鏁版嵁搴�

涓�銆佹暟鎹簱姒傝堪

1.涓轰粈涔堣蒋浠舵祴璇曞伐绋嬪笀杩橀渶瑕佸涔犳暟鎹簱浠ュ強寮�鍙戞柟闈㈢殑鐭ヨ瘑锛�

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2. 浠�涔堟槸鏁版嵁搴�

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鏁版嵁搴撴槸鎸夌収鏁版嵁鐨勭粨鏋勬潵缁勭粐銆佸瓨鍌ㄣ�佸拰绠＄悊鏁版嵁鐨勪粨搴擄紝绠�鑰岃█涔嬶紝灏辨槸瀛樻斁鏁版嵁鐨勪粨搴撱��姝ｆ槸鍥犱负鏈変簡鏁版嵁搴撳悗锛屾墍鏈変汉鍙互鐩存帴鍦ㄨ繖涓郴缁熶笂鏌ユ壘鏁版嵁鍜屼慨鏀规暟鎹�備緥濡備綘姣忓ぉ浣跨敤浣欓瀹濇煡鐪嬭嚜宸辩殑璐︽埛鏀剁泭锛屽氨鏄粠鍚庡彴鏁版嵁搴撹鍙栨暟鎹悗缁欎綘鐨勩��

鏁版嵁搴撶殑鑻辨枃鍚嶇О鍙獶B(Database)锛岄偅涔堟暟鎹簱閲岄潰鏈変粈涔堜笢涓滃憿锛�

鍏跺疄锛屾暟鎹簱閫氬父鍖呭惈涓�涓垨澶氫釜琛ㄧ粍鎴愩�傚鏋滀綘鐢ㄨ繃Excel锛屽氨浼氱煡閬揈xcel鏄竴寮犱竴寮犵殑浜岀淮琛ㄣ�傛瘡涓〃閮芥槸鐢卞垪鍜岃缁勬垚鐨勶紝鍏朵腑姣忎竴鍒楅兘鐢ㄥ悕瀛楁潵鏍囪瘑鍑烘潵銆傚悓鏍风殑锛屾暟鎹簱閲屽瓨鏀剧殑涔熸槸涓�寮犱竴寮犵殑琛紝鍙笉杩囧悇涓〃涔嬮棿鏄湁鑱旂郴鐨勩�傛墍浠ワ紝绠�鍗曟潵璇达細鏁版嵁搴�=澶氬紶琛�+鍚勮〃涔嬮棿鐨勫叧绯�

鍏跺疄鏁版嵁搴撴槸閫昏緫涓婄殑姒傚康锛屽畠鏄竴鍫嗕簰鐩稿叧鑱旂殑鏁版嵁锛屾斁鍦ㄧ墿鐞嗗疄浣撲笂锛屾槸涓�鍫嗗啓鍦ㄧ鐩樹笂鐨勬枃浠讹紝鏂囦欢涓湁鏁版嵁銆傝繖浜涙渶鍩虹鐨勬暟鎹粍鎴愪簡琛�(table)銆�

3. 甯歌鏁版嵁搴�

Oracle鏄渶鎸ｉ挶鐨勬暟鎹簱锛屽嚭鑷敳楠ㄦ枃鍏徃锛屽競鍦哄崰鏈夌巼闈炲父楂橈紝鍔熻兘闈炲父寮哄ぇ锛岃涓�浜涘ぇ鍨嬩紒涓氾紝鐢典俊锛岄摱琛岋紝璇佸埜鍏徃銆侀噾铻嶅叕鍙告墍浣跨敤锛屽競鍦哄崰鏈夌巼绗竴銆�

MySQL鏄竴涓叧绯诲瀷鏁版嵁搴撶鐞嗙郴缁燂紝鐢辩憺鍏窶ySQL AB 鍏徃寮�鍙戯紝鐩墠灞炰簬 Oracle 鏃椾笅浜у搧銆侻ySQL 鏄渶娴佽鐨勫叧绯诲瀷鏁版嵁搴撶鐞嗙郴缁熶箣涓�锛屽湪 WEB 搴旂敤鏂归潰锛孧ySQL鏄渶濂界殑 RDBMS (Relational Database Management System锛屽叧绯绘暟鎹簱绠＄悊绯荤粺) 搴旂敤杞欢銆侻ySQL鐩墠鏈�娴佽鐨勫紑婧愭暟鎹簱锛岃鐢查鏂囧叕鍙告墍鍗犵敤锛屽▉鑳佺潃鑰佸ぇOracle鐨勫湴浣嶏紝寮�婧愶紝鍏嶈垂锛屾敮鎸佸骞冲彴锛岀畝鍗曟槗瀛︽槗鎿嶄綔锛屽競鍦哄崰鏈夌巼绗簩銆�

SQLServer鏄井杞紑鍙戠殑鏁版嵁搴擄紝閽堝鏈嶅姟鍣紝浠呮敮鎸乄indows鎿嶄綔绯荤粺锛屽彿绉版槸windows涓婃渶濂界敤鐨勬暟鎹簱銆傛暟鎹簱鐨勫ぉ涓嬩笉浠呬粎鏄疢ySQL鍜孫racle鐨勶紝SQLServer涔熸鍦ㄦ參鎱㈠礇璧凤紝寰蒋缃戠綏浜嗕笉灏戞暟鎹簱鐨勪笓瀹讹紝鎺ㄥ嚭浜嗕笉灏戦噸纾呭姛鑳姐��

MongoDB锛屾渶濂界敤鐨勬枃妗ｅ瀷鏁版嵁搴擄紝鏄疦OSQL绫诲瀷鏁版嵁搴撶殑棰嗗鑰呬箣涓�锛屼篃鏄綋鍓嶆渶鎴愬姛鐨凬oSQL绫诲瀷鏁版嵁搴擄紝鏁版嵁瀛樺偍鏍煎紡閲囩敤JSON褰㈠紡锛岄潪甯哥伒娲汇��

Redis锛屾渶濂界殑鍐呭瓨绾ф暟鎹簱锛屾煡璇㈡晥鐜囨瀬楂橈紝骞朵笖鍦≧edis 3.0涔嬪悗锛屾敮鎸佸绉嶆暟鎹被鍨嬶紝String锛孲et锛孡ist锛孒ash绛夌被鍨嬶紝寮�濮嬫敮鎸侀泦缇わ紝寮ヨˉ浜嗚嚜韬煭鏉裤�傛槸鐩墠鍋氱紦瀛樻渶娴佽鐨勬暟鎹簱

Neo4J锛屾渶濂界殑鍥惧舰鍖栨暟鎹簱锛屾祦琛岃瘽杈冧綆锛屼絾鏄浘褰㈠寲鏁版嵁搴撶殑缁濆棰嗗鑰呫��

SQLite锛屾渶娴佽鐨勫祵鍏ュ紡鏁版嵁搴擄紝鍗犻鎵嬫満琛屼笟鐨勭粷瀵归瀵艰�呭湴浣嶏紝Android鍜孖OS涓ゅぇ鎵嬫満绯荤粺锛岄兘鍐呭祵浜哠QLite鏁版嵁搴擄紝SQLite鏄竴涓畬鏁寸殑鍏崇郴鍨嬫暟鎹簱锛屾敮鎸佹爣鍑哠QL锛屾敮鎸佷簨鍔℃搷浣滐紝绋嬪簭鍖呴潪甯稿皬锛屾槸宓屽叆寮忚澶囩殑鏈�浣抽�夋嫨銆�

鍚勪釜鏁版嵁搴撹蒋浠剁殑浣跨敤宸埆澶у悓灏忓紓锛屼絾鏄洜涓篗ySQL鏄紑婧愮殑锛屾垚涓哄悇澶у叕鍙镐娇鐢ㄧ殑涓绘祦锛岄潰璇曚篃涓昏浠ySQL涓轰富銆�

4.鏁版嵁搴撳拰SQL鏄粈涔堝叧绯伙紵

缁撴瀯鍖栨煡璇㈣瑷�(Structured Query Language)绠�绉癝QL锛屾槸涓�绉嶇壒娈婄洰鐨勭殑缂栫▼璇█锛屾槸涓�绉嶆暟鎹簱鏌ヨ鍜岀▼搴忚璁¤瑷�锛岀敤浜庡瓨鍙栨暟鎹互鍙婃煡璇€�佹洿鏂板拰绠＄悊鍏崇郴鏁版嵁搴撶郴缁燂紱鍚屾椂涔熸槸鏁版嵁搴撹剼鏈枃浠剁殑鎵╁睍鍚嶃��

鏁版嵁搴撻噷闈㈡斁鐫�鏁版嵁锛岃�孲QL鏄敤鏉ユ搷浣滄暟鎹簱閲屾暟鎹殑璇█锛堝伐鍏凤級銆�

渚嬪鏈変竴纰楃背楗紙纰楀氨鏄痬ysql锛岄噷闈㈡斁鐨勭背鏄暟鎹級锛屼綘瑕佸悆纰楅噷鐨勭背楗紝鎷夸粈涔堝悆锛熸嬁绛峰瓙锛坰ql锛夈�傜敤绛峰瓙锛坰ql锛夋搷浣滅閲岋紙mysql锛夌殑绫抽キ锛堟暟鎹級

浜屻�丮ySQL鏁版嵁搴撶殑瀹夎閰嶇疆

澶ч鑱奙ySQL

涓夈�丼QL璇彞鍒嗙被

3.1. DDL-鏁版嵁搴撳畾涔夎瑷�

3.1.1. 姒傚康鍙婁綔鐢�

database defination language 鏁版嵁搴撳畾涔夎瑷�锛岀敤浜庡畾涔夋暟鎹簱锛岀敤浜庡畾涔夎〃缁撴瀯

3.1.2. 琛ㄤ腑瀛楁鍩烘湰鏁版嵁绫诲瀷

MySQL鏀寔澶氱绫诲瀷锛屽ぇ鑷村彲浠ュ垎涓轰笁绫伙細鏁板�笺�佹棩鏈�/鏃堕棿鍜屽瓧绗︿覆(瀛楃)绫诲瀷

涓�涓眽瀛楀崰澶氬皯闀垮害涓庣紪鐮佹湁鍏筹細

UTF锛�8锛氫竴涓眽瀛楋紳3涓瓧鑺�

GBK锛氫竴涓眽瀛楋紳2涓瓧鑺�

varchar(n) 琛ㄧず n 涓瓧绗︼紝鏃犺姹夊瓧鍜岃嫳鏂囷紝Mysql 閮借兘瀛樺叆 n 涓瓧绗︼紝浠呮槸瀹為檯瀛楄妭闀垮害鏈夋墍鍖哄埆

3.1.3. 鏁版嵁搴撹鍙ユ搷浣�

鍦ㄧ櫥闄� MySQL 鏈嶅姟鍚庯紝浣跨敤 create 鍛戒护鍒涘缓鏁版嵁搴擄紝璇硶濡備笅:

CREATE DATABASE 鏁版嵁搴撳悕;

