sql用命令创建主键与外键，怎么操作？ sql的主键和外键怎么设?
sql\u7528\u547d\u4ee4\u521b\u5efa\u4e3b\u952e\u4e0e\u5916\u952e\u30021\u3001\u4e3a\u4e86\u65b9\u4fbf\u5927\u5bb6\u7406\u89e3\uff0c\u4f7f\u7528\u4e00\u4e2a\u4f8b\u5b50\u6765\u5e2e\u52a9\u5927\u5bb6\u7406\u89e3\u3002\u610f\u601d\u5927\u6982\u5c31\u662f\u901a\u8fc7\u5f15\u7528\u8868\u4e8c\u4e2d\u7684\u5b57\u6bb5\u5b8c\u6210\u5bf9\u8868\u4e00\u5b57\u6bb5\u7684\u7ea6\u675f\u3002\u65b9\u6cd5\uff1a
2\u3001\u8fd9\u91cc\u4e00\u5171\u4e24\u4e2a\u8868\uff0c\u5148\u521b\u5efa\u5916\u952e\u8868\uff0c\u56e0\u4e3a\u5148\u6709\u5916\u952e\uff0c\u4e3b\u952e\u624d\u80fd\u5f15\u7528\u3002\u9996\u5148\u521b\u5efa\u6570\u636e\u5e93\uff0c\u65b0\u5efa\u67e5\u8be2\u3002
3\u3001\u65b0\u5efa\u5916\u952e\u8868\u3010teacher\u3011\uff0c\u8f93\u5165\u547d\u4ee4\uff1acreate table teacher\u3002\u6dfb\u52a0\u9700\u8981\u7684\u5b57\u6bb5teacher_xingming\u5e76\u8bbe\u7f6e\u5b83\u4e3a\u3010\u4e3b\u952e\u3011\u3002\u8f93\u5165\u547d\u4ee4\uff1ateacher_xingming nchar(10) primary key,
4\u3001\u9009\u4e2d\u9700\u8981\u6267\u884c\u7684\u547d\u4ee4\u884c\uff0c\u5355\u51fb\u3010\u6267\u884c\u3011\uff0c\u4e0b\u65b9\u4f1a\u6709\u662f\u5426\u6210\u529f\u7684\u63d0\u793a\u3002\u73b0\u5728\u5bf9\u8868\u8fdb\u884c\u5237\u65b0\u64cd\u4f5c\u540e\uff0c\u4f1a\u53d1\u73b0\u5df2\u7ecf\u6210\u529f\u521b\u5efa\u4e86\u4e00\u4e2a\u65b0\u8868\u3010teacher\u3011\u3002
5\u3001\u63a5\u4e0b\u6765\u5c31\u8981\u521b\u5efa\u5b66\u751f\u8868\u4e86,create table student(student_xingming nchar(10) primary key not null,\u2014\u2014\u8be5\u7a0b\u5e8f\u6bb5\u610f\u601d\u4e3a\u521b\u5efa\u4e00\u4e2a\u3010student\u3011\u8868\uff0c\u8868\u4e2d\u65b0\u5efa\u4e00\u4e2a\u4e3b\u952e\u3010student_xingming\u5b57\u6bb5\uff0c\u7c7b\u578b\u4e3anchar(10) \uff0c\u5e76\u4e0d\u5141\u8bb8\u4e3a\u7a7a\u3002\u3011
6\u3001\u7ee7\u7eed\u5199\uff0c\u8f93\u5165\uff1astudent_banji nchar(10) not null,\u2014\u2014\u8868\u4e2d\u65b0\u5efa\u4e00\u4e2a\u3010student_banji\u5b57\u6bb5\uff0c\u7c7b\u578b\u4e3anchar(10) \uff0c\u5e76\u4e0d\u5141\u8bb8\u4e3a\u7a7a\u3002\u3011
