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聽 聽 聽 聽 2.澶у皬鍐欎笉鏁忔劅
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瀹樼綉涓嬭浇 mysql 鍜孨avicat for mysql
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鍦╞in鐩綍閲屽惎鍔╠os绐楀彛
mysql -uroot -p瀵嗙爜
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use 鏁版嵁搴撳悕
涓夈�丮ysql鏁版嵁绫诲瀷
1銆佹暣鍨�
MySQL鏁版嵁绫诲瀷鍚箟锛堟湁绗﹀彿锛�
tinyint(m)1涓瓧鑺偮� 鑼冨洿(-128~127)
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2銆佹诞鐐瑰瀷(float鍜宒ouble)
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3銆佸畾鐐规暟
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decimal(m,d)聽
4銆佸瓧绗︿覆
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desc 琛ㄥ悕 瑙傚療琛ㄧ粨鏋�
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鎿嶄綔鏁版嵁搴�(浜嗚В)
1.鍒涘缓
Create database mydb1;
Create database mydb2 character set gbk;
2.鏌ヨ
鏌ョ湅褰撳墠鏁版嵁搴撴湇鍔″櫒涓殑鎵�鏈夋暟鎹簱
Show databases;
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Show create database mydb2;
3..淇敼
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alter database mydb2 character set utf8;
4.鍒犻櫎
Drop database mydb3;
5.鍏朵粬
鏌ョ湅褰撳墠浣跨敤鐨勬暟鎹簱
Select database();
6.鍒囨崲鏁版嵁搴�
Use mydb2;
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DDL鏁版嵁瀹氫箟璇█
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create
璇硶锛�
create table <琛ㄥ悕>(
<鍒楀悕> 鏁版嵁绫诲瀷 [鍒楃骇瀹屾暣鎬х害鏉熸潯浠禲,
<鍒楀悕> 鏁版嵁绫诲瀷 [鍒楃骇瀹屾暣鎬х害鏉熸潯浠禲,
...
[琛ㄧ骇瀹屾暣鎬х害鏉熸潯浠�(鍙悓鏃剁害鏉熷鍒�)]
);
鏁版嵁瀹屾暣鎬�
浣滅敤锛氫繚璇佺敤鎴疯緭鍏ョ殑鏁版嵁淇濆瓨鍒版暟鎹簱涓槸姝ｇ‘鐨勩��
瀹屾暣鎬х殑鍒嗙被锛�
1.瀹炰綋瀹屾暣鎬�:
2.鍩熷畬鏁存��:
3.寮曠敤瀹屾暣鎬�:
鍒楃骇绾︽潫鏉′欢
1.瀹炰綋瀹屾暣鎬�
瀹炰綋锛氬嵆琛ㄤ腑鐨勪竴琛�(涓�鏉¤褰�)浠ｈ〃涓�涓疄浣擄紙entity锛�
瀹炰綋瀹屾暣鎬х殑浣滅敤锛氭爣璇嗘瘡涓�琛屾暟鎹笉閲嶅銆�
绾︽潫绫诲瀷锛�涓婚敭绾︽潫锛坧rimary key锛�鍞竴绾︽潫(unique)鑷姩澧為暱鍒�(auto_increment)
(1)涓婚敭绾︽潫锛坧rimary key锛�
娉細姣忎釜琛ㄤ腑瑕佹湁涓�涓富閿�,涓斿彧鑳芥湁涓�涓�
鐗圭偣锛氭暟鎹敮涓�锛屼笖涓嶈兘涓簄ull,鎻掑叆鏁版嵁鐨勭粍鍚堜腑浠讳綍涓�涓暟鎹兘涓嶈兘鏄痭ull
锛�2锛夊敮涓�绾︽潫(unique)锛氱壒鐐癸細鏁版嵁涓嶈兘閲嶅銆傚彲null
锛�3锛夎嚜鍔ㄥ闀垮垪(auto_increment)锛屼竴涓〃鍙兘鏈変竴涓嚜澧炲垪锛堝彧鑳芥坊鍔犲埌涓婚敭绾︽潫鎴栧敮涓�绾︽潫涓婏級
2.鍩熷畬鏁存��
鍩熷畬鏁存�х殑浣滅敤锛氬煙浠ｈ〃褰撳墠鍗曞厓鏍硷紝闄愬埗姝ゅ崟鍏冩牸鐨勬暟鎹纭紝
鍩熷畬鏁存�х害鏉燂細鏁版嵁绫诲瀷闈炵┖绾︽潫锛坣ot聽null锛夐粯璁ゅ�肩害鏉�(default)聽check绾︽潫锛坢ysql涓嶆敮鎸侊級check(sex='鐢�'orsex='濂�')
锛�1锛塶ot null 涓嶄负绌� 聽null鍙负绌�
锛�2锛塪efault 榛樿鍊� 聽 聽 聽 聽缁欏彉閲忚祴榛樿鍊�
3.寮曠敤瀹屾暣鎬�锛堝弬鐓у畬鏁存�э級
澶栭敭绾︽潫
鍒楃骇绾︽潫鐩存帴澹版槑鍚庢坊鍔狅細deptno int REFERENCES dept(deptno)
琚害鏉熺殑鍒楀繀椤绘槸鍙︿竴涓〃涓殑鍏锋湁鍞竴鎬х殑涓�鍒�
娉細1.寰�鍏锋湁澶栭敭绾︽潫鐨勫瓧娈典腑娣诲姞鏁版嵁锛岃繖涓暟鎹繀椤绘槸鍙︿竴寮犺〃涓寚瀹氬瓧娈典腑鍑虹幇鐨勬暟鎹�
2.琚害鏉熺殑瀛楁鍜岀害鏉熺殑瀛楁涓嶄竴瀹氳鍚嶅瓧鐩稿悓
3.鍒犻櫎琛ㄧ殑鏃跺�欏厛鍒犻櫎娣诲姞澶栭敭绾︽潫鐨勮〃锛屽啀鍒犻櫎鍙傜収鐨勮〃
瀹為檯寮�鍙戜腑寰堝皯浣跨敤澶栭敭绾︽潫锛岃�屾洿澶氫娇鐢ㄧ殑鏄笟鍔￠�昏緫杩涜鍒ゆ柇
琛ㄧ骇绾︽潫鏉′欢锛�
锛�1锛塩onstraint <绾︽潫鍚�> unique(鍒�1锛屽垪2) 琛ㄧず缁勫悎鍞竴
锛�2锛塸rimary key(classid锛宻tuid) 聽鑱斿悎涓婚敭锛屼袱涓�煎喅瀹氫富閿�硷紝
锛�3锛塁ONSTRAINT 聽 澶栭敭绾︽潫鍚� 聽foreign key (sid) references student(sid涓婚敭));
鏈〃鐨剆id渚濊禆student琛ㄤ腑鐨勪富閿畇id
Drop
Drop Table <琛ㄥ悕> 聽鏈夊叧鑱旇〃鍏堣В闄ゅ叧鑱斿啀鍒犺〃
Alter锛堟槸閽堝琛ㄧ粨鏋勭殑鏇存敼锛�
娉細alter閽堝琛ㄧ粨鏋勭殑鏇存敼锛屽彲浠ラ�氳繃鍥惧舰鍖栧伐鍏风洿鎺ユ搷浣滐紝浣滀负浜嗚В
1.娣诲姞鍒� 聽
Alter Table <琛ㄥ悕> ADD <鏂板垪鍚�><鏁版嵁绫诲瀷>[瀹屾暣鎬х害鏉熸潯浠禲 聽
(after 瀛楁鍚�(鎸囧畾瀛楁鍚庢坊鍔�)/first(绗竴鍒楁坊鍔�))
2.鍒犻櫎鍒�
ALTER TABLE <琛ㄥ悕> DROP <鍒楀悕>
3.淇敼鍒楁暟鎹被鍨�
ALTER TABLE <琛ㄥ悕> MODIFY <鍒楀悕> <鏁版嵁绫诲瀷>[绾︽潫鏉′欢]
4.淇敼琛ㄥ悕
ALTER TABLE <鏃ц〃鍚�> RENAME TO <鏂拌〃鍚�>
5.淇敼瀛楁鍚�
ALTER TABLE <琛ㄥ悕> 聽 聽CHANGE <鏃у垪鍚�> <鏂板垪鍚�> <鏂版暟鎹被鍨�>
6.澧炶ˉ绾︽潫
锛�1锛変富閿� 聽ALTER TABLE <琛ㄥ悕> ADD CONSTRAINT <绾︽潫鍚�> 锛堢害鏉熺被_琛ㄥ悕_鍒楀悕锛塒RIMARY KEY[UNIQUE] <(鍒楀悕)>
锛�2锛夊閿� ALTER TABLE <琛ㄥ悕> ADD CONSTRAINT <绾︽潫鍚�> FOREIGN KEY <(鍒楀悕)> REFERENCES <琛ㄥ悕><(鍒楀悕)>
锛�3锛夐粯璁ゅ�� ALTER TABLE <琛ㄥ悕> ALTER <鍒楀悕> SET DEFAULT 榛樿鍊�
锛�4锛夎嚜澧炲垪 聽ALTER 聽TABLE <琛ㄥ悕> MODIFY 聽COLUMN<鍒楀悕> 聽<鏁版嵁绫诲瀷> 聽NOT NULL聽 <绾︽潫锛堜富閿垨鑰呭敮涓�鎬х害鏉燂級> 聽 聽 AUTO_INCREMENT
7.鍒犻櫎绾︽潫
1.涓婚敭 ALTER TABLE<琛ㄥ悕> DROP PRIMARY KEY
2.鍞竴鍊� ALTER TABLE <琛ㄥ悕> DROP INDEX <鍒楀悕>
3. 澶栭敭 ALTER TABLE <琛ㄥ悕> DROP FOREIGN KEY 绾︽潫鍚�
4.鍒犻櫎鑷闀� 聽ALTER TABLE <琛ㄥ悕> MODIFY <鍒楀悕> <鏁版嵁绫诲瀷>
DML鏁版嵁鎿嶄綔璇█
DML鏄琛ㄤ腑鐨勬暟鎹繘琛屽銆佸垹銆佹敼鐨勬搷浣溿�備笉瑕佷笌DDL娣锋穯浜嗐��
INSERT聽
1.鎻掑叆涓嶅瓨鍦ㄧ殑鏁版嵁 聽INSERT INTO <琛ㄥ悕> [(鍒�1锛屽垪2锛屽垪3...)] values 锛�' 鍊�1','鍊�2 ','鍊�3 '锛�,锛�' 鍊�1','鍊�2 ','鍊�3 '锛�..
娉細鎻掑叏閮ㄦ暟鎹殑鏃跺�欏彲浠ヤ笉鍐欏垪鍚�
2.灏嗘煡璇㈢殑鏁版嵁鏌ュ埌鏁版嵁琛�
INSERT INTO <琛ㄥ悕> [(鍒�1锛屽垪2....)] 聽SELECT 鏌ヨ璇彞
UPDATE锛堥拡瀵瑰�肩殑鏇存敼锛�
UPDATE <琛ㄥ悕> SET 鍒楀悕1=鍊艰〃杈惧紡[,鍒楀悕2=鍊艰〃杈惧紡].....[WHERE 鏉′欢琛ㄨ揪寮廬
DELETE
DELETE FROM <琛ㄥ悕> [WHERE 琛ㄨ揪寮廬
渚嬶細鍒犻櫎id灏忎簬10鐨勬暟鎹褰�
DELETE 鍒犻櫎鐨勬暟鎹� FROM student WHERE ID<10
TRUNCATE鍒犻櫎鏄妸琛ㄧ洿鎺ROP鎺夛紝鐒跺悗鍐嶅垱寤轰竴涓悓鏍风殑鏂拌〃銆傚垹闄ょ殑鏁版嵁涓嶈兘鎵惧洖銆傛墽琛岄�熷害姣擠ELETE蹇��
Truncate Table<琛ㄥ悕> 娓呯┖琛ㄦ暟鎹�
DQL鏁版嵁鏌ヨ璇█
鏌ヨ杩斿洖鐨勭粨鏋滈泦鏄竴寮犺櫄鎷熻〃銆�
SELECT
瀹為檯搴旂敤鏃讹紝鏌ヨ鏄笉鍙敤select * 骞朵笖涓�瀹氳鍐欐潯浠讹紝鍥犱负鍏徃鏁版嵁寰堝锛屼笉鍐欐潯浠朵細寮曡捣姝绘満
SELECT [ALL|DISTINCT] <鍒楀悕>,[<鍒楀悕>...]