//鍒涘缓绗竴涓暟鎹簱 mydb1create database mydb1

鍦ㄥ垹闄ゆ暟鎹簱杩囩▼涓紝鍔″繀瑕佸崄鍒嗚皑鎱庯紝鍥犱负鍦ㄦ墽琛屽垹闄ゅ懡浠ゅ悗锛屾墍鏈夋暟鎹皢浼氭秷澶便�傝娉曪細

//鍒犻櫎鍒涘缓鐨勬暟鎹簱drop database mydb1;

鍦ㄤ綘杩炴帴鍒� MySQL 鏁版嵁搴撳悗锛屽彲鑳芥湁澶氫釜鍙互鎿嶄綔鐨勬暟鎹簱锛屾墍浠ヤ綘闇�瑕侀�夋嫨浣犺鎿嶄綔鐨勬暟鎹簱

//閫夋嫨鏁版嵁搴搖ser mydb1

娉ㄦ剰:鎵�鏈夌殑鏁版嵁搴撳悕锛岃〃鍚嶏紝琛ㄥ瓧娈甸兘鏄尯鍒嗗ぇ灏忓啓鐨勩�傛墍浠ヤ綘鍦ㄤ娇鐢⊿QL鍛戒护鏃堕渶瑕佽緭鍏ユ纭殑鍚嶇О銆�

鏌ョ湅鏁版嵁搴撳垱寤虹粏鑺�

show create database mydb1

鍒涘缓涓�涓娇鐢╣bk瀛楃闆嗙殑鏁版嵁搴�

create database mydb2 character set gbk

3.1.4. 琛ㄧ粨鏋勮鍙ユ搷浣�

閫夋嫨鏁版嵁搴�

usemydb1

鍒涘缓MySQL鏁版嵁琛ㄩ渶瑕佷互涓嬩俊鎭細

琛ㄥ悕銆佽〃瀛楁鍚嶃�佸畾涔夋瘡涓〃瀛楁

//鍒涘缓琛╟reate tablestudent(idint,namevarchar(20),sexvarchar(20),ageint,saleryfloat(6,2),birthday date)//鍒犻櫎琛╠rop table student;//鏌ョ湅鎵�鏈夎〃show tables//鏌ョ湅琛ㄧ殑鍒涘缓缁嗚妭show create table student;//灞曠ず琛ㄧ粨鏋刣esc student// 鍦ㄥ師鏈夌殑瀛︾敓鍩虹涓婃坊鍔燼ddress鍒梐lter table student add addressvarchar(20)//鍦ㄥ師鏈夌殑瀛︾敓鍩虹涓婂垹闄ddress鍒梐lter table student drop address

3.1.5. 瀹氫箟琛ㄧ殑绾︽潫

create tablestudent(idintprimary key auto_increment,namevarchar(20)unique not null,sexvarchar(20),ageint,saleryfloat(6,2),birthday date)

濡傛灉浣犱笉鎯冲瓧娈典负 NULL 鍙互璁剧疆瀛楁鐨勫睘鎬т负 NOT NULL锛� 鍦ㄦ搷浣滄暟鎹簱鏃跺鏋滆緭鍏ヨ瀛楁鐨勬暟鎹负NULL 锛屽氨浼氭姤閿欍��

AUTO_INCREMENT瀹氫箟鍒椾负鑷鐨勫睘鎬э紝涓�鑸敤浜庝富閿紝鏁板�间細鑷姩鍔�1銆�

PRIMARY KEY鍏抽敭瀛楃敤浜庡畾涔夊垪涓轰富閿�備负浜嗘爣璇嗘暟鎹簱璁板綍鍞竴鎬э紝涓嶅厑璁歌褰曢噸澶嶏紝涓旈敭鍊间笉鑳戒负绌猴紝涓婚敭涔熸槸涓�涓壒娈婄储寮曘�� 鎮ㄥ彲浠ヤ娇鐢ㄥ鍒楁潵瀹氫箟涓婚敭锛屽垪闂翠互閫楀彿鍒嗛殧銆�

UNIQUE KEY鐨勭敤閫旓細涓昏鏄敤鏉ラ槻姝㈡暟鎹彃鍏ョ殑鏃跺�欓噸澶嶇殑

ENGINE锛氳缃瓨鍌ㄥ紩鎿�

CHARSET锛� 璁剧疆缂栫爜

3.2 DML - 鏁版嵁搴撴搷浣滆瑷�

3.2.1. 姒傚康鍙婁綔鐢�

DML锛歞ata manipulation language 鏁版嵁搴撴搷浣滆瑷�锛岀敤浠ユ搷浣滄暟鎹簱銆�

3.2.2. 鎻掑叆鏁版嵁

//鎻掑叆鏁版嵁insertintostudentvalues(1,鈥檢hangsan鈥�,鈥檔an鈥�,19,389.10,鈥�1999-10-10鈥�);//鏌ヨselect*fromstudent

闂涓�锛氭彃鍏ヤ腑鏂囦細鎶ラ敊

insertintostudentvalues(2,鈥欐潕鍥涒��,鈥欑敺鈥�,19,389.10,鈥�1999-10-10鈥�);

瑙ｅ喅锛�

//閫氱煡鏈嶅姟鍣ㄥ鎴风浣跨敤鐨勭紪鐮佹槸gbksetcharacter_set_client=gbk;//閫氱煡鏈嶅姟鍣ㄥ鎴风鏌ョ湅缁撴灉闆嗕娇鐢ㄧ殑缂栫爜鏄� gbksetcharacter_set_results=gbk;insertintostudent(id,name,sex,age)values(3,鈥欑帇浜斺��,鈥欑敺鈥�,19);

闂浜岋細鏁版嵁搴撳懡浠ゆ濡傛灉鏈変腑鏂囧氨涔辩爜

charset gbk;

