瀛楃闆嗘敮鎸伮?/p>
MySQL4.1浠ュ悗鐨勭増鏈瀛楃闆嗙殑鏀寔鍏鋒湁浠ヤ笅鏂板鍔熻兘錛?/p>
鏀寔鏈嶅姟鍣ㄥ悓鏃朵嬌鐢ㄥ縐嶅瓧絎﹂泦銆?/p>
鍏佽鍦ㄦ湇鍔″櫒錛屾暟鎹簱錛屾暟鎹〃錛屾暟鎹垪絳夊綰у埆涓婅緗笉鍚岀殑瀛楃闆嗐?/p>
鏈嶅姟鍣ㄧ殑榛樿瀛楃闆嗗湪緙栬瘧鏃墮夊畾錛屼絾鍙湪鍚姩鏈嶅姟鍣ㄦ椂鐢?-default-character-set閫夐」鏉ユ洿鏀廣?/p>
鐢ˋLTER DATABASE db_name DEFAULT CHARACTER SET charset鏉ヨ緗暟鎹簱瀛楃闆嗐?濡傛灉鍙湁default鍙傛暟錛屽垯浣跨敤鏈嶅姟鍣ㄧ殑瀛楃闆嗐?/p>
鐢–REATE TABLE table_name(...) CHARACTER SET = charset璁劇疆鏁版嵁琛ㄥ瓧絎﹂泦銆傚鏋渃harset涓篸efault錛屽垯浣跨敤鏁版嵁琛ㄦ墍鍦ㄦ暟鎹簱鐨勫瓧絎﹂泦浣滀負鏁版嵁琛ㄧ殑瀛楃闆嗐?/p>
鍦ㄦ暟鎹垪涓紝鍙敤CHARACTER SET charset灞炴ф潵璁劇疆鏁版嵁鍒楃殑瀛楃闆嗐俢harset涓嶈兘鏄痙efault錛屽鏋滄病鏈夎灞炴э紝鍒欓粯璁や嬌鐢ㄦ暟鎹〃鐨勫瓧絎﹂泦銆傚厑璁歌緗瓧絎﹂泦鐨勬暟鎹垪鏈塩har錛寁archar(涓嶅甫binary灞炴?鍙奣EXT綾誨瀷銆?/p>
鐢╛charset str杞崲瀛楃涓插父鏁扮殑瀛楃闆嗐傚錛歘utf8 'mysql'錛宊latinl 'oracle'銆傝鏂規硶鍙傜敤浜庢嫭鍦ㄥ紩鍙峰唴鐨勫瓧絎︿覆錛屽叾瀹冨崄鍏繘鍒跺父鏁?銆佸瓧絎︿覆琛ㄨ揪寮忕瓑鍙敤CONVERT()鍑芥暟榪涜杞崲錛屽錛歋ELECT CONVERT( str USING charset)銆?/p>
閫氳繃MySQL鎻愪緵鐨勫嚱鏁板彲榪涜瀛楃闆嗚漿鎹㈠拰鏌ヨ銆?/p>
鏂板鐨凜OLLATE鎿嶄綔絎︿嬌鎴戜滑鍙寜鏌愪竴縐嶅瓧絎﹂泦鐨勬帓搴忛『搴忔潵澶勭悊鍙︿竴縐嶅瓧絎﹂泦鐨勬暟鎹傚錛歋ELECT a from t ORDER BY a COLLATE utf-8錛?/p>
鐢⊿HOW CHARACTER SET鍛戒護鍙樉紺烘湇鍔″櫒鏀寔鐨勫瓧絎﹂泦鍒楄〃銆?/p>
褰撴湇鍔″櫒杞崲鍒板彟涓縐嶅瓧絎﹂泦鏃訛紝浼氳嚜鍔ㄥ绱㈠紩榪涜閲嶆柊鎺掑簭銆?/p>
閫氳繃UTF-8鍜孶CS2瀛楃闆嗘彁渚涗簡Unicode鏀寔銆?/p>