FROM <琛ㄥ悕鎴栬鍥惧悕> [琛ㄥ悕鎴栬鍥惧悕]
[WHERE <鏉′欢琛ㄨ揪寮�>]
[GROUP BY <鍒楀悕> [HAVING] <鏉′欢琛ㄨ揪寮�>]]
[ORDER BY <鍒楀悕>[ASC|DESC]] 聽 聽[LIMIT m,n];
*---->浠ｈ〃鎵�鏈�
DISTINCT锛氭秷闄ゆ煡璇㈠埌鐨勯噸澶嶇粨鏋滐紙鑻ュ悗闈㈣窡鐫�澶氫釜鍒楋紝鍘婚櫎鐨勬槸閲嶅缁勫悎锛�
LIMIT m,n 聽 聽m琛ㄧず寮�濮嬩綅缃紝n琛ㄧず闀垮害锛堣幏鍙栨煡璇㈢粨鏋滅殑涓�閮ㄥ垎鍐呭锛夛紝娉細绗竴琛屾暟鎹负0
鎵ц椤哄簭锛�FROM 聽聽WHERE 聽聽GROUP BY 聽聽HAVING 聽SELECT 聽DISTINCT 聽聽ORDER BY 聽LIMIT
鏉′欢鏌ヨWHERE聽
=銆�<=>瀹夊叏绛夊彲鍒ゆ柇涓よ�呮槸鍚﹂兘涓簄ull锛�!=銆�<>涓嶇瓑銆�<銆�<=銆�>銆�>=锛�
AND 骞朵笖聽聽OR鎴� 聽聽聽NOT 聽闈灺�
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<鍒楀悕> in 锛堬級鍦ㄦ嫭鍙烽噷鐨勫�煎彇锛宯ot in
IS NULL 聽 琛ㄧず涓虹┖ 聽 IS NOT NULL 涓嶄负绌�
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_ 涓嬪垝绾胯〃绀轰竴涓瓧绗� 聽渚嬶細 LIKE '瀛檁'
%琛ㄧず浠绘剰闀垮害 聽 聽 聽 聽 聽渚嬶細 LIKE '瀛�%' 聽 聽 LIKE '%M%'鍑虹幇杩嘙
[m,n]m鍒皀涓暱搴�
鑱氬悎鍑芥暟
sum() 聽 avg() 聽 min() 聽 max() count()
鑱氬悎鍑芥暟鍙互宓屽 聽 max(avg(sal)) 聽鏌ヨ骞冲潎鍊兼渶澶х殑涓�缁�
娉細鑱氬悎鍑芥暟缁熻鐨勬槸闈濶ULL鐨勬暟鎹紝
濡傛灉涓�涓垪鏈夊緢澶氳褰曠殑鍊间负NULL锛屽洜涓轰换浣曚笢瑗夸笌NULL鐩稿姞缁撴灉杩樻槸NULL锛屾墍浠ョ粨绠楃粨鏋滃彲鑳戒細鍑虹幇NULL銆備笅闈娇鐢ㄤ簡鎶奛ULL杞崲鎴愭暟鍊�0鐨勫嚱鏁癐FNULL锛�
SELECT *,sal+IFNULL(鍒楀悕,0) FROM emp;
鍒嗙粍
GROUD BY (鏍规嵁鏌愪釜鏉′欢瀵规暟鎹繘琛屽垎缁�) 聽铏借鏄垎缁勪絾鏄垎缁勫悗鐨勬暟鎹槸鏃犳硶鐩存帴鍏ㄩ儴鎵撳嵃鍑烘潵鐨勶紝寮鸿鎵撳嵃姣忕粍鍙細鏄剧ず姣忕粍鐨勪竴涓暟鎹�傦紙鍙互浣跨敤GROUP_CONCAT(瀛楁)鍑芥暟鏉ユ樉绀哄垎缁勬暟鎹級
GROUD BY鍙互瀵逛袱涓睘鎬ц繘琛屽垎缁勶紝杩欐椂鍒嗙殑缁勬槸浠ヤ袱涓睘鎬х殑缁勫悎杩涜鍒嗙殑缁勶紝缁勫拰鐩稿悓涓轰竴缁勩��
鍒嗙粍鍙互鐞嗚В鎴愪负锛屾妸浣爂roup聽by鍚庨潰鐨勫瓧娈典綔涓轰竴涓暣浣擄紝杈撳嚭涓�鏉′綘鎯冲緱鍒扮殑涓�绉嶈仛鍚堝嚱鏁扮被鍨嬬殑鏁版嵁锛屾墍浠�鍒嗙粍鍜岃仛鍚堝嚱鏁�鎭伅鐩稿叧銆�
鍒嗙粍鍑芥暟鐨勬槸姣忎竴缁勫琛岃緭鍏ワ紝鍗曡杈撳嚭 杩欓噷灏辫В閲婁簡 聽select ename max锛坰al锛� from emp 聽锛屽洜涓篹name鍙兘鏄涓紝灏变骇鐢熶簡澶氳杈撳嚭锛屼骇鐢熶簡鏃犳硶鍖归厤鐨勯棶棰�
娉細鍑虹幇鍦ㄦ煡璇㈣鍙ラ噷鐨勫瓧娈碉紝濡傛灉娌″嚭鐜板湪鑱氬悎鍑芥暟涓紝灏变竴瀹氳鍑虹幇鍦╣roud by涓笉鐒朵細鍑虹幇涓婅堪闂
SELECT s_id,count(*) AS total
from fruits
group by s_id with rollup 聽 聽
娉細with rollup琛ㄧず鐨勬槸鎵�鏈塩ount(*)鐨勫拰锛屼篃灏辨槸鎵�璇寸殑鎬昏锛�
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having涓巜here鐨勫尯鍒�:
1.having鏄湪鍒嗙粍鍚庡鏁版嵁杩涜杩囨护.
where鏄湪鍒嗙粍鍓嶅鏁版嵁杩涜杩囨护
2.having鍚庨潰鍙互浣跨敤鍒嗙粍鍑芥暟(缁熻鍑芥暟)
where鍚庨潰涓嶅彲浠ヤ娇鐢ㄥ垎缁勫嚱鏁般��
WHERE鏄鍒嗙粍鍓嶈褰曠殑鏉′欢锛屽鏋滄煇琛岃褰曟病鏈夋弧瓒砏HERE瀛愬彞鐨勬潯浠讹紝閭ｄ箞杩欒璁板綍涓嶄細鍙傚姞鍒嗙粍锛涜�孒AVING鏄鍒嗙粍鍚庢暟鎹殑绾︽潫銆�
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ORDER BY <鍒�1>[ASC|DESC],[<鍒�1>[ASC|DESC]] 聽 鍏堟帓鍒�1锛屽垪1鐩稿悓鍐嶆帓鍒�2
DESC鍊掑簭锛孉SC姝ｅ簭(榛樿)
琛ㄤ笌琛ㄤ箣闂寸殑鍏崇郴
涓�瀵逛竴锛氫緥濡倀_person琛ㄥ拰t_card琛紝鍗充汉鍜岃韩浠借瘉銆傝繖绉嶆儏鍐甸渶瑕佹壘鍑轰富浠庡叧绯伙紝鍗宠皝鏄富琛紝璋佹槸浠庤〃銆備汉鍙互娌℃湁韬唤璇侊紝浣嗚韩浠借瘉蹇呴』瑕佹湁浜烘墠琛岋紝鎵�浠ヤ汉鏄富琛紝鑰岃韩浠借瘉鏄粠琛ㄣ�傝璁′粠琛ㄥ彲浠ユ湁涓ょ鏂规锛�
鍦╰_card琛ㄤ腑娣诲姞澶栭敭鍒楋紙鐩稿t_user琛級锛屽苟涓旂粰澶栭敭娣诲姞鍞竴绾︽潫锛�
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涓�瀵瑰锛堝瀵逛竴锛夛細鏈�涓哄父瑙佺殑灏辨槸涓�瀵瑰锛佷竴瀵瑰鍜屽瀵逛竴锛岃繖鏄粠鍝釜瑙掑害鍘荤湅寰楀嚭鏉ョ殑銆倀_user鍜宼_section鐨勫叧绯伙紝浠巘_user鏉ョ湅灏辨槸涓�瀵瑰锛岃�屼粠t_section鐨勮搴︽潵鐪嬪氨鏄瀵逛竴锛佽繖绉嶆儏鍐甸兘鏄湪澶氭柟鍒涘缓澶栭敭锛�
澶氬澶�锛氫緥濡倀_stu鍜宼_teacher琛紝鍗充竴涓鐢熷彲浠ユ湁澶氫釜鑰佸笀锛岃�屼竴涓�佸笀涔熷彲浠ユ湁澶氫釜瀛︾敓銆傝繖绉嶆儏鍐甸�氬父闇�瑕佸垱寤轰腑闂磋〃鏉ュ鐞嗗瀵瑰鍏崇郴銆備緥濡傚啀鍒涘缓涓�寮犺〃t_stu_tea琛紝缁欏嚭涓や釜澶栭敭锛屼竴涓浉瀵箃_stu琛ㄧ殑澶栭敭锛屽彟涓�涓浉瀵箃_teacher琛ㄧ殑澶栭敭銆�
澶氳〃鏌ヨ锛堥噸鐐癸級
澶氳〃鏌ヨ鏈夊涓嬪嚑绉嶏細
1.鍚堝苟缁撴灉闆嗭紱UNION銆乁NION ALL
2.杩炴帴鏌ヨ
鍐呰繛鎺INNER] JOIN ON
澶栬繛鎺UTER JOIN ON
宸﹀杩炴帴LEFT [OUTER] JOIN
鍙冲杩炴帴RIGHT [OUTER] JOIN
鑷劧杩炴帴NATURAL JOIN
3.瀛愭煡璇�
鍚堝苟缁撴灉闆�
1.鍚堝苟缁撴灉闆�
浣滅敤锛氬悎骞剁粨鏋滈泦灏辨槸鎶婁袱涓猻elect璇彞鐨勬煡璇㈢粨鏋滃悎骞跺埌涓�璧凤紒
鍚堝苟缁撴灉闆嗘湁涓ょ鏂瑰紡锛�
UNION锛氬幓闄ら噸澶嶈褰曪紝渚嬪锛歋ELECT* FROM t1 UNION SELECT * FROM t2锛�
UNION ALL锛氫笉鍘婚櫎閲嶅璁板綍锛屼緥濡傦細SELECT * FROM t1 UNION ALL SELECT * FROM t2銆�
瑕佹眰锛�琚悎骞剁殑涓や釜缁撴灉锛氬垪鏁般�佸垪绫诲瀷蹇呴』鐩稿悓銆�
2.杩炴帴鏌ヨ锛堥噸鐐癸級
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聽 聽 聽 聽 杩炴帴鏌ヨ浼氫骇鐢熺瑳鍗″皵绉紝鍋囪闆嗗悎A={a,b}锛岄泦鍚圔={0,1,2}锛屽垯涓や釜闆嗗悎鐨勭瑳鍗″皵绉负{(a,0),(a,1),(a,2),(b,0),(b,1),(b,2)}銆傚彲浠ユ墿灞曞埌澶氫釜闆嗗悎鐨勬儏鍐点��
聽 聽 聽 聽 閭ｄ箞澶氳〃鏌ヨ浜х敓杩欐牱鐨勭粨鏋滃苟涓嶆槸鎴戜滑鎯宠鐨勶紝閭ｄ箞鎬庝箞鍘婚櫎閲嶅鐨勶紝涓嶆兂瑕佺殑璁板綍鍛紝褰撶劧鏄�氳繃鏉′欢杩囨护銆傞�氬父瑕佹煡璇㈢殑澶氫釜琛ㄤ箣闂撮兘瀛樺湪鍏宠仈鍏崇郴锛岄偅涔堝氨閫氳繃鍏宠仈鍏崇郴鍘婚櫎绗涘崱灏旂Н銆�
聽 聽 聽 聽 聽浣犺兘鎯冲儚鍒癳mp鍜宒ept琛ㄨ繛鎺ユ煡璇㈢殑缁撴灉涔堬紵emp涓�鍏�14琛岃褰曪紝dept琛ㄤ竴鍏�4琛岃褰曪紝閭ｄ箞杩炴帴鍚庢煡璇㈠嚭鐨勭粨鏋滄槸56琛岃褰曘�備篃灏变綘鍙槸鎯冲湪鏌ヨemp琛ㄧ殑鍚屾椂锛屾妸姣忎釜鍛樺伐鐨勬墍鍦ㄩ儴闂ㄤ俊鎭樉绀哄嚭鏉ワ紝閭ｄ箞灏遍渶瑕佷娇鐢ㄤ富澶栭敭鏉ュ幓闄ゆ棤鐢ㄤ俊鎭簡銆�
浣跨敤涓诲閿叧绯诲仛涓烘潯浠舵潵鍘婚櫎鏃犵敤淇℃伅
SELECT * FROM emp,dept WHERE emp.deptno=dept.deptno;
娉細鍦ㄥ琛ㄦ煡璇腑锛屽湪浣跨敤鍒楁椂蹇呴』鎸囧畾鍒楁墍浠庡睘鐨勮〃锛屼緥濡俥mp.deptno琛ㄧずemp琛ㄧ殑deptno鍒椼��
锛�1锛夊唴杩炴帴
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SELECT *