3.2.3. 鍒犻櫎鏁版嵁

//鍒犻櫎鍗曟潯鏁版嵁deletefromstudent where id=1;//鍒犻櫎鎵�鏈夋暟鎹紝涓嶅垹闄ょ粨鏋勶紝浼氭斁鍒版棩蹇椾腑锛屼簨鍔℃彁浜ゅ悗鎵嶇敓鏁坉eletefromstudent;//鎽ф瘉琛紝鍒犻櫎琛ㄤ腑鎵�鏈夋暟鎹紝涓嶅垹闄ょ粨鏋勶紝绔嬪嵆鐢熸晥truncate table student;

娉ㄦ剰锛�delete from student;涓巘runcate table student;閮借兘鍒犻櫎璇ヨ〃涓墍鏈夋暟鎹紝鍖哄埆锛氬墠鑰呭垹闄ゅ悗鑷涓婚敭杩樺湪锛屽悗鑰呬富閿細浠�1寮�濮嬨��

3.2.4. 淇敼鏁版嵁

//璁剧疆鎵�鏈変汉鐨勫勾榫勫姞10宀乽pdate studentsetage=age+10//淇敼zhangsan 涓哄紶涓塽pdate studentsetname=鈥欏紶涓夆�檞herename=鈥檢hangsan鈥�//淇敼鐜嬩簲鐨剆alery鍜屽嚭鐢熸棩鏈焨pdate studentsetsalery=100.01,birthday=鈥�1999-10-10鈥檞hereid=3;

3.3 DQL-鏁版嵁搴撴煡璇㈣瑷�

3.3.1.姒傚康鍙婁綔鐢�

Data Query Language 鏁版嵁搴撴煡璇㈣瑷�

3.3.2.鏁版嵁鏌ヨ

//鍒犻櫎studentdrop table student//鍒涘缓鏁版嵁搴撹〃-瀛︾敓鎴愮哗琛╟reate tablestudent(idintprimary key auto_increment,namevarchar(20)unique notnull,chinesefloat,englishfloat,mathfloat);//娣诲姞鍑犳潯鏁版嵁insertintostudentvalues(1,鈥欏紶涓夆��,90,80,80);insertintostudentvalues(2,鈥欐潕鍥涒��,90,87,60);insertintostudentvalues(3,鈥欑帇浜斺��,70,60,69);insertintostudentvalues(4,鈥欒档鍏��,99,90,87);//鏌ヨ鎵�鏈夊鐢熶俊鎭痵elect*fromstudent;//鏌ヨid涓�1鐨勫鐢熶俊鎭痵elect*fromstudentwhereid=1;//鏌ヨid涓�1鐨勫鐢熷鍚峴electnamefromstudentwhereid=1;//鏌ヨ鏁板鎴愮哗澶т簬80鐨勫悓瀛︽垚缁﹕elect*fromstudentwheremath>80//鏌ヨ鎵�鏈夊鐢熸垚缁╋紝骞惰緭鍑烘晥鏋滀负 濮撳悕 璇枃 鑻辫 鏁板 鏁堟灉锛岃涓嬪浘锛歴electnameas濮撳悕,chineseas璇枃,englishas鑻辫,mathas鏁板fromstudent//鏌ヨ鎵�鏈夋垚缁╁強鏁板鍒�+10鍒唖elect*,(math+10)fromstudent//缁熻姣忎釜瀛︾敓鐨勬�诲垎selectname,(math+english+chinese)as鎬诲垎fromstudent//鏌ヨ鎬诲垎澶т簬230鍒嗙殑鍚屽select*fromstudentwhere(math+english+chinese)>230//鏌ヨ鏁板鎴愮哗鍦�80-90涔嬮棿鐨勫悓瀛elect*fromstudentwheremath between80and90//鏌ヨ鏁板璇枃鑻辫閮藉ぇ浜�80鐨勫悓瀛︽垚缁﹕elect*fromstudentwheremath>80and english>80and chinese>80;//鏌ヨ鏁板鎴愮哗鍦� 80 60 90鍐呯殑鍚屽锛屽嵆鏁板鎴愮哗鏈�60銆�80銆�90鐨勩�俿elect*fromstudentwheremathin(80,60,90);//妯＄硦鏌ヨ// _聽 浠ｈ〃涓�涓紝%浠ｈ〃澶氫釜锛�0 - 鏃犻檺锛�//鏌ヨ鎵�鏈夊鍚嶄腑鍖呭惈寮犵殑鍚屽select*fromstudentwherename like 鈥�%寮�%鈥�

鏌ヨ鎵�鏈夊鐢熸垚缁╋紝骞惰緭鍑烘晥鏋�.png

3.3.3. 鎺掑簭鏌ヨ

MySQL涓� 鍗囧簭涓篴sc锛岄檷搴忎负desc

渚嬪锛�

鍗囧簭锛歴elect聽 *聽 from聽 琛ㄥ悕 order by聽 琛ㄤ腑鐨勫瓧娈� asc(MySQL涓粯璁ゆ槸鍗囧簭鎺掑垪锛屽彲涓嶅啓) 锛�

闄嶅簭锛歴elect聽 *聽 from聽 琛ㄥ悕 order by聽 琛ㄤ腑鐨勫瓧娈� desc 锛�

鑻ヨ杩涜鍚屾椂涓�涓崌搴忎竴涓檷搴� 渚嬪锛�

order by 鍗囧簭瀛楁 asc锛岄檷搴忓瓧娈� desc 锛�

//鎸夌収鏁板鎴愮哗浠庡皬鍒板ぇ鏌ヨselect*fromstudent order by math;//鎸夌収鏁板鎴愮哗浠庡ぇ鍒板皬鏌ヨselect*fromstudent order by math desc;