MySQL鐜板湪榪樹笉鏀寔錛?,鍦ㄥ悓涓涓瓧絎︿覆閲屾販鐢ㄤ笉鍚屽瓧絎﹂泦鐨勫瓧絎︼紱2,鍦ㄥ悓涓涓暟鎹垪閲屾販鐢ㄤ笉鍚岀殑瀛楃闆嗐?/p>
聽
鍚勭駭瀛楃闆嗙殑鏌ヨ鏂規硶
鏈嶅姟鍣ㄧ駭
SHOW CHARACTER SET錛涘彲鏌ュ嚭鍙緵浣跨敤鐨勬墍鏈夊瓧絎﹂泦銆?br />SHOW VARIABLES LIKE 'character_set'錛涘彲鏌ュ嚭鏈嶅姟鍣ㄧ殑榛樿瀛楃闆嗐?br />
鍙煡鍑烘暟鎹簱綰х殑瀛楃闆嗐?/p>
SHOW CREATE DATABASE db_name錛?br />
涓ゆ潯鍛戒護鍙煡鍑烘暟鎹〃鐨勫瓧絎﹂泦銆?/p>
SHOW CREATE TABLE table_name錛?br />SHOW TABLE STATUS LIKE 'table_name'
浠ヤ笅鍑犲懡浠ゅ彲鏌ュ嚭鏁版嵁鍒楃殑瀛楃闆嗭細
DESCRIBE table_name;
SHOW COLUMNS FROM table_name;
SHOW CREATE TABLE table_name;
鐢–HARSET()鍑芥暟鍙‘瀹氱壒瀹氬瓧絎︿覆錛屽瓧絎︿覆琛ㄨ揪寮忔垨鏁版嵁鍒楀肩浉鍏寵仈鐨勫瓧絎︿覆鐨勫瓧絎﹂泦銆傚錛歋ELECT CHARSET(str)銆?/p>
鏁板煎瀷鐨勫垪綾誨瀷鍖呮嫭鏁村瀷鍜屾誕鐐瑰瀷涓ゅぇ綾匯?/p>
鏁版嵁鍒楃被鍨?/th> | 瀛樺偍絀洪棿 | 鎻忚堪 |
---|---|---|
TINYINT | 1瀛楄妭 | 闈炲父灝忕殑姝f暣鏁幫紝甯︾鍙鳳細-128~127錛屼笉甯︾鍙鳳細0~255 |
SMALLINT | 2瀛楄妭 | 灝忔暣鏁幫紝甯︾鍙鳳細-32768~32767錛屼笉甯︾鍙鳳細0~65535 |
MEDIUMINT | 3瀛楄妭 | 涓瓑澶у皬鐨勬暣鏁幫紝甯︾鍙鳳細-8388608~8388607錛屼笉甯︾鍙鳳細0~16777215 |
INT | 4瀛楄妭 | 鏍囧噯鏁存暟錛屽甫絎﹀彿錛?2147483648~2147483647錛屼笉甯︾鍙鳳細0~4294967295 |
BIGINT | 8瀛楄妭 | 澶ф暣鏁幫紝甯︾鍙鳳細-9223372036854775808~9233372036854775807錛屼笉甯︾鍙鳳細0~18446744073709551615 |
