锘??xml version="1.0" encoding="utf-8" standalone="yes"?>
use rorely;
create table test(
id int(4) not null unique auto_increment,
name varchar(20) not null,
age int(3) not null,
sex varchar(10錛塶ot null,
address varchar(100)
);
insert into test values(null,'Jim',23,'male','wenming cun 23#');
insert into test values(null,'Jim',23,'male','wenming cun 23#');
insert into test values(null,'Jim',23,'male','wenming cun 23#');
insert into test values(null,'Jim',23,'male','wenming cun 23#');
insert into test values(null,'Jim',23,'male','wenming cun 23#');
select * from test;
]]>
鎴戜滑瑕佹妸鐜板疄涓栫晫涓殑鍚勭淇℃伅杞崲鎴愯綆楁満鑳界悊瑙g殑涓滆タ錛岃繖浜涜漿鎹㈠悗鐨勪俊鎭氨褰㈡垚浜嗘暟鎹備緥 濡傦紝鏌愪漢鐨勫嚭鐢熸棩鏈熸槸“1987騫?鏈?3鏃?#8221;錛屼粬鐨勮韓楂樻槸170鍘樼背錛岀瓑絳夈傛暟鎹笉浠呭寘鎷暟瀛椼佸瓧姣嶃佹枃瀛楀拰鍏朵粬鐗規畩瀛楃緇勬垚鐨勬枃鏈艦寮忕殑鏁版嵁錛岃屼笖榪? 鍖呮嫭鍥懼艦銆佸浘鍍忋佸姩鐢匯佸獎鍍忋佸0闊崇瓑澶氬獟浣撴暟鎹備絾浣跨敤鏈澶氥佹渶鍩烘湰鐨勪粛鐒舵槸鏂囨湰鏁版嵁銆?
1. MySQL鐨勬暟鎹被鍨?
鍦∕ySQL涓湁濡備笅鍑犵鏁版嵁綾誨瀷錛?
錛?錛夋暟鍊煎瀷
鏁板兼槸璇稿32 鎴?53.4 榪欐牱鐨勫箋侻ySQL 鏀寔縐戝琛ㄧず娉曪紝縐戝琛ㄧず娉曠敱鏁存暟鎴栨誕鐐規暟鍚庤窡“e”鎴?#8220;E”銆佷竴涓鍙鳳紙“+”鎴?#8220;-”錛夊拰涓涓暣鏁版寚鏁版潵琛ㄧず銆?.24E+12 鍜?3.47e-1 閮芥槸鍚堟硶鐨勭瀛﹁〃紺烘硶琛ㄧず鐨勬暟銆傝?.24E12 涓嶆槸鍚堟硶鐨勶紝鍥犱負鎸囨暟鍓嶇殑絎﹀彿鏈粰鍑恒?
嫻偣鏁扮敱鏁存暟閮ㄥ垎銆佷竴涓皬鏁扮偣鍜屽皬鏁伴儴鍒嗙粍鎴愩傛暣鏁伴儴鍒嗗拰灝忔暟閮ㄥ垎鍙互鍒嗗埆涓虹┖錛屼絾涓嶈兘鍚屾椂涓虹┖銆?
鏁板煎墠鍙斁涓涓礋鍙?#8220;-”浠ヨ〃紺鴻礋鍊箋?
錛?錛夊瓧絎︼紙涓詫級鍨?
瀛楃鍨嬶紙涔熷彨瀛楃涓插瀷錛岀畝縐頒覆錛夋槸璇稿“Hello, world!”鎴?#8220;涓涓澶村紩璧風殑琛妗?#8221;榪欐牱鐨勫鹼紝鎴栬呮槸鐢佃瘽鍙風爜87398413榪欐牱鐨勫箋傛棦鍙敤鍗曞紩鍙蜂篃鍙敤鍙屽紩鍙峰皢涓插兼嫭璧鋒潵銆?