3.3.4.鍒嗛〉鏌ヨ

limit鏄痬ysql鐨勫垎椤垫煡璇㈣娉�:

select * from table limit m,n

鍏朵腑m鏄寚璁板綍浠巑+1寮�濮�,锛孨浠ｈ〃鍙杗鏉¤褰曘��

//鍙栧嚭绗�3鏉¤嚦绗�6鏉★紝4鏉¤褰晄elect*fromstudent limit2,4//鏌ヨ鍑烘暟瀛︽垚缁╃敱楂樺埌浣庡墠涓ゅ悕select*fromstudent order by math desc limit0,2;

3.3.5.鍒嗙粍鏌ヨ

鍒嗙粍鏌ヨ寰楀埌缁撴灉鏄涓�娆℃煡鍒扮殑鏌愪釜缁勫埆銆�

//鍒涘缓涓�涓鍗曡〃create tableemployee(idint,namevarchar(20),sexvarchar(20),ageint);insertintoemployeevalues(1,'sunsan','鐢�',18);insertintoemployeevalues(2,'lisi','鐢�',18);insertintoemployeevalues(3,'wangwu','濂�',19);insertintoemployeevalues(4,'zhaoliu','鐢�',15);//鍒嗙粍鏌ヨselect*fromemployeegroupby sex;//鍒嗙粍鏌ヨ鍔犳潯浠秙elect*fromemployeegroupby sex having age>18;

(1) having 鏉′欢琛ㄨ揪寮忥細鐢ㄦ潵鍒嗙粍鏌ヨ鍚庢寚瀹氫竴浜涙潯浠舵潵杈撳嚭鏌ヨ缁撴灉

(2) having浣滅敤鍜寃here涓�鏍凤紝浣唄aving鍙兘鐢ㄤ簬group by

3.3.6. 鎶ヨ〃鏌ヨ

count聽 涓暟

sum聽 聽 鎬绘暟

avg聽 聽 聽 聽 骞冲潎鏁�

max聽 聽 鏈�澶у��

min聽 聽 鏈�灏忓��

//缁熻鐝骇閲岃竟鏈夊灏戝鐢焥electcount(*)fromstudent;//缁熻鎬绘垚缁╁ぇ浜�250鍒嗙殑浜烘暟selectcount(*)fromstudentwhere(math+english+chinese)>250;//缁熻鐝骇閲岃竟鍚勭鎬绘垚缁﹕electsum(math),sum(english),sum(chinese)fromstudent//缁熻鎵�鏈夌鐩殑鎬绘垚缁﹕electsum(math+english+chinese)fromstudent;//缁熻涓�涓嬭鏂囧钩鍧囨垚缁﹕electsum(chinese)/count(*)fromstudent;selectavg(chinese)fromstudent;//缁熻涓�涓嬬彮绾ц鏂囨渶楂樺垎鍜屾渶浣庡垎selectmax(chinese)fromstudent;selectmin(chinese)fromstudent;//鎶ヨ〃鏌ヨ璁㈠崟鏍规嵁鍚嶇О鍚堝苟鍚庯紝鎬讳环鏍�>10000鐨勫晢鍝乻elect*fromordersgroupby product havingsum(price)>7000

3.4 鏁版嵁鎺у埗璇█

鏁版嵁鎺у埗璇█锛氱畝绉般�怐CL銆�(Data Control Language)锛岀敤鏉ュ畾涔夋暟鎹簱鐨勮闂潈闄愬拰瀹夊叏绾у埆锛屽強鍒涘缓鐢ㄦ埛锛涘叧閿瓧锛歡rant绛�

鍥涖�佸琛ㄨ璁�

4.1.涓�瀵逛竴

涓�寮犺〃鐨勪竴鏉¤褰曚竴瀹氬彧鑳戒笌鍙﹀涓�寮犺〃鐨勪竴鏉¤褰曡繘琛屽搴旓紝鍙嶄箣浜︾劧銆�

鏈夋椂鍊欙紝涓轰簡涓氬姟锛屾垨鑰呴伩鍏嶄竴寮犺〃涓暟鎹噺杩囧ぇ锛岃繃澶嶆潅锛屽湪寮�鍙戜腑浼氳繘琛屼竴瀵逛竴鏂瑰紡鏉ヨ璁¤〃銆�

涓�瀵逛竴.png

4.2. 涓�瀵瑰锛�1鏂瑰缓涓昏〃(id涓轰富閿瓧娈�), 澶氭柟寤哄閿瓧娈碉級

涓�涓疄浣撶殑鏌愪釜鏁版嵁涓庡彟澶栦竴涓疄浣撶殑澶氫釜鏁版嵁鏈夊叧鑱斿叧绯伙紝 涓�瀵瑰鐨勫叧绯诲湪璁捐鐨勬椂鍊欙紝闇�瑕佽璁¤〃鐨勫閿��

4.2.1. 鐝骇琛ㄥ拰瀛︾敓琛ㄨ璁�

image.png

image.png

閮ㄩ棬琛ㄥ拰鍛樺伐琛ㄨ璁�

image.png

4.2.2.鍒涘缓鏁版嵁搴撹〃

constraint 绾︽潫

foreign key灏辨槸琛ㄤ笌琛ㄤ箣闂寸殑鏌愮绾﹀畾鐨勫叧绯伙紝鐢变簬杩欑鍏崇郴鐨勫瓨鍦紝鑳藉璁╄〃涓庤〃涔嬮棿鐨勬暟鎹紝鏇村姞鐨勫畬鏁达紝鍏宠繛鎬ф洿寮恒��

foreign key璇彞鐨勫紡渚嬶細FOREIGN KEY(Sno) REFERENCES Student(Sno)

