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SQL Server shu ju ku lian jie cha xun de zhong lei ji qi ying yong

2008-07-10 05:54:08 编辑來源:互联网 评论
 
本文为【SQL Server数据库连接查询的种类及其应用】的拼音翻译版
  zai shu ju ku kai fa fang mian , tong guo dan biao suo biao xian de shi xian , you shi hou xu yao zu he cha xun lai zhao dao wo men xu yao de ji lu ji , zhe shi hou wo men jiu hui yong dao lian jie cha xun 。
  lian jie cha xun zhu yao bao kuo yi xia ji ge fang mian :
  nei lian jie
  nei lian jie yi ban shi wo men zui chang shi yong de , ye jiao zi ran lian jie , shi yong bi jiao yun suan fu bi jiao yao lian jie lie de zhi de lian jie 。 ta shi tong guo (INNER JOIN huo zhe JOIN) guan jian zi ba duo biao jin xing lian jie 。 wo men tong guo jian li liang ge biao lai shuo ming wen ti :
  StudentID StudentName StudentAge
  ----------- ----------------- -----------
  1 zhang san 25
  2 li si 26
  3 wang wu 27
  4 zhao liu 28
  5 wu ming shi 27
  yi shang shi biao Student, cun fang xue sheng ji ben xin xi 。
  BorrowBookID BorrowBookName StudentID BorrowBookPublish
  -------------------
  1 ma ke si zhu yi zheng zhi jing ji xue 1 dian zi gong ye chu ban she
  2 mao ze dong si xiang gai lun 2 gao deng jiao yu chu ban she
  3 deng xiao ping li lun 3 ren min you dian chu ban she
  4 da xue sheng si xiang dao de xiu yang 4 zhong guo tie dao chu ban she
  5 C yu yan cheng xu she ji NULL gao deng jiao yu chu ban she
  yi shang shi biao BorrowBook, cun fang xue sheng suo jie de shu 。
  yi shang liang zhang biao shi tong guo StudentID jin xing guan lian , zai zhe li xian zhi xing nei lian lian yu ju :
  Select Student.StudentName,Student.StudentAge,BorrowBook.BorrowBookName,BorrowBook.BorrowBookPublish
  From Student
  Inner Join BorrowBook
  On Student.StudentID = BorrowBook.StudentID
  shang mian zhe ge yu ju ye ke yi xie cheng
  Select Student.StudentName,Student.StudentAge,BorrowBook.BorrowBookName,BorrowBook.BorrowBookPublish
  FROM Student,BorrowBook
  WHERE Student.StudentID = BorrowBook.StudentID
  qi zhong ,Inner Join shi SQL Server de que sheng lian jie , ke jian xie wei Join。 zai Join hou mian zhi ding ju ti de biao zuo lian jie 。On hou mian zhi ding le lian jie de tiao jian 。
  yun xing de jie guo ru xia :
  tudentName StudentAge BorrowBookName BorrowBookPublish
  --------------
  zhang san 25 ma ke si zhu yi zheng zhi jing ji xue dian zi gong ye chu ban she
  li si 26 mao ze dong si xiang gai lun gao deng jiao yu chu ban she
  wang wu 27 deng xiao ping li lun ren min you dian chu ban she
  zhao liu 28 da xue sheng si xiang dao de xiu yang zhong guo tie dao chu ban she
  ( suo ying xiang de xing shu wei 4 xing )
  gen ju cha xun de jie guo lai jin xing fen xi :