鍒濆鑰呭線寰鍒嗕笉娓呮暟鍊?7398143鍜屽瓧絎︿覆87398143鐨勫尯鍒傞兘鏄暟瀛楀晩錛屾庝箞涓 涓鐢ㄦ暟鍊煎瀷錛屼竴涓鐢ㄥ瓧絎﹀瀷鍛紵鍏抽敭灝卞湪浜庯細鏁板煎瀷鐨?7398143鏄鍙備笌璁$畻鐨勶紝姣斿瀹冩槸閲戣瀺涓殑涓涓揣嬈炬婚錛涜屽瓧絎﹀瀷鐨?7398143鏄笉 鍙備笌璁$畻鐨勶紝鍙槸琛ㄧず鐢佃瘽鍙風爜錛岃繖鏍風殑榪樻湁琛楅亾鍙風爜銆侀棬鐗屽彿鐮佺瓑絳夛紝瀹冧滑閮戒笉鍙備笌璁$畻銆?
錛?錛夋棩鏈熷拰鏃墮棿鍨?
鏃ユ湡鍜屾椂闂存槸涓浜涜濡?#8220;2006-07-12”鎴?#8220;12:30:43”榪欐牱鐨勫箋侻ySQL榪樻敮鎸佹棩鏈?鏃墮棿鐨勭粍鍚堬紝濡?#8220;2006-07-12 12:30:43”銆?
錛?錛塏ULL鍊?
NULL琛ㄧず鏈煡鍊箋傛瘮濡傚~鍐欒〃鏍間腑閫氳鍦板潃涓嶆竻妤氱暀絀轟笉濉啓錛岃繖灝辨槸NULL鍊箋?
鎴戜滑鐢–reate Table璇彞鍒涘緩涓涓〃錛堝弬鐪嬪墠闈㈢殑绔犺妭錛夛紝榪欎釜琛ㄤ腑鍖呭惈鍒楃殑瀹氫箟銆備緥濡傛垜浠湪鍓嶉潰鍒涘緩浜嗕竴涓猨oke琛紝榪欎釜琛ㄤ腑鏈塩ontent鍜寃riter涓や釜鍒楋細
瀹氫箟涓涓垪鐨勮娉曞涓嬶細
鍏朵腑鍒楀悕鐢眂ol_name 緇欏嚭銆傚垪鍚嶅彲鏈澶氬寘鍚?4涓瓧絎︼紝瀛楃鍖呮嫭瀛楁瘝銆佹暟瀛椼佷笅鍒掔嚎鍙婄編鍏冪鍙楓傚垪鍚嶅彲浠ュ悕瀛椾腑鍚堟硶鐨勪換浣曠鍙鳳紙鍖呮嫭鏁板瓧錛夊紑澶淬備絾鍒楀悕涓嶈兘瀹屽叏鐢辨暟瀛楃粍鎴愶紝鍥? 涓洪偅鏍峰彲鑳戒嬌鍏朵笌鏁版嵁鍒嗕笉寮銆侻ySQL淇濈暀璇稿SELECT銆丏ELETE鍜孋REATE榪欐牱鐨勮瘝錛岃繖浜涜瘝涓嶈兘鐢ㄥ仛鍒楀悕錛屼絾鏄嚱鏁板悕錛堝POS 鍜孧IN錛夋槸鍙互浣跨敤鐨勩?