娉ㄦ剰锛�琛ㄧ殑澶栭敭蹇呴』鏄彟涓�寮犺〃鐨勪富閿�

//鍒涘缓鐝骇琛╟reate tableclass(idintprimary key auto_increment,namevarchar(20));//鍒涘缓瀛︾敓琛╟reate tablestudent(idintprimary key auto_increment,namevarchar(20),sexvarchar(20),class_idint,constraint聽 foreignkey(class_id)referencesclass(id));//鎻掑叆鐝骇鏁版嵁insertintoclassvalues(1,'ceshiban');insertintoclassvalues(2,'kaifa');//鎻掑叆瀛︾敓鏁版嵁insertintostudentvalues(1,'zhangsan','nan',1);insertintostudentvalues(2,'lisi','nan',2);insertintostudentvalues(3,'jingjing','nan',2);//鑱旀煡select*fromstudentwhereclass_id=(selectidfromclasswhereid=2);

琛ヤ竴涓閿殑娉ㄦ剰锛堥粯璁ゆ槸绾︽潫): 鍒犻櫎涓婚敭淇℃伅鏃讹紝褰撹涓婚敭瀛楁鍊煎湪澶栭敭琛ㄤ腑瀛樺湪鏃讹紝璇ヨ褰曟槸涓嶈兘鍒犻櫎鐨勩��---瑕佹妸澶栭敭琛ㄦ槸鐨勭浉鍏充俊鎭垹闄や箣鍚庯紝鎵嶈兘鍒犻櫎銆�

瀛愭煡璇細宓屽鍦ㄥ叾浠栨煡璇腑鐨勬煡璇€��

4.3銆佸瀵瑰锛� 3涓〃= 2涓疄浣撹〃 + 1涓叧绯昏〃 )

涓�涓疄浣撶殑鏁版嵁瀵瑰簲鍙﹀涓�涓疄浣撶殑澶氫釜鏁版嵁锛屽彟澶栧疄浣撶殑鏁版嵁涔熷悓鏍峰搴斿綋鍓嶅疄浣撶殑澶氫釜鏁版嵁銆�

涓�涓鐢熷彲浠ユ湁澶氫釜鑰佸笀锛屼竴涓�佸笀鍙互鏁欏涓鐢�

瑙ｅ喅鏂规锛氬垱寤轰竴涓腑闂磋〃锛屼笓闂ㄧ敤鏉ョ淮鎶ゅ琛ㄤ箣闂寸殑瀵瑰簲鍏崇郴锛岄�氬父鏄兘澶熷敮涓�鏍囪瘑鍑烘暟鎹殑瀛楁锛堜富閿級

create tableteacher(idintprimary key,namevarchar(100));create table student(idintprimary key,namevarchar(100));create tableteacher_student(teacher_idint,student_idint,constraint foreignkey(teacher_id)referencesteacher(id),constraint foreignkey(student_id)referencesstudent(id));insertintoteachervalues(1,'姊佽�佸笀');insertintoteachervalues(2,'鏉庤�佸笀');insertintostudentvalues(1,鈥濆紶涓夆��);insertintostudentvalues(2,鈥濇潕鍥涒��);insertintoteacher_studentvalues(1,1);insertintoteacher_studentvalues(1,2);insertintoteacher_studentvalues(2,1);insertintoteacher_studentvalues(2,2);//鏌ヨ鏉庤�佸笀鎵�鏁欑殑瀛︾敓selectidfromteacherwherename=鈥欐潕鑰佸笀鈥檚electstudent_idfromteacher_studentwhereteacher_id=idselect*fromstudentwhereidin(selectstudent_idfromteacher_studentwhereteacher_id=(selectidfromteacherwherename='鏉庤�佸笀'));//鏌ヨ寮犱笁鐨勬墍鏈夎�佸笀select*fromteacherwhereidin(selectteacher_idfromteacher_studentwherestudent_id=(selectidfromstudentwherename='寮犱笁'));

浜斻�� 杩炶〃鏌ヨ

鍒嗙被锛氬唴杩炴帴銆佸杩炴帴銆佷氦鍙夎繛鎺�

5.1. 鍒濆瀹氫箟琛ㄧ粨鏋�

create tablecustomer(idintprimary key auto_increment,namevarchar(20),cityvarchar(20));create tableorders(idintprimary key auto_increment,good_namevarchar(20),pricefloat(8,2),customer_idint);insertintocustomer(name,city)values('鏉庤�佸笀','涓滃寳');insertintocustomer(name,city)values('宕旇�佸笀','灞辫タ');insertintocustomer(name,city)values('寮犺�佸笀','鍐呰挋');insertintocustomer(name,city)values('闂�佸笀','澶╂触');insertintoorders(good_name,price,customer_id)values('鐢佃剳',59,1);insertintoorders(good_name,price,customer_id)values('绗旇鏈�',88,2);insertintoorders(good_name,price,customer_id)values('鍚归鏈�',99,1);insertintoorders(good_name,price,customer_id)values('棣欐按',300,3);insertintoorders(good_name,price,customer_id)values('鐗涘ザ',100,6);