  ru guo duo ge biao yao zuo lian jie , na me zhe xie biao zhi jian bi ran cun zai zhe zhu jian he wai jian de guan xi 。 suo yi xu yao jiang zhe xie jian de guan xi lie chu , jiu ke yi de chu biao lian jie de jie guo 。 zai shang li zhong ,StudentID shi Student biao de zhu jian ,StudentID you shi BorrowBook biao de wai jian , zhe liang ge biao de lian jie tiao jian jiu shi Student.StudentID = BorrowBook.StudentID, dui bi cha xun jie guo ke yi de zhi , nei lian jie cha xun zhi cha xun chu zhu jian StudentID zai ling zhang biao zhong cun zai de ji lu , xiang Student biao zhong de di wu tiao ji lu , yin wei zai BorrowBook biao zhong StudentID bu cun zai , xiang BorrowBook biao zhong de di wu tiao ji lu StudentID wei Null, dui ying de Student biao zhong mei you ji lu , suo yi jiu bu hui xian shi 。 suo yi nei lian jie jiu shi jiang shen yu de shu ju biao zhong de mei lie yu qi ta shu ju biao de lie xiang pi pei , xing cheng lin shi shu ju biao , bing jiang man zu shu ju xiang xiang deng de ji lu cong lin shi shu ju biao zhong xuan ze chu lai 。
  nei lian jie cha xun cao zuo lie chu yu lian jie tiao jian pi pei de shu ju xing , ta shi yong bi jiao yun suan fu bi jiao bei lian jie lie de lie zhi 。 nei lian jie fen san zhong :
  1) deng zhi lian jie : zai lian jie tiao jian zhong shi yong deng yu hao (=) yun suan fu bi jiao bei lian jie lie de lie zhi , qi cha xun jie guo zhong lie chu bei lian jie biao zhong de suo you lie , bao kuo qi zhong de chong fu lie 。
  2) bu deng lian jie : zai lian jie tiao jian shi yong chu deng yu yun suan fu yi wai de qi ta bi jiao yun suan fu bi jiao bei lian jie de lie de lie zhi 。 zhe xie yun suan fu bao kuo > 、> =、 <=、 <、!> 、! < he <> 。
  3) zi ran lian jie : zai lian jie tiao jian zhong shi yong deng yu (=) yun suan fu bi jiao bei lian jie lie de lie zhi , dan ta shi yong xuan ze lie biao zhi chu cha xun jie guo ji he zhong suo bao kuo de lie , bing shan chu lian jie biao zhong de chong fu lie 。
  li ru dui yu yong bu deng zhi lian jie yu ju :
  Select Student.StudentName,Student.StudentAge,BorrowBook.BorrowBookName,BorrowBook.BorrowBookPublish
  From Student
  Inner Join BorrowBook
  On Student.StudentID <> BorrowBook.StudentID
  StudentName StudentAge BorrowBookName BorrowBookPublish
  ----------------
  li si 26 ma ke si zhu yi zheng zhi jing ji xue dian zi gong ye chu ban she
  wang wu 27 ma ke si zhu yi zheng zhi jing ji xue dian zi gong ye chu ban she
  zhao liu 28 ma ke si zhu yi zheng zhi jing ji xue dian zi gong ye chu ban she
  wu ming shi 27 ma ke si zhu yi zheng zhi jing ji xue dian zi gong ye chu ban she
  zhang san 25 mao ze dong si xiang gai lun gao deng jiao yu chu ban she
  wang wu 27 mao ze dong si xiang gai lun gao deng jiao yu chu ban she
  zhao liu 28 mao ze dong si xiang gai lun gao deng jiao yu chu ban she
  wu ming shi 27 mao ze dong si xiang gai lun gao deng jiao yu chu ban she
  zhang san 25 deng xiao ping li lun ren min you dian chu ban she
  li si 26 deng xiao ping li lun ren min you dian chu ban she
  zhao liu 28 deng xiao ping li lun ren min you dian chu ban she
  wu ming shi 27 deng xiao ping li lun ren min you dian chu ban she
  zhang san 25 da xue sheng si xiang dao de xiu yang zhong guo tie dao chu ban she
  li si 26 da xue sheng si xiang dao de xiu yang zhong guo tie dao chu ban she
  wang wu 27 da xue sheng si xiang dao de xiu yang zhong guo tie dao chu ban she
  wu ming shi 27 da xue sheng si xiang dao de xiu yang zhong guo tie dao chu ban she
  ta jiu hui ba liang biao suo dui ying bu xiang deng de ji lu gei cha xun chu lai le 。