FLOAT | 4瀛楄妭 | 鍗曠簿搴︽誕鐐規暟錛屾渶灝忛潪闆跺鹼細+-1.175494351E-38錛屾渶澶ч潪闆跺鹼細+-3.402823466E+38 |
DOUBLE | 8瀛楄妭 | 鍙岀簿搴︽誕鐐規暟錛屾渶灝忛潪闆跺鹼細+-2.2250738585072014E-308錛屾渶澶ч潪闆跺鹼細+-1.7976931348623157E+308 |
DECIMAL | M+2瀛楄妭 | 浠ュ瓧絎︿覆褰㈠紡琛ㄧず鐨勬誕鐐規暟錛屽畠鐨勫彇鍊艱寖鍥村彲鍙橈紝鐢盡鍜孌鐨勫煎喅瀹氥?/td> |
MySQL鏈変簲縐嶆暣鍨嬫暟鎹垪綾誨瀷錛屽嵆TINYINT錛孲MALLINT錛孧EDIUMINT錛孖NT鍜孊IGINT銆傚畠浠箣闂寸殑鍖哄埆鏄彇鍊艱寖鍥翠笉鍚岋紝瀛樺偍絀洪棿涔熷悇涓嶇浉鍚屻傚湪鏁村瀷鏁版嵁鍒楀悗鍔犱笂UNSIGNED灞炴у彲浠ョ姝㈣礋鏁幫紝鍙栧間粠0寮濮嬨?/p>
澹? 鏄庢暣鍨嬫暟鎹垪鏃訛紝鎴戜滑鍙互涓哄畠鎸囧畾涓樉紺哄搴(1~255)錛屽INT(5)錛屾寚瀹氭樉紺哄搴︿負5涓瓧絎?濡傛灉娌℃湁緇欏畠鎸囧畾鏄劇ず瀹藉害錛孧ySQL浼氫負瀹冩寚 瀹氫竴涓粯璁ゅ箋傛樉紺哄搴﹀彧鐢ㄤ簬鏄劇ず錛屽茍涓嶈兘闄愬埗鍙栧艱寖鍥村拰鍗犵敤絀洪棿錛屽錛欼NT(3)浼氬崰鐢?涓瓧鑺傜殑瀛樺偍絀洪棿錛屽茍涓斿厑璁哥殑鏈澶у間篃涓嶄細鏄?99,鑰屾槸 INT鏁村瀷鎵鍏佽鐨勬渶澶у箋?/p>
MySQL鏈変笁縐嶆誕鐐瑰瀷鏁版嵁鍒楃被鍨嬶紝鍒嗗埆鏄細FLOAT錛孌OUBLE鍜孌ECIMAL銆傛誕鐐圭被鏁版嵁綾誨瀷鏈変竴涓渶澶у彲琛ㄧず鍊煎拰涓涓渶灝忛潪闆跺彲琛ㄧず鍊鹼紝鏈灝忛潪闆跺彲琛ㄧず鍊煎喅瀹氫簡璇ョ被鍨嬬殑綺劇‘搴︺?/p>
MySQL 4.0.2鐗堜箣鍚庯紝FLOAT鍜孌OUBLE閮藉彲浠ユ寚瀹歎NSIGNED灞炴с傚綋鎸囧畾璇ュ睘鎬ф椂錛屽彇鍊艱寖鍥翠笉騫崇Щ鍒版鏁板尯闂達紝鑰屽彧鏄畝鍗曞湴鎶婃誕鐐圭被鍨嬬殑璐熸暟閮ㄤ喚鍘繪帀銆?/p>
嫻? 鐐圭被鍨嬩篃鏈塎(1~255)鍜孌(1~30錛屼笖涓嶈兘澶т簬M-2)銆傚垎鍒〃紺烘樉紺哄搴﹀拰灝忔暟浣嶆暟銆侻鍜孌鍦‵LOAT鍜孌OUBLE涓槸鍙夌殑錛岄粯璁わ紝褰? MySQL鐗堟湰澶т簬3.23.6鏃訛紝FLOAT鍜孌OUBLE綾誨瀷灝嗚淇濆瓨涓虹‖浠舵墍鏀寔鐨勬渶澶х簿搴︺侱ECIMAL鐨凪鍜孌鍊煎湪MySQL3.23.6鍚? 鍙夛紝榛樿D鍊間負0,M鍊間負10銆?