鍒楃被鍨媍ol_type琛ㄧず鍒楀彲瀛樺偍鐨勭壒瀹氬箋傚垪綾誨瀷璇存槑絎﹁繕鑳借〃紺哄瓨鏀懼湪鍒椾腑鐨勫肩殑鏈澶ч暱 搴︺傚浜庢煇浜涚被鍨嬶紝鍙敤涓涓暟鍊兼槑紜湴璇存槑鍏墮暱搴︺傝屽彟澶栦竴浜涘鹼紝鍏墮暱搴︾敱綾誨瀷鍚嶈暣鍚備緥濡傦紝CHAR(10) 鏄庣‘鎸囧畾浜?0涓瓧絎︾殑闀垮害錛岃孴INYBLOB鍊奸殣鍚渶澶ч暱搴︿負255涓瓧絎︺傛湁鐨勭被鍨嬭鏄庣鍏佽鎸囧畾鏈澶х殑鏄劇ず瀹藉害錛堝嵆鏄劇ず鍊兼椂浣跨敤澶氬皯涓瓧絎︼級銆傛誕 鐐圭被鍨嬪厑璁告寚瀹氬皬鏁頒綅鏁幫紝鎵浠ヨ兘鎺у埗嫻偣鏁扮殑綺懼害鍊間負澶氬皯銆?
鍙互鍦ㄥ垪綾誨瀷涔嬪悗鎸囧畾鍙夌殑綾誨瀷璇存槑灞炴э紝浠ュ強鎸囧畾鏇村鐨勫父瑙佸睘鎬с傚睘鎬ц搗淇グ綾誨瀷鐨勪綔鐢紝騫舵洿鏀瑰叾澶勭悊鍒楀肩殑鏂瑰紡錛屽睘鎬ф湁浠ヤ笅綾誨瀷錛?
錛?錛変笓鐢ㄥ睘鎬х敤浜庢寚瀹氬垪銆備緥濡傦紝UNSIGNED 灞炴у彧閽堝鏁村瀷錛岃孊INARY灞炴у彧鐢ㄤ簬CHAR 鍜孷ARCHAR銆?
錛?錛夐氱敤灞炴ч櫎灝戞暟鍒椾箣澶栧彲鐢ㄤ簬浠繪剰鍒椼傚彲浠ユ寚瀹歂ULL 鎴朜OT NULL 浠ヨ〃紺烘煇涓垪鏄惁鑳藉瀛樻斁NULL銆傝繕鍙互鐢―EFAULT錛宒ef_value 鏉ヨ〃紺哄湪鍒涘緩涓涓柊琛屼絾鏈槑紜粰鍑鴻鍒楃殑鍊兼椂錛岃鍒楀彲璧嬩簣鍊糳ef_value銆俤ef_value 蹇呴』涓轟竴涓父閲忥紱瀹冧笉鑳芥槸琛ㄨ揪寮忥紝涔熶笉鑳藉紩鐢ㄥ叾浠栧垪銆備笉鑳藉BLOB 鎴朤EXT 鍒楁寚瀹氱己鐪佸箋?
濡傛灉鎯崇粰鍑哄涓垪鐨勪笓鐢ㄥ睘鎬э紝鍙寜浠繪剰欏哄簭鎸囧畾瀹冧滑錛屽彧瑕佸畠浠窡鍦ㄥ垪綾誨瀷涔嬪悗銆侀氱敤灞炴т箣鍓嶅嵆鍙傜被浼煎湴錛屽鏋滈渶瑕佺粰鍑哄涓氱敤灞炴э紝涔熷彲鎸変換鎰忛『搴忕粰鍑哄畠浠紝鍙灝嗗畠浠斁鍦ㄥ垪綾誨瀷鍜屽彲鑳界粰鍑虹殑鍒椾笓鐢ㄥ睘鎬т箣鍚庡嵆鍙?
2. MySQL鐨勫垪錛堝瓧孌碉級綾誨瀷
鏁版嵁搴撲腑鐨勬瘡涓〃閮芥槸鐢變竴涓垨澶氫釜鍒楋紙瀛楁錛夋瀯鎴愮殑銆傚湪鐢–REATE TABLE璇彞鍒涘緩涓涓〃鏃訛紝瑕佷負姣忓垪錛堝瓧孌碉級鎸囧畾涓涓被鍨嬨傚垪錛堝瓧孌碉級鐨勭被鍨嬫瘮鏁版嵁綾誨瀷鏇翠負緇嗗寲錛屽畠綺劇‘鍦版弿榪頒簡緇欏畾琛ㄥ垪錛堝瓧孌碉級鍙兘鍖呭惈鐨勫肩殑縐嶇被錛屽鏄惁甯﹀皬鏁般佹槸鍚︽枃瀛楀緢澶氥?