  wai lian jie
  wai lian jie zhu yao bao kuo zuo lian jie 、 you lian jie he wan zheng wai bu lian jie 。
  1) zuo lian jie :Left Join huo Left Outer Join
  zuo lian jie de jie guo ji bao kuo LEFT OUTER zi ju zhong zhi ding de zuo biao de suo you xing , er bu jin jin shi lian jie lie suo pi pei de xing 。 ru guo zuo biao de mou xing zai you biao zhong mei you pi pei xing , ze zai xiang guan lian de jie guo ji xing zhong you biao de suo you xuan ze lie biao lie yun wei kong zhi (Null)。
  wo men kan dui ying de SQL yu ju :
  Select Student.StudentName,Student.StudentAge,BorrowBook.BorrowBookName,BorrowBook.BorrowBookPublish
  From Student
  Left JOIN BorrowBook
  On Student.StudentID = BorrowBook.StudentID
  yun xing de jie guo ru xia :
  StudentName StudentAge BorrowBookName BorrowBookPublish
  ---------------
  zhang san 25 ma ke si zhu yi zheng zhi jing ji xue dian zi gong ye chu ban she
  li si 26 mao ze dong si xiang gai lun gao deng jiao yu chu ban she
  wang wu 27 deng xiao ping li lun ren min you dian chu ban she
  zhao liu 28 da xue sheng si xiang dao de xiu yang zhong guo tie dao chu ban she
  wu ming shi 27 NULL NULL
  ( suo ying xiang de xing shu wei 5 xing )
  ke yi kan dao de shi , ta cha xun de jie guo shi yi zuo biao Student wei zhu ,Student dui ying de StudentID zai you biao BorrowBook ru guo bu cun zai de hua , jiu hui yong NULL zhi lai dai ti 。
  2) you lian jie :Right Join huo Right Outer Join
  you lian jie he zuo lian jie xiang fan , ta jiang fan hui you biao de suo you xing 。 ru guo you biao de mou xing zai zuo biao zhong mei you pi pei xing , ze jiang wei zuo biao fan hui kong zhi (Null)。
  wo men kan dui ying de SQL yu ju
  Select Student.StudentName,Student.StudentAge,BorrowBook.BorrowBookName,BorrowBook.BorrowBookPublish
  From Student
  Right JOIN BorrowBook
  On Student.StudentID = BorrowBook.StudentID
  yun xing de jie guo ru xia :
  StudentName StudentAge BorrowBookName BorrowBookPublish
  -------------------
  zhang san 25 ma ke si zhu yi zheng zhi jing ji xue dian zi gong ye chu ban she
  li si 26 mao ze dong si xiang gai lun gao deng jiao yu chu ban she
  wang wu 27 deng xiao ping li lun ren min you dian chu ban she
  zhao liu 28 da xue sheng si xiang dao de xiu yang zhong guo tie dao chu ban she
  NULL NULL C yu yan cheng xu she ji gao deng jiao yu chu ban she
  ( suo ying xiang de xing shu wei 5 xing )
  ke yi kan dao de shi , ta cha xun de jie guo shi yi you biao BorrowBook wei zhu ,BorrowBook dui ying de StudentID zai zuo biao Student ru guo bu cun zai de hua , jiu hui yong NULL zhi lai dai ti 。
  3) wan zheng wai bu lian jie :Full Join huo Full Outer Join
  wan zheng wai bu lian jie fan hui zuo biao he you biao zhong de suo you xing 。 dang mou xing zai ling yi ge biao zhong mei you pi pei xing shi , ze ling yi ge biao de xuan ze lie biao lie bao han kong zhi 。 ru guo biao zhi jian you pi pei xing , ze zheng ge jie guo ji xing bao han ji biao de shu ju zhi 。
  wo men kan dui ying de SQL yu ju
  Select Student.StudentName,Student.StudentAge,BorrowBook.BorrowBookName,BorrowBook.BorrowBookPublish
  From Student