涓? 浜嗚妭鐪佸瓨鍌ㄧ┖闂村拰鎻愰珮鏁版嵁搴撳鐞嗘晥鐜囷紝鎴戜滑搴旀牴鎹簲鐢ㄦ暟鎹殑鍙栧艱寖鍥存潵閫夋嫨涓涓渶閫傚悎鐨勬暟鎹垪綾誨瀷銆傚鏋滄妸涓涓秴鍑烘暟鎹垪鍙栧艱寖鍥寸殑鏁板瓨鍏ヨ鍒楋紝鍒? MySQL灝變細鎴煭璇ュ鹼紝濡傦細鎴戜滑鎶?9999瀛樺叆SMALLINT(3)鏁版嵁鍒楅噷錛屽洜涓篠MALLINT(3)鐨勫彇鍊艱寖鍥存槸-32768~32767錛? 鎵浠ュ氨浼氳鎴煭鎴?2767瀛樺偍銆傛樉紺哄搴?涓嶄細褰卞搷鏁板肩殑瀛樺偍銆傚彧褰卞搷鏄劇ず銆?/p>
瀵逛簬嫻偣鏁版嵁鍒楋紝瀛樺叆鐨勬暟鍊間細琚鍒楀畾涔夌殑灝忔暟浣嶈繘琛屽洓鑸嶄簲鍏ャ傚鎶婁竴涓?.234瀛樺叆FLOAT(6.1)鏁版嵁鍒椾腑錛岀粨鏋滄槸1.2銆?/p>
DECIMAL 涓嶧LOAT鍜孌OUBLE鐨勫尯鍒槸錛欴ECIMAL綾誨瀷鐨勫兼槸浠ュ瓧絎︿覆鐨勫艦寮忚鍌ㄥ瓨璧鋒潵鐨勶紝瀹冪殑灝忔暟浣嶆暟鏄浐瀹氱殑銆傚畠鐨勪紭鐐規槸錛屼笉浼氳薄FLOAT鍜? DOUBLE綾誨瀷鏁版嵁鍒楅偅鏍瘋繘琛屽洓鑸嶄簲鍏ヨ屼駭鐢熻宸紝鎵浠ュ緢閫傚悎鐢ㄤ簬璐㈠姟璁$畻錛涜屽畠鐨勭己鐐規槸錛氱敱浜庡畠鐨勫瓨鍌ㄦ牸寮忎笉鍚岋紝CPU涓嶈兘瀵瑰畠榪涜鐩存帴榪愮畻錛屼粠鑰屽獎 鍝嶈繍綆楁晥鐜囥侱ECIMAL(M錛孌)鎬誨叡瑕佸崰鐢∕+2涓瓧鑺傘?/p>
ZEROFILL灞炴ч傜敤浜庢墍鏈夋暟鍊肩被鏁版嵁鍒楃被鍨嬶紝浣滅敤鏄紝濡傛灉鏁板肩殑瀹藉害灝忎簬瀹氫箟鐨勬樉紺哄搴︼紝鍒欏湪鏁板煎墠濉厖0銆?/p>
UNSIGNED灞炴т笉鍏佽鏁版嵁鍒楀嚭鐜拌礋鏁般?/p>
AUTO_INCREMENT灞炴у彲鐢熸垚鐙竴鏃犱簩鐨勬暟瀛楀簭鍒椼傚彧瀵規暣鏁扮被鐨勬暟鎹垪鏈夋晥銆?/p>
NULL鍜孨OT NULL灞炴ц緗暟鎹垪鏄惁鍙負絀恒?/p>
DEFAULT灞炴у彲涓烘暟鎹垪鎸囧畾榛樿鍊箋?/p>
杞箟搴忓垪 | 鍚箟 |
---|---|
\0 | NUL(ASCII鐨?鍊? |
\' | 鍗曞紩鍙?/td> |
\" | 鍙屽紩鍙?/td> |
\b | 鍚庨絎?/td> |
\n | 鎹㈣絎?/td> |
\r | 鍥炶濺絎?/td> |
\t | 鍒惰〃絎?/td> |
\\ | 鍙嶆枩鏉?/td> |
\Z | Ctrl+Z |