MySQL鏈夋暣鏁板拰嫻偣鏁板肩殑鍒楃被鍨嬶紝濡傝〃1鎵紺恒傛暣鏁板垪綾誨瀷鍙互鏈夌鍙蜂篃鍙棤絎﹀彿銆傛湁涓縐嶇壒孌婄殑灞炴у厑璁告暣鏁板垪鍊艱嚜鍔ㄧ敓鎴愶紝榪欏闇瑕佸敮涓搴忓垪鎴栨爣璇嗗彿鐨勫簲鐢ㄧ郴緇熸潵璇存槸闈炲父鏈夌敤鐨勩?
綾誨瀷 |
璇存槑 |
TINYINT | 闈炲父灝忕殑鏁存暟 |
SMALLINT | 杈冨皬鏁存暟 |
MEDIUMINT | 涓瓑澶у皬鏁存暟 |
INT | 鏍囧噯鏁存暟 |
BIGINT | 杈冨ぇ鏁存暟 |
FLOAT | 鍗曠簿搴︽誕鐐規暟 |
DOUBLE | 鍙岀簿搴︽誕鐐規暟 |
DECIMAL | 涓涓覆鐨勬誕鐐規暟 |
姣忕鏁板肩被鍨嬬殑鍚嶇О鍜屽彇鍊艱寖鍥村琛?鎵紺恒?
綾誨瀷璇存槑 |
鍙栧艱寖鍥?/strong> |
TINYINT[(M)] | 鏈夌鍙峰鹼細-128 鍒?27錛? 27 鍒?7 - 1錛? 鏃犵鍙峰鹼細0鍒?55錛? 鍒?8 - 1錛? |
SMALLINT[(M)] | 鏈夌鍙峰鹼細-32768 鍒?2767錛? 215 鍒?15 - 1錛? 鏃犵鍙峰鹼細0鍒?5535錛? 鍒?1 6 - 1錛? |
MEDIUMINT[(M)] | 鏈夌鍙峰鹼細-8388608 鍒?388607錛? 22 3 鍒?2 3 - 1 錛? 鏃犵鍙峰鹼細0鍒?6777215錛? 鍒?2 4 - 1錛? |
INT[(M)] | 鏈夌鍙峰鹼細-2147683648 鍒?147683647錛? 231 鍒?31- 1錛? 鏃犵鍙峰鹼細0鍒?294967295錛? 鍒?32 - 1錛? |
BIGINT[(M)] | 鏈夌鍙峰鹼細-9223372036854775808 鍒?223373036854775807錛? 263鍒?63-1錛? 鏃犵鍙峰鹼細0鍒?8446744073709551615錛?鍒?64 – 1錛? |
FLOAT[(M, D)] | 鏈灝忛潪闆跺鹼細±1.175494351E - 38 |
DOUBLE[(M,D)] | 鏈灝忛潪闆跺鹼細±2.2250738585072014E - 308 |
DECIMAL (M, D) | 鍙彉錛涘叾鍊肩殑鑼冨洿渚濊禆浜嶮 鍜孌 |
綾誨瀷璇存槑 |
瀛樺偍闇姹?/strong> |
TINYINT[(M)] | 1瀛楄妭 |