  FULL OUTER JOIN BorrowBook
  On Student.StudentID = BorrowBook.StudentID
  jie guo ru xia :
  StudentName StudentAge BorrowBookName BorrowBookPublish -------------------
  NULL NULL C yu yan cheng xu she ji gao deng jiao yu chu ban she
  zhang san 25 ma ke si zhu yi zheng zhi jing ji xue dian zi gong ye chu ban she
  li si 26 mao ze dong si xiang gai lun gao deng jiao yu chu ban she
  wang wu 27 deng xiao ping li lun ren min you dian chu ban she
  zhao liu 28 da xue sheng si xiang dao de xiu yang zhong guo tie dao chu ban she
  wu ming shi 27 NULL NULL
  ( suo ying xiang de xing shu wei 6 xing )
  ke yi kan dao de shi , ta cha xun de jie guo chu le ba xiang dui ying wan quan pi pei de ji lu cha chu lai yi hou , huan hui ba zuo lian jie ji you lian jie liang zhong qing xing dou bao kuo , dui ying de zhi yong NULL zhi lai dai ti 。
  jiao cha lian jie
  jiao cha lian jie (CROSS JOIN), jiu shi zhi bu dai W H E R E zi ju de cha xun 。 zai shu xue shang , jiu shi biao de di ka er ji 。 ye jiu shi ta cha xun chu lai de ji lu shu xing wei liang ge biao de cheng ji , dui ying ji lu ye jiu shi wei biao A* biao B。
  wo men kan dui ying de SQL yu ju
  Select Student.StudentName,Student.StudentAge,BorrowBook.BorrowBookName,BorrowBook.BorrowBookPublish
  From Student Cross Join BorrowBook
  yun xing de jie guo ru xia :
  StudentName StudentAge BorrowBookName BorrowBookPublish
  ---------------
  zhang san 25 ma ke si zhu yi zheng zhi jing ji xue dian zi gong ye chu ban she
  li si 26 ma ke si zhu yi zheng zhi jing ji xue dian zi gong ye chu ban she
  wang wu 27 ma ke si zhu yi zheng zhi jing ji xue dian zi gong ye chu ban she
  zhao liu 28 ma ke si zhu yi zheng zhi jing ji xue dian zi gong ye chu ban she
  wu ming shi 27 ma ke si zhu yi zheng zhi jing ji xue dian zi gong ye chu ban she
  zhang san 25 mao ze dong si xiang gai lun gao deng jiao yu chu ban she
  li si 26 mao ze dong si xiang gai lun gao deng jiao yu chu ban she
  wang wu 27 mao ze dong si xiang gai lun gao deng jiao yu chu ban she
  zhao liu 28 mao ze dong si xiang gai lun gao deng jiao yu chu ban she
  wu ming shi 27 mao ze dong si xiang gai lun gao deng jiao yu chu ban she
  zhang san 25 deng xiao ping li lun ren min you dian chu ban she
  li si 26 deng xiao ping li lun ren min you dian chu ban she
  wang wu 27 deng xiao ping li lun ren min you dian chu ban she
  zhao liu 28 deng xiao ping li lun ren min you dian chu ban she
  wu ming shi 27 deng xiao ping li lun ren min you dian chu ban she
  zhang san 25 da xue sheng si xiang dao de xiu yang zhong guo tie dao chu ban she
  li si 26 da xue sheng si xiang dao de xiu yang zhong guo tie dao chu ban she
  wang wu 27 da xue sheng si xiang dao de xiu yang zhong guo tie dao chu ban she
  zhao liu 28 da xue sheng si xiang dao de xiu yang zhong guo tie dao chu ban she
  wu ming shi 27 da xue sheng si xiang dao de xiu yang zhong guo tie dao chu ban she
  zhang san 25 C yu yan cheng xu she ji gao deng jiao yu chu ban she
  li si 26 C yu yan cheng xu she ji gao deng jiao yu chu ban she
  wang wu 27 C yu yan cheng xu she ji gao deng jiao yu chu ban she