FROM emp e Inner JOIN dept d
ON聽e.deptno=d.deptno;
鐗圭偣锛氭煡璇㈢粨鏋滃繀椤绘弧瓒虫潯浠讹紝涓や釜琛ㄤ腑閮芥湁鐨勬暟鎹墠浼氭樉绀哄嚭鏉�
鑷繛鎺�锛氭妸鍚屼竴寮犺〃褰撳仛澶氬紶琛ㄥ寰�(鐗规畩鍐呰繛鎺�)
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鎵�浠ュ鏋滄瘮杈冩潯浠舵槸鍚屼竴寮犺〃鍐呬笉鍚岃鐨勬暟鎹娇鐢ㄨ嚜杩炴帴锛屽皢涓�寮犺〃鎷疯礉涓�浠�
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FROM emp e1, emp e2
WHERE e1.mgr = e2.empno ANDe1.empno = 7369;
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宸﹀杩炴帴锛氬乏杈瑰熀纭�琛� 聽 聽 鍙冲杩炴帴锛氬彸杈瑰熀纭�琛�
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SELECT <鍒楀悕>
FROM TABLE1 LEFT | RIGHT JOIN TABLE2
ON TABLE1.鍒�=TABLE2.鍒�
杩炴帴鍚庣殑琛ㄦ槸涓や釜琛ㄧ瑳鍗″皵绉殑缁撴灉锛屾敞鎰忎娇鐢ㄤ富澶栭敭鍏崇郴鍘婚櫎涓嶉渶瑕佺殑璁板綍
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SELECT * FROM emp NATURAL JOIN dept; 聽 聽//鍐呰繛鎺�
SELECT * FROM emp NATURAL LEFT JOIN dept; 聽 聽//宸﹂摼鎺�
SELECT * FROM emp NATURAL RIGHT JOIN dept; 聽 聽//鍙抽摼鎺�
锛�4锛夊瓙鏌ヨ锛堥噸鐐癸級
涓�涓猻elect璇彞涓寘鍚彟涓�涓畬鏁寸殑select璇彞銆�
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姹傛瘡涓粍閲屾渶澶у伐璧勭殑鍛樺伐
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瀛愭煡璇㈠父鍑虹幇鐨勪綅缃�锛�
where鍚庯紝浣滀负琚煡璇㈢殑涓�鏉′欢鐨勪竴閮ㄥ垎锛�
from鍚庯紝浣滆〃锛�
飪� 鍗曡鍗曞垪锛堢敤浜庢潯浠讹級
飪� 鍗曡澶氬垪锛堢敤浜庢潯浠讹級
飪� 澶氳鍗曞垪锛堢敤浜庢潯浠讹級
飪� 澶氳澶氬垪锛堢敤浜庤〃锛屽垎缁勶級
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