SMALLINT[(M)] | 2瀛楄妭 |
MEDIUMINT[(M)] | 3瀛楄妭 |
INT[(M)] | 4瀛楄妭 |
BIGINT[(M)] | 8瀛楄妭 |
FLOAT[(M, D)] | 4瀛楄妭 |
DOUBLE[(M, D)] | 8瀛楄妭 |
DECIMAL (M, D) | M瀛楄妭錛圡ySQL < 3.23錛夛紝M+2瀛楄妭錛圡ySQL > 3.23 錛?/td> |
MySQL鎻愪緵浜嗕簲縐嶆暣鍨嬶細 TINYINT銆丼MALLINT銆丮EDIUMINT銆両NT鍜孊IGINT銆侷NT涓篒NTEGER鐨勭緝鍐欍傝繖浜涚被鍨嬪湪鍙〃紺虹殑鍙栧艱寖鍥翠笂鏄笉鍚岀殑銆? 鏁存暟鍒楀彲瀹氫箟涓篣NSIGNED浠庤岀鐢ㄨ礋鍊鹼紱榪欎嬌鍒楃殑鍙栧艱寖鍥翠負0浠ヤ笂銆傚悇縐嶇被鍨嬬殑瀛樺偍閲忛渶姹備篃鏄笉鍚岀殑銆傚彇鍊艱寖鍥磋緝澶х殑綾誨瀷鎵闇鐨勫瓨鍌ㄩ噺杈冨ぇ銆?/p>
MySQL 鎻愪緵涓夌嫻偣綾誨瀷錛? FLOAT銆丏OUBLE鍜孌ECIMAL銆備笌鏁村瀷涓嶅悓錛屾誕鐐圭被鍨嬩笉鑳芥槸UNSIGNED鐨勶紝鍏跺彇鍊艱寖鍥翠篃涓庢暣鍨嬩笉鍚岋紝榪欑涓嶅悓涓嶄粎鍦ㄤ簬榪欎簺綾誨瀷鏈夋渶澶? 鍊鹼紝鑰屼笖榪樻湁鏈灝忛潪闆跺箋傛渶灝忓兼彁渚涗簡鐩稿簲綾誨瀷綺懼害鐨勪竴縐嶅害閲忥紝榪欏浜庤褰曠瀛︽暟鎹潵璇存槸闈炲父閲嶈鐨勶紙褰撶劧錛屼篃鏈夎礋鐨勬渶澶у拰鏈灝忓鹼級銆?
鍦ㄩ夋嫨浜嗘煇縐嶆暟鍊肩被鍨嬫椂錛屽簲璇ヨ冭檻鎵瑕佽〃紺虹殑鍊肩殑鑼冨洿錛屽彧闇閫夋嫨鑳借鐩栬鍙栧肩殑鑼冨洿鐨勬渶灝忕被 鍨嬪嵆鍙傞夋嫨杈冨ぇ綾誨瀷浼氬絀洪棿閫犳垚嫻垂錛屼嬌琛ㄤ笉蹇呰鍦板澶э紝澶勭悊璧鋒潵娌℃湁閫夋嫨杈冨皬綾誨瀷閭f牱鏈夋晥銆傚浜庢暣鍨嬪鹼紝濡傛灉鏁版嵁鍙栧艱寖鍥磋緝灝忥紝濡備漢鍛樺勾榫勬垨鍏勫紵濮愬 鏁幫紝鍒橳INYINT鏈鍚堥傘侻EDIUMINT鑳藉琛ㄧず鏁扮櫨涓囩殑鍊煎茍涓斿彲鐢ㄤ簬鏇村綾誨瀷鐨勫鹼紝浣嗗瓨鍌ㄤ唬浠瘋緝澶с侭IGINT鍦ㄥ叏閮ㄦ暣鍨嬩腑鍙栧艱寖鍥存渶澶э紝鑰? 涓旈渶瑕佺殑瀛樺偍絀洪棿鏄〃紺鴻寖鍥存澶х殑鏁村瀷INT綾誨瀷鐨勪袱鍊嶏紝鍥犳鍙湪紜疄闇瑕佹椂鎵嶇敤銆傚浜庢誕鐐瑰鹼紝DOUBLE鍗犵敤FLOAT鐨勪袱鍊嶇┖闂淬傞櫎闈炵壒鍒渶瑕侀珮綺? 搴︽垨鑼冨洿鏋佸ぇ鐨勫鹼紝涓鑸簲浣跨敤鍙敤涓鍗婂瓨鍌ㄤ唬浠風殑FLOAT鍨嬫潵琛ㄧず鏁版嵁銆?