7\u3001\u521b\u5efa\u5916\u952e\uff0c\u8f93\u5165\u547d\u4ee4student_jiaoshi nchar(10) foreign key references teacher(teacher_xingming)\u770b\u8d77\u6765\u5f88\u957f\uff0c\u5b9e\u9645\u610f\u601d\u5f88\u7b80\u5355\uff1a\u8868\u4e2d\u65b0\u5efa\u4e00\u4e2a\u3010student_jiaoshi\u5b57\u6bb5\u3011\uff0c\u5b83\u662f\u5916\u952e\uff0cnchar(10)\u7c7b\u578b\uff0c\u5b83\u6765\u81f3 teacher_xingming\u4e2d\u7684\u5185\u5bb9\u3002
8\u3001\u9009\u4e2d\uff0c\u70b9\u51fb\u3010\u6267\u884c\u3011\uff0c\u6ca1\u6709\u9519\u8bef\uff0c\u5c31\u8bf4\u660e\u6210\u529f\u4e86\u3002\u5237\u65b0\u4e00\u4e0b\u8868\uff0c\u770b\u770b\u662f\u4e0d\u662f\u591a\u4e86\u4e00\u4e2a\u8868\u3010student\u3011\uff1f\u6240\u6709\u7ea6\u675f\u5df2\u7ecf\u521b\u5efa\u597d\u4e86\u3002
9\u3001\u6765\u8bd5\u4e00\u4e0b\u770b\u770b\u662f\u5426\u771f\u6b63\u5b9e\u73b0\u6240\u8bf4\u7684\u529f\u80fd\u3002\u6253\u5f00\u3010teacher\u8868\u3011\uff0c\u586b\u5199\u201c\u5218\u8001\u5e08\u201d\u3002\u6253\u5f00\u3010student\u8868\u3011\uff0c\u524d\u9762\u4efb\u610f\u586b\uff0c\u6700\u540e\u586b\u5199\u201c\u5218\u8001\u5e08\u201d\uff0c\u6ca1\u6709\u9519\u8bef\u8bf4\u660e\u6ca1\u95ee\u9898\u3002
10\u3001\u5982\u4f55\u60f3\u6d4b\u8bd5\u7ea6\u675f\u662f\u5426\u771f\u7684\u6709\u6548\uff0c\u586b\u5199\u5176\u4ed6\u5185\u5bb9\uff0c\u770b\u770b\u662f\u5426\u6210\u529f\uff0c\u53ea\u8981\u4e0d\u662f\u3010teacher\u3011\u5b57\u6bb5\u4e2d\u7684\u5185\u5bb9\uff0c\u4ed6\u5c31\u4f1a\u62a5\u9519\u3002
用命令创建主键与外键方法如下：
绛旓細add constraint PK_瀛楁鍚--"PK"涓轰富閿殑缂╁啓锛屽瓧娈靛悕涓鸿鍦ㄥ叾涓鍒涘缓涓婚敭鐨瀛楁鍚,'PK_瀛楁鍚'灏变负绾︽潫鍚 primary key (瀛楁鍚) --瀛楁鍚嶅悓涓 --鍞竴绾︽潫:alter table 琛ㄥ悕 add constraint UQ_瀛楁鍚 unique (瀛楁鍚)--澶栭敭绾︽潫锛歛lter table 琛ㄥ悕 add constraint FK_瀛楁鍚--"FK"涓澶栭敭鐨...
绛旓細--鐢ㄥ懡浠ゅ垱寤轰富閿笌澶栭敭.--浣跨敤SQL璇彞鍒涘缓涓婚敭绾︽潫鍙互鍦ㄥ垱寤鸿〃锛圕reateTable锛夋垨淇敼琛紙AlterTable锛夋椂杩涜 鍒涘缓銆--渚嬪垱寤鸿〃鏃 createtabletablename (idint(CONSTRAINTpk_id)PRIMARYKEY )--渚嬩慨鏀硅〃鏃 ALTERTABLEtablename --淇敼琛 ADD CONSTRAINTtb_PRIMARY PRIMARYKEYCLUSTERED(鍒楀悕)/*灏嗕綘瑕佽...
绛旓細1銆佷负浜嗘柟渚垮ぇ瀹剁悊瑙ｏ紝浣跨敤涓涓緥瀛愭潵甯姪澶у鐞嗚В銆傛剰鎬濆ぇ姒傚氨鏄氳繃寮曠敤琛ㄤ簩涓殑瀛楁瀹屾垚瀵硅〃涓瀛楁鐨勭害鏉熴傛柟娉曪細2銆佽繖閲屼竴鍏变袱涓〃锛屽厛鍒涘缓澶栭敭琛紝鍥犱负鍏堟湁澶栭敭锛屼富閿鎵嶈兘寮曠敤銆傞鍏堝垱寤烘暟鎹簱锛屾柊寤烘煡璇3銆鏂板缓澶栭敭琛ㄣ恡eacher銆戯紝杈撳叆鍛戒护锛歝reate table teacher銆傛坊鍔犻渶瑕佺殑瀛楁teacher_xingming骞惰...
