00a0time_format(time,format)\u00a0\u80fd\u591f\u628a\u4e00\u4e2a\u65e5\u671f\/\u65f6\u95f4\u8f6c\u6362\u6210\u5404\u79cd\u5404\u6837\u7684\u5b57\u7b26\u4e32\u683c\u5f0f\u3002\u5b83\u662f\u00a0str_to_date(str,format)\u00a0\u51fd\u6570\u7684\u00a0\u4e00\u4e2a\u9006\u8f6c\u6362\u3002<\/p>\n

5.\u00a0MySQL\u00a0\u83b7\u5f97\u56fd\u5bb6\u5730\u533a\u65f6\u95f4\u683c\u5f0f\u51fd\u6570\uff1aget_format()<\/p>\n

MySQL\u00a0get_format()\u00a0\u8bed\u6cd5\uff1a<\/p>\n

get_format(date|time|datetime,\u00a0‘eur’|’usa’|’jis’|’iso’|’internal’<\/p>\n

MySQL\u00a0get_format()\u00a0\u7528\u6cd5\u7684\u5168\u90e8\u793a\u4f8b\uff1a<\/p>\n

select\u00a0get_format(date,’usa’)\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0;\u00a0\u00a0\u00a0—\u00a0‘%m.%d.%Y’
\nselect\u00a0get_format(date,’jis’)\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0;\u00a0\u00a0\u00a0—\u00a0‘%Y-%m-%d’
\nselect\u00a0get_format(date,’iso’)\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0;\u00a0\u00a0\u00a0—\u00a0‘%Y-%m-%d’
\nselect\u00a0get_format(date,’eur’)\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0;\u00a0\u00a0\u00a0—\u00a0‘%d.%m.%Y’
\nselect\u00a0get_format(date,’internal’)\u00a0\u00a0\u00a0\u00a0\u00a0;\u00a0\u00a0\u00a0—\u00a0‘%Y%m%d’
\nselect\u00a0get_format(datetime,’usa’)\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0;\u00a0\u00a0\u00a0—\u00a0‘%Y-%m-%d\u00a0%H.%i.%s’
\nselect\u00a0get_format(datetime,’jis’)\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0;\u00a0\u00a0\u00a0—\u00a0‘%Y-%m-%d\u00a0%H:%i:%s’
\nselect\u00a0get_format(datetime,’iso’)\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0;\u00a0\u00a0\u00a0—\u00a0‘%Y-%m-%d\u00a0%H:%i:%s’
\nselect\u00a0get_format(datetime,’eur’)\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0;\u00a0\u00a0\u00a0—\u00a0‘%Y-%m-%d\u00a0%H.%i.%s’
\nselect\u00a0get_format(datetime,’internal’)\u00a0;\u00a0\u00a0\u00a0—\u00a0‘%Y%m%d%H%i%s’
\nselect\u00a0get_format(time,’usa’)\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0;\u00a0\u00a0\u00a0—\u00a0‘%h:%i:%s\u00a0%p’
\nselect\u00a0get_format(time,’jis’)\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0;\u00a0\u00a0\u00a0—\u00a0‘%H:%i:%s’
\nselect\u00a0get_format(time,’iso’)\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0;\u00a0\u00a0\u00a0—\u00a0‘%H:%i:%s’
\nselect\u00a0get_format(time,’eur’)\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0;\u00a0\u00a0\u00a0—\u00a0‘%H.%i.%s’
\nselect\u00a0get_format(time,’internal’)\u00a0\u00a0\u00a0\u00a0\u00a0;\u00a0\u00a0\u00a0—\u00a0‘%H%i%s’<\/p>\n

MySQL\u00a0get_format()\u00a0\u51fd\u6570\u5728\u5b9e\u9645\u4e2d\u7528\u5230\u673a\u4f1a\u7684\u6bd4\u8f83\u5c11\u3002<\/p>\n

6.\u00a0MySQL\u00a0\u62fc\u51d1\u65e5\u671f\u3001\u65f6\u95f4\u51fd\u6570\uff1amakdedate(year,dayofyear),\u00a0maketime(hour,minute,second)<\/p>\n

select\u00a0makedate(2001,31);\u00a0\u00a0\u00a0—\u00a0‘2001-01-31’
\nselect\u00a0makedate(2001,32);\u00a0\u00a0\u00a0—\u00a0‘2001-02-01′<\/p>\n

select\u00a0maketime(12,15,30);\u00a0\u00a0—\u00a0’12:15:30’<\/p>\n

\u4e94\u3001MySQL\u00a0\u65f6\u95f4\u6233\uff08Timestamp\uff09\u51fd\u6570<\/p>\n