鍦ㄥ畾涔夋暣鍨嬪垪鏃訛紝鍙互鎸囧畾鍙夌殑鏄劇ず灝哄M銆傚鏋滆繖鏍鳳紝M搴旇鏄竴涓? 鍒?55鐨勬暣鏁般傚畠琛ㄧず鐢ㄦ潵鏄劇ず鍒椾腑鍊肩殑瀛楃鏁般備緥濡傦紝MEDIUMINT(4)鎸囧畾浜嗕竴涓叿鏈?涓瓧絎︽樉紺哄搴︾殑MEDIUMINT鍒椼傚鏋滃畾涔変簡涓涓? 娌℃湁鏄庣‘瀹藉害鐨勬暣鏁板垪錛屽皢浼氳嚜鍔ㄥ垎閰嶇粰瀹冧竴涓己鐪佺殑瀹藉害銆傜己鐪佸間負姣忕綾誨瀷鐨?#8220;鏈闀?#8221;鍊肩殑闀垮害銆傚鏋滄煇涓壒瀹氬肩殑鍙墦鍗拌〃紺洪渶瑕佷笉姝涓瓧絎︼紝鍒欐樉紺哄畬鍏? 鐨勫鹼紱涓嶄細灝嗗兼埅鏂互閫傚悎M涓瓧絎︺?
瀵規瘡縐嶆誕鐐圭被鍨嬶紝鍙寚瀹氫竴涓渶澶х殑鏄劇ず灝哄M 鍜屽皬鏁頒綅鏁癉銆侻 鐨勫煎簲璇ュ彇1 鍒?55銆侱鐨勫煎彲涓? 鍒? 0錛屼絾鏄笉搴斿ぇ浜嶮 - 2錛堝鏋滅啛鎮塐DBC 鏈錛屽氨浼氱煡閬揗 鍜孌 瀵瑰簲浜嶰DBC 姒傚康鐨?#8220;綺懼害”鍜?#8220;灝忔暟鐐逛綅鏁?#8221;錛夈侻鍜孌瀵笷LOAT鍜孌OUBLE 閮芥槸鍙夌殑錛屼絾瀵逛簬DECIMAL鏄繀欏葷殑銆傚湪閫夐」M 鍜孌鏃訛紝濡傛灉鐪佺暐浜嗗畠浠紝鍒欎嬌鐢ㄧ己鐪佸箋?
2.2瀛楃涓插垪綾誨瀷
MySQL鎻愪緵浜嗗嚑縐嶅瓨鏀懼瓧絎︽暟鎹殑涓茬被鍨嬶紝鍏剁被鍨嬪涓嬶細
綾誨瀷鍚?/strong> |
璇存槑 |
CHAR | 瀹氶暱瀛楃涓?/td> |
VARCHAR | 鍙彉闀垮瓧絎︿覆 |
TINYBLOB | 闈炲父灝忕殑BLOB錛堜簩榪涘埗澶у璞★級 |
BLOB | 灝廈LOB |
MEDIUMBLOB | 涓瓑鐨凚LOB |
LONGBLOB | 澶LOB |
TINYTEXT | 闈炲父灝忕殑鏂囨湰涓?/td> |
TEXT | 灝忔枃鏈覆 |
MEDIUMTEXT | 涓瓑鏂囨湰涓?/td> |
LONGTEXT | 澶ф枃鏈覆 |
ENUM | 鏋氫婦錛涘垪鍙祴浜堟煇涓灇涓炬垚鍛?/td> |
SET | 闆嗗悎錛涘垪鍙祴浜堝涓泦鍚堟垚鍛?/td> |