5.2.浜ゅ弶鏌ヨ

浜ゅ弶鏌ヨ锛屽張鍙瑳鍗″皵绉煡璇紝浼氬皢宸﹁〃鍜屽彸琛ㄧ殑淇℃伅锛屽仛涓�涓箻绉皢鎵�鏈変俊鎭煡璇㈠嚭鏉ワ紝浼氫骇鐢熶复鏃惰〃锛屾瘮杈冨崰鐢ㄥ唴瀛橈紝鐢熸垚鐨勮褰曟暟=琛�1 X琛�2

select*fromcustomer,orders;select*fromcustomer crossjoinorders;

5.3. 鍐呰繛鎺ユ煡璇�

鍐呰繛鎺ワ紝inner join on 鏌ヨ涓ゅ紶琛紝璁惧畾鏉′欢锛屽皢涓ゅ紶琛ㄤ腑瀵瑰簲鐨勬暟鎹煡璇㈠嚭鏉�

涓嶄細浜х敓绗涘崱灏旂Н锛屼笉浼氫骇鐢熶复鏃惰〃锛屾�ц兘楂�

select*fromcustomer c innerjoinorders o on c.id=o.customer_id;select*fromcustomer,orderswherecustomer.id=orders.customer_id;select*fromcustomer c,orders owherec.id=o.customer_id;

5.4. 宸﹀杩炴帴

宸﹀杩炴帴聽 left join on 璁惧畾鏉′欢锛屽皢涓ゅ紶琛ㄥ搴旂殑鏁版嵁鏌ヨ鍑烘潵锛屽悓鏃�灏嗗乏琛ㄨ嚜宸辨病鏈夊叧鑱旂殑鏁版嵁涔熸煡璇㈠嚭鏉�

娉ㄦ剰锛歫oin鍓嶉潰鏄乏锛屽悗闈㈡槸鍙�

select*fromcustomer c leftjoinorders o on c.id=o.customer_id;

5.5. 鍙冲杩炴帴

鍙冲杩炴帴 right join聽 on 璁惧畾鏉′欢锛屽皢涓ゅ紶琛ㄥ搴旂殑鏁版嵁鏌ヨ鍑烘潵锛屽悓鏃�灏嗗彸琛ㄨ嚜宸辨病鏈夊叧鑱旂殑鎵�鏈夋暟鎹煡璇㈠嚭鏉�

select*fromcustomer c rightjoinorders o on c.id=o.customer_id;

5.6. 鑱斿悎鏌ヨ

select*fromcustomer leftjoinorders on customer.id=orders.customer_idhaving price>20;

鍏�丮ySQL鍥惧舰鍖栧伐鍏穘avicat

6.1. 瀹夎浠嬬粛

MySQL甯歌鐨勫浘褰㈠寲宸ュ叿

6.2. Navicat宸ュ叿浣跨敤姝ラ

6.2.1. 閾炬帴锛宮ysql锛岃緭鍏ョ敤鎴峰悕锛屽瘑鐮�

杩炴帴.png

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6.2.2.鏂板缓搴擄紝榧犳爣鐐瑰嚮鍙抽敭

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6.2.3.鏂板缓琛�

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涓冦�佹暟鎹簱澶囦唤涓庢仮澶�

1. 浣跨敤鍥惧舰鐣岄潰宸ュ叿锛�

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2. 浣跨敤doc鍛戒护锛�

mysqldump 鈥搖鐢ㄦ埛鍚� 鈥損瀵嗙爜 鏁版嵁搴撳悕>鐢熸垚鐨勮剼鏈枃浠惰矾寰�

娉ㄦ剰锛屼笉瑕佹墦鍒嗗彿锛屼笉瑕佺櫥褰昺ysql锛岀洿鎺ュ湪cmd涓嬭繍琛�

娉ㄦ剰锛岀敓鎴愮殑鑴氭湰鏂囦欢涓笉鍖呭惈create database璇彞

mysqldump -uroot -proot host>C:\Users\Administrator\Deskt

op\mysql\1.sql

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3. 瀵煎叆SQL鏂囦欢

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瀵煎叆鏂囦欢

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鍒锋柊鍗冲彲锛孎5鍒锋柊

4.鎭㈠

a)浣跨敤鍥惧舰鐣岄潰宸ュ叿锛�

b)浣跨敤doc鍛戒护琛岋細

i.涓嶇櫥褰曟仮澶�

mysql -u鐢ㄦ埛鍚� -p瀵嗙爜 鏁版嵁搴�<鑴氭湰鏂囦欢璺緞

娉ㄦ剰锛屼笉瑕佹墦鍒嗗彿锛屼笉瑕佺櫥褰昺ysql锛岀洿鎺ュ湪cmd涓嬭繍琛�

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ii.鐧诲綍涔嬪悗鎭㈠

閫夋嫨搴� use 搴撳悕绉�

Source sql鏂囦欢璺緞

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鍏�佹暟鎹簱甯哥敤鎬ц兘浼樺寲锛堜簡瑙ｏ級

鏁版嵁搴撴�ц兘浼樺寲杩欏潡锛屾垜浠�冭檻姣旇緝澶氱殑杩樻槸鏌ヨ杩欏潡锛屼簰鑱旂綉椤圭洰瀵规暟鎹煡璇㈤潪甯搁绻侊紝瀵规晥鐜囷紝鎬ц兘瑕佹眰姣旇緝楂樸��

鏌ヨ杩欏潡浼樺寲鐨勮瘽锛屼富瑕佸氨闇�瑕佷娇鐢ㄧ储寮曡繖绉嶆柟寮忥紝鎵�璋撶储寮曞氨鏄缓绔嬩竴绉嶅揩閫熸煡鎵剧殑鏂瑰紡锛屾瘮濡傛垜浠煡瀛楀吀,鏈変竴涓狝BCD鐨勭储寮�.