1.\u00a0MySQL\u00a0\u83b7\u5f97\u5f53\u524d\u65f6\u95f4\u6233\u51fd\u6570\uff1acurrent_timestamp,\u00a0current_timestamp()<\/p>\n

mysql>\u00a0select\u00a0current_timestamp,\u00a0current_timestamp();<\/p>\n

+———————+———————+
\n|\u00a0current_timestamp\u00a0\u00a0\u00a0|\u00a0current_timestamp()\u00a0|
\n+———————+———————+
\n|\u00a02008-08-09\u00a023:22:24\u00a0|\u00a02008-08-09\u00a023:22:24\u00a0|
\n+———————+———————+<\/p>\n

2.\u00a0MySQL\u00a0\uff08Unix\u00a0\u65f6\u95f4\u6233\u3001\u65e5\u671f\uff09\u8f6c\u6362\u51fd\u6570\uff1a<\/p>\n

unix_timestamp(),
\nunix_timestamp(date),
\nfrom_unixtime(unix_timestamp),
\nfrom_unixtime(unix_timestamp,format)<\/p>\n

\u4e0b\u9762\u662f\u793a\u4f8b\uff1a<\/p>\n

select\u00a0unix_timestamp();\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0—\u00a01218290027
\nselect\u00a0unix_timestamp(‘2008-08-08’);\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0—\u00a01218124800
\nselect\u00a0unix_timestamp(‘2008-08-08\u00a012:30:00’);\u00a0\u00a0—\u00a01218169800<\/p>\n

select\u00a0from_unixtime(1218290027);\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0—\u00a0‘2008-08-09\u00a021:53:47’
\nselect\u00a0from_unixtime(1218124800);\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0—\u00a0‘2008-08-08\u00a000:00:00’
\nselect\u00a0from_unixtime(1218169800);\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0—\u00a0‘2008-08-08\u00a012:30:00’<\/p>\n

select\u00a0from_unixtime(1218169800,\u00a0‘%Y\u00a0%D\u00a0%M\u00a0%h:%i:%s\u00a0%x’);\u00a0—\u00a0‘2008\u00a08th\u00a0August\u00a012:30:00\u00a02008’<\/p>\n

3.\u00a0MySQL\u00a0\u65f6\u95f4\u6233\uff08timestamp\uff09\u8f6c\u6362\u3001\u589e\u3001\u51cf\u51fd\u6570\uff1a<\/p>\n

timestamp(date)\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0—\u00a0date\u00a0to\u00a0timestamp
\ntimestamp(dt,time)\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0—\u00a0dt\u00a0+\u00a0time
\ntimestampadd(unit,interval,datetime_expr)\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0—
\ntimestampdiff(unit,datetime_expr1,datetime_expr2)\u00a0\u00a0\u00a0—<\/p>\n

\u8bf7\u770b\u793a\u4f8b\u90e8\u5206\uff1a<\/p>\n

select\u00a0timestamp(‘2008-08-08’);\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0—\u00a02008-08-08\u00a000:00:00
\nselect\u00a0timestamp(‘2008-08-08\u00a008:00:00′,\u00a0’01:01:01’);\u00a0\u00a0\u00a0\u00a0—\u00a02008-08-08\u00a009:01:01
\nselect\u00a0timestamp(‘2008-08-08\u00a008:00:00′,\u00a0’10\u00a001:01:01’);\u00a0—\u00a02008-08-18\u00a009:01:01<\/p>\n

select\u00a0timestampadd(day,\u00a01,\u00a0‘2008-08-08\u00a008:00:00’);\u00a0\u00a0\u00a0\u00a0\u00a0—\u00a02008-08-09\u00a008:00:00
\nselect\u00a0date_add(‘2008-08-08\u00a008:00:00′,\u00a0interval\u00a01\u00a0day);\u00a0—\u00a02008-08-09\u00a008:00:00<\/p>\n