绛旓細1.涓轰簡甯姪浣犵悊瑙ｏ紝鐢ㄤ竴涓緥瀛愭潵甯姪浣犵悊瑙ｃ傚畠鍩烘湰涓婃槸鎸囬氳繃寮曠敤琛2涓殑瀛楁鏉ョ害鏉熻〃1涓殑瀛楁銆2.鏈変袱涓〃锛岀涓涓〃鍒涘缓澶栭敭琛紝鍥犱负绗竴涓澶栭敭锛屼富閿鍙互琚紩鐢ㄣ傞鍏堝垱寤烘暟鎹簱锛岀劧鍚庡垱寤轰竴涓柊鐨勬煡璇3.鍒涘缓涓涓柊鐨勫閿〃[teacher]锛岀劧鍚庤緭鍏鍛戒护:Createtableteacher銆傛坊鍔爐eacher_xingming鐨...
绛旓細鎴戜滑棣栧厛鏉鏂板缓涓涓涓婚敭琛紝濡備笅锛氱劧鍚庢垜浠墽琛屽畠锛屽涓嬶細鐒跺悗鎴戜滑鍐嶆潵閿閿〃锛屽涓嬶細杩欓噷SQL鍛戒护鐨勯噸鐐规槸璁剧疆澶栭敭鐨勯儴鍒嗭細 dept_id int constraint fk_dept_id_hjj foreign key references dept1(dept_id) ) 娉細鈥渇oreign key鈥濊〃绀澶栭敭锛鈥渞eferences鈥濇槸鍙傜収鐨勬剰鎬濓紝鍚庨潰璺熺潃鐨勬槸涓婚敭琛ㄧ殑鍚嶇О鍜...
绛旓細1銆侀鍏堟垜浠墦寮鏁版嵁搴撹〃锛屾壘鍒拌寤虹珛澶栭敭鐨琛ㄣ傚苟瑕佺‘淇濊寤虹珛澶栭敭鍏崇郴鐨勫垪涓涓婚敭琛ㄤ腑鐨勬暟鎹被鍨嬪畬鍏ㄧ浉鍚屻2銆佺劧鍚庢垜浠湪瑕佸缓绔嬪閿叧绯荤殑琛ㄤ腑锛屽彸鍑诲叧绯伙紝鍦ㄥ閿叧绯诲璇濇涓紝鐐瑰嚮宸︿笅瑙掔殑娣诲姞锛屾帴鐫鐐瑰嚮銆愯〃鍜屽垪瑙勮寖銆戦」鐨勫彸渚х殑灏忔寜閽紝鍦ㄨ〃鍜屽垪瀵硅瘽妗嗕腑锛屽湪涓婚敭琛ㄤ笅鏂归夋嫨澶栭敭鍒楁墍鍦ㄧ殑琛ㄥ拰璇...
绛旓細-- 涓婚敭:alter table 琛ㄥ悕 add constraint PK_瀛楁鍚--"PK"涓轰富閿殑缂╁啓锛屽瓧娈靛悕涓鸿鍦ㄥ叾涓鍒涘缓涓婚敭鐨瀛楁鍚,'PK_瀛楁鍚'灏变负绾︽潫鍚 primary key (瀛楁鍚) --瀛楁鍚嶅悓 --鍞竴绾︽潫:alter table 琛ㄥ悕 add constraint UQ_瀛楁鍚 unique (瀛楁鍚 --澶栭敭绾︽潫锛歛lter table 琛ㄥ悕 add constraint ...
绛旓細1銆鍒涘缓娴嬭瘯涓昏〃锛堢彮绾ц〃test_class锛夛紝create table test_class(class_id number, class_name varchar2(20));2銆佸垱寤烘祴璇曞瓙琛紙瀛︾敓琛╰est_student锛夛紝create table test_student(stu_id number, stu_name varchar2(200), class_id number);3銆佷富琛紙鐝骇琛╰est_class锛夋坊鍔犲敮涓涓婚敭锛alter table...
绛旓細鍏堝缓涓昏〃 creat table pp (sno int primary key,sname varchar(6))鍐嶅缓浠庤〃 creat table pp1 (sno1 int foreign key references pp(sno),sname varchar(6))鍏朵腑琛╬p涓殑sno灏辨槸pp鐨勪富閿紝涓婚敭鐨灞炴у间笉鍙负绌猴紝涓斿湪琛ㄤ腑涓嶅彲閲嶅 琛╬p1涓殑sno1灏辨槸pp1涓鐨勫閿 澶栭敭 (FK) 鏄敤浜寤虹珛...
绛旓細1.涓婚敭璇硶 鈶鍒涘缓鏃讹細create table sc (studentno int,courseid int,score int,primary key (studentno) );鈶′慨鏀规椂锛欰LTER TABLE table_name ADD CONSTRAINT pk_name PRIMARY KEY(鍒楀悕);鍓嶆彁鏄師鍏堟病鏈夎缃富閿2.澶栭敭璇硶 鈶犲垱寤烘椂锛歝reate table sc (studentno int,courseid int,score int,...