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涓句釜渚嬪瓙,濡傛灉鎴戜滑鍒涘缓涓�涓〃create table user(id integer ,name varchar(20)锛宩ob varchar(20));濡傛灉鎴戜滑鏁版嵁搴撲腑鏈�1000涓囨潯鏁版嵁锛屽綋鎴戞煡璇elect * from user where name=鈥欏紶涓夆�欑殑鏃跺��,杩欑鏌ヨ鏂瑰紡灏辩被浼间簬鏁翠釜鏁版嵁搴撶殑鎵弿锛屾晥鐜囬潪甯镐綆銆�

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鎴戜滑鍙互缁欒繖涓猲ame璁剧疆涓�涓储寮昪reate index n on user (name);杩欐槸璁剧疆涓�绉嶆櫘閫氾紙normal锛夌储寮曪紝鐒跺悗鎴戜滑鏌ヨ鐨勬椂鍊欙紝鏈変簡杩欎釜绱㈠紩锛屾晥鐜囧氨浼氬ぇ澶ф彁鍗囷紝褰撶劧瀵逛簬绱㈠紩锛屽畠鐨勬柟寮忔湁BTree绫诲瀷鍜孒ash绫诲瀷锛屾槸涓ょ绠＄悊鏁版嵁搴撶储寮曠殑鏂瑰紡锛岃繖涓垜娌℃湁娣卞叆鐮旂┒銆傝繖涓垜浠彲浠ヨ嚜宸辫缃�傞粯璁ゆ槸btree銆�

绱㈠紩绫诲瀷鐨勮瘽锛屾湁normal锛堟櫘閫氱被鍨嬶級绫诲瀷銆乽nique锛堝敮涓�绫诲瀷锛夈�乫ulltext鍏ㄦ枃绱㈠紩銆佷富閿储寮曘�侀潪绌虹储寮曘�佽仛闆嗙储寮曘��

鈶犱富閿储寮曪紝primary key 鍦ㄨ缃殑鏃跺�欙紝宸茬粡鎸囧畾浜嗭紝鍏跺疄涔熸槸闈炵┖绱㈠紩銆�

鈶￠潪绌虹储寮曟槸not null,璁剧疆杩欑鏂瑰紡鐨勮瀛楁涓嬪唴瀹逛笉鑳戒负绌猴紝

鈶㈣仛闆嗙储寮�(鑱斿悎绱㈠紩)锛屾槸鍦ㄨ缃涓煡璇㈡潯浠剁殑鏃跺�欎娇鐢ㄣ�傛瘮濡� 鍒涘缓涓�寮犺〃锛屾湁鍚嶅瓧锛屾湁宸ヤ綔锛屾垜浠兂缁忓父棰戠箒鐨勭敤鍒板悕瀛楀拰宸ヤ綔瀹冧咯缁撳悎鍦ㄤ竴璧锋潵鏌ヨ鏁版嵁搴撲腑琛ㄧ殑鏁版嵁銆傝繖涓椂鍊欙紝鍙互灏嗗悕瀛楀拰宸ヤ綔鎸囧畾涓鸿仛闆嗙储寮曘�俢reate index m on user(name,job); 杩欐牱褰撴垜浠寚瀹歴elect * from user where name=xxx and job=xxx鐨勬椂鍊欙紝灏变細鎸夌収绱㈠紩鏂瑰紡鏉ュ仛銆�

杩欑浼樺寲鏂瑰紡灏辨槸绱㈠紩浼樺寲锛屽湪浣跨敤绱㈠紩浼樺寲鏂规鐨勬椂鍊欙紝鎴戜滑闇�瑕佹敞鎰忛伩鍏嶅湪绱㈠紩瀛楁涓婁娇鐢ㄦ潯浠跺嚱鏁扮瓑鎿嶄綔銆�

浜嗚В锛�

Show index form orders;鏌ョ湅绱㈠紩

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涔濄�佹暟鎹簱鎬ц兘妫�娴嬫柟寮忥紙浜嗚В锛�

鍦ㄨ璁QL鐨勬椂鍊欙紝鎴戜滑涓�鑸細浣跨敤explain妫�娴媠ql锛岀湅鏄惁浣跨敤鍒扮储寮曪紝閬垮厤鍑虹幇鏁磋〃鎼滅储鏂瑰紡鏌ヨ[filesort(涓嶆槸浠ョ储寮曟柟寮忕殑妫�绱紝鎴戜滑鍙仛filesort)]锛堟垜鍦ㄨ繖寮犺〃涓妸gender璁剧疆鎴恘ormal绱㈠紩锛宯ame娌℃湁浠讳綍璁剧疆锛�

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瀵规瘮鐪嬬殑锛屽鏈夌储寮曠殑瀛楁,鍦ㄦ娴嬬殑鏃跺�欙紝浼氭樉绀烘槸涓�涓紩鐢ㄧ殑key銆�

explain select*from tb_product where title='';

杩樺彲浠ヤ娇鐢╬rofiling鏂瑰紡妫�娴嬫暟鎹簱鎵ц鐨勬柟寮忥紝鍙互鏌ヨsql鐨勮繍琛屾椂闂淬��http://www.jb51.net/article/31870.htm

娉ㄩ噴锛氭煡鐪媝rofiling淇℃伅锛宻how variables like '%profiling%';

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绗竴姝ワ細set profiling=1;锛堝紑鍚痯rofiling锛�

绗簩姝ヨ繍琛岋細select title from tb_product ;

绗笁姝ワ細鏌ョ湅杩愯鏃堕棿show profiles;

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Duration锛氭寔缁椂闂达紝浜嬩欢鑺辫垂鐨勬椂闂存�昏锛堜互姣涓哄崟浣嶏紵锛