MySQL\u00a0timestampadd()\u00a0\u51fd\u6570\u7c7b\u4f3c\u4e8e\u00a0date_add()\u3002<\/p>\n

select\u00a0timestampdiff(year,’2002-05-01′,’2001-01-01′);\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0—\u00a0-1
\nselect\u00a0timestampdiff(day\u00a0,’2002-05-01′,’2001-01-01′);\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0—\u00a0-485
\nselect\u00a0timestampdiff(hour,’2008-08-08\u00a012:00:00′,’2008-08-08\u00a000:00:00’);\u00a0\u00a0—\u00a0-12<\/p>\n

select\u00a0datediff(‘2008-08-08\u00a012:00:00’,\u00a0‘2008-08-01\u00a000:00:00’);\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0—\u00a07<\/p>\n

MySQL\u00a0timestampdiff()\u00a0\u51fd\u6570\u5c31\u6bd4\u00a0datediff()\u00a0\u529f\u80fd\u5f3a\u591a\u4e86\uff0cdatediff()\u00a0\u53ea\u80fd\u8ba1\u7b97\u4e24\u4e2a\u65e5\u671f\uff08date\uff09\u4e4b\u95f4\u76f8\u5dee\u7684\u5929\u6570\u3002
\n\u516d\u3001MySQL\u00a0\u65f6\u533a\uff08timezone\uff09\u8f6c\u6362\u51fd\u6570<\/p>\n

convert_tz(dt,from_tz,to_tz)<\/p>\n

select\u00a0convert_tz(‘2008-08-08\u00a012:00:00’,\u00a0‘+08:00’,\u00a0‘+00:00’);\u00a0—\u00a02008-08-08\u00a004:00:00<\/p>\n

\u65f6\u533a\u8f6c\u6362\u4e5f\u53ef\u4ee5\u901a\u8fc7\u00a0date_add,\u00a0date_sub,\u00a0timestampadd\u00a0\u6765\u5b9e\u73b0\u3002<\/p>\n

select\u00a0date_add(‘2008-08-08\u00a012:00:00’,\u00a0interval\u00a0-8\u00a0hour);\u00a0\u00a0—\u00a02008-08-08\u00a004:00:00
\nselect\u00a0date_sub(‘2008-08-08\u00a012:00:00’,\u00a0interval\u00a0\u00a08\u00a0hour);\u00a0\u00a0—\u00a02008-08-08\u00a004:00:00
\nselect\u00a0timestampadd(hour,\u00a0-8,\u00a0‘2008-08-08\u00a012:00:00’);\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0—\u00a02008-08-08\u00a004:00:00<\/p>\n","protected":false},"excerpt":{"rendered":"

\u5f15\u7528\u5730\u5740\uff1ahttp:\/\/www.cnblogs.com\/redfox241\/archive\/2009\/07\/23\/1529092.html \u4e00\u3001MySQL\u00a0\u83b7\u5f97\u5f53\u524d\u65e5\u671f\u65f6\u95f4\u00a0\u51fd\u6570 1.1\u00a0\u83b7\u5f97\u5f53\u524d\u65e5\u671f+\u65f6\u95f4\uff08date\u00a0+\u00a0time\uff09\u51fd\u6570\uff1anow() mysql>\u00a0select\u00a0now(); +———————+ |\u00a0now()\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0| +———————+ |\u00a02008-08-08\u00a022:20:46\u00a0| +———————+ \u9664\u4e86\u00a0now()\u00a0\u51fd\u6570\u80fd\u83b7\u5f97\u5f53\u524d\u7684\u65e5\u671f\u65f6\u95f4\u5916\uff0cMySQL\u00a0\u4e2d\u8fd8\u6709\u4e0b\u9762\u7684\u51fd\u6570\uff1a \u00a0current_timestamp() ,current_timestamp ,localtime() ,localtime ,localtimestamp\u00a0\u00a0\u00a0\u00a0—\u00a0(v4.0.6) ,localtimestamp()\u00a0\u00a0—\u00a0(v4.0.6) \u8fd9\u4e9b\u65e5\u671f\u65f6\u95f4\u51fd\u6570\uff0c\u90fd\u7b49\u540c\u4e8e\u00a0now()\u3002\u9274\u4e8e\u00a0now()\u00a0\u51fd\u6570\u7b80\u77ed\u6613\u8bb0\uff0c\u5efa\u8bae\u603b\u662f\u4f7f\u7528\u00a0now()\u00a0\u6765\u66ff\u4ee3\u4e0a\u9762\u5217\u51fa\u7684\u51fd\u6570\u3002 1.2\u00a0\u83b7\u5f97\u5f53\u524d\u65e5\u671f+\u65f6\u95f4\uff08date\u00a0+\u00a0time\uff09\u51fd\u6570\uff1asysdate() sysdate()\u00a0\u65e5\u671f\u65f6\u95f4\u51fd\u6570\u8ddf\u00a0now()\u00a0\u7c7b\u4f3c\uff0c\u4e0d\u540c\u4e4b\u5904\u5728\u4e8e\uff1anow()\u00a0\u5728\u6267\u884c\u5f00\u59cb\u65f6\u503c\u5c31\u5f97\u5230\u4e86\uff0c\u00a0sysdate()\u00a0\u5728\u51fd\u6570\u6267\u884c\u65f6\u52a8\u6001\u5f97\u5230\u503c\u3002\u770b\u4e0b\u9762\u7684\u4f8b\u5b50\u5c31\u660e\u767d\u4e86\uff1a mysql>\u00a0select\u00a0now(),\u00a0sleep(3),\u00a0now(); +———————+———-+———————+ |\u00a0now()\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0|\u00a0sleep(3)\u00a0|\u00a0now()\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0| +———————+———-+———————+ |\u00a02008-08-08\u00a022:28:21\u00a0|\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a00\u00a0|\u00a02008-08-08\u00a022:28:21\u00a0| +———————+———-+———————+ mysql>\u00a0select\u00a0sysdate(),\u00a0sleep(3),\u00a0sysdate(); +———————+———-+———————+ |\u00a0sysdate()\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0|\u00a0sleep(3)\u00a0|\u00a0sysdate()\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0| +———————+———-+———————+ |\u00a02008-08-08\u00a022:28:41\u00a0|\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a00\u00a0|\u00a02008-08-08\u00a022:28:44\u00a0| +———————+———-+———————+ \u53ef\u4ee5\u770b\u5230\uff0c\u867d\u7136\u4e2d\u9014\u00a0sleep\u00a03\u00a0\u79d2\uff0c\u4f46\u00a0now()\u00a0\u51fd\u6570\u4e24\u6b21\u7684\u65f6\u95f4\u503c\u662f\u76f8\u540c\u7684\uff1b\u00a0sysdate()\u00a0\u51fd\u6570\u4e24\u6b21\u5f97\u5230\u7684\u65f6\u95f4\u503c\u76f8\u5dee\u00a03\u00a0\u79d2\u3002MySQL\u00a0Manual\u00a0\u4e2d\u662f\u8fd9\u6837\u63cf\u8ff0\u00a0sysdate()\u00a0\u7684\uff1aReturn\u00a0the\u00a0time\u00a0at\u00a0which\u00a0the\u00a0function\u00a0executes\u3002 sysdate()\u00a0\u65e5\u671f\u65f6\u95f4\u51fd\u6570\uff0c\u4e00\u822c\u60c5\u51b5\u4e0b\u5f88\u5c11\u7528\u5230\u3002 2.\u00a0\u83b7\u5f97\u5f53\u524d\u65e5\u671f\uff08date\uff09\u51fd\u6570\uff1acurdate() mysql>\u00a0select\u00a0curdate(); +————+ |\u00a0curdate()\u00a0\u00a0| +————+ |\u00a02008-08-08\u00a0| +————+ … \u7ee7\u7eed\u9605\u8bfb →<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[8],"tags":[19,21,20],"_links":{"self":[{"href":"http:\/\/zduo.me\/blog\/index.php?rest_route=\/wp\/v2\/posts\/46"}],"collection":[{"href":"http:\/\/zduo.me\/blog\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/zduo.me\/blog\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/zduo.me\/blog\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/zduo.me\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=46"}],"version-history":[{"count":2,"href":"http:\/\/zduo.me\/blog\/index.php?rest_route=\/wp\/v2\/posts\/46\/revisions"}],"predecessor-version":[{"id":48,"href":"http:\/\/zduo.me\/blog\/index.php?rest_route=\/wp\/v2\/posts\/46\/revisions\/48"}],"wp:attachment":[{"href":"http:\/\/zduo.me\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=46"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/zduo.me\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=46"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/zduo.me\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=46"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}