  zhao liu 28 C yu yan cheng xu she ji gao deng jiao yu chu ban she
  wu ming shi 27 C yu yan cheng xu she ji gao deng jiao yu chu ban she
  ( suo ying xiang de xing shu wei 25 xing )
  ke yi kan dao de shi , ta ba biao Student zhong de mei yi xing he BorrowBook zhong de mei yi tiao ji lu dou jin xing guan lian , fan hui de ji lu shu wei 5*5=25 xing , ji di ka er ji , ta zhi xing de yu ju ye jiu deng xiao yu
  Select Student.StudentName,Student.StudentAge,BorrowBook.BorrowBookName,BorrowBook.BorrowBookPublish
  From Student,BorrowBook【原文】【汉音对照
 
 
 
 
 
 
 
 
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zai shu ju ku kai fa fang mian , tong guo dan biao suo biao xian de shi xian , you shi hou xu yao zu he cha xun lai zhao dao wo men xu yao de ji lu ji , zhe shi hou wo men jiu hui yong dao lian jie cha xun 。 lian jie cha xun zhu yao bao kuo yi xia ji ge fang mian : nei lian jie nei lian jie yi ban shi wo men zui chang shi yong de , ye jiao zi ran lian jie , shi yong bi jiao yun suan fu bi jiao yao lian jie lie de zhi de lian jie 。 ta shi tong guo (INNER JOIN huo zhe JOIN) guan jian zi ba duo biao jin xing lian jie 。 wo men tong guo jian li liang ge biao lai shuo ming wen ti : StudentID StudentName StudentAge ----------- ----------------- ----------- 1 zhang san 25 2 li si 26 3 wang wu 27 4 zhao liu 28 5 wu ming shi 27 yi shang shi biao Student, cun fang xue sheng ji ben xin xi 。 BorrowBookID BorrowBookName StudentID BorrowBookPublish ------------------- 1 ma ke si zhu yi zheng zhi jing ji xue 1 dian zi gong ye chu ban she 2 mao ze dong si xiang gai lun 2 gao deng jiao yu chu ban she 3 deng xiao ping li lun 3 ren min you dian chu ban she 4 da xue sheng si xiang dao de xiu yang 4 zhong guo tie dao chu ban she 5 C yu yan cheng xu she ji NULL gao deng jiao yu chu ban she yi shang shi biao BorrowBook, cun fang xue sheng suo jie de shu 。 yi shang liang zhang biao shi tong guo StudentID jin xing guan lian , zai zhe li xian zhi xing nei lian lian yu ju : Select Student.StudentName,Student.StudentAge,BorrowBook.BorrowBookName,BorrowBook.BorrowBookPublish From Student Inner Join BorrowBook On Student.StudentID = BorrowBook.StudentID shang mian zhe ge yu ju ye ke yi xie cheng Select Student.StudentName,Student.StudentAge,BorrowBook.BorrowBookName,BorrowBook.BorrowBookPublish FROM Student,BorrowBook WHERE Student.StudentID = BorrowBook.StudentID qi zhong ,Inner Join shi SQL Server de que sheng lian jie , ke jian xie wei Join。 zai Join hou mian zhi ding ju ti de biao zuo lian jie 。On hou mian zhi ding le lian jie de tiao jian 。 yun xing de jie guo ru xia : tudentName StudentAge BorrowBookName BorrowBookPublish -------------- zhang san 25 ma ke si zhu yi zheng zhi jing ji xue dian zi gong ye chu ban she li si 26 mao ze dong si xiang gai lun gao deng jiao yu chu ban she wang wu 27 deng xiao ping li lun ren min you dian chu ban she zhao liu 28 da xue sheng si xiang dao de xiu yang zhong guo tie dao chu ban she ( suo ying xiang de xing shu wei 4 xing ) gen ju cha xun de jie guo lai jin xing fen xi : ru guo duo ge biao yao zuo lian jie , na me zhe xie biao zhi jian bi ran cun zai zhe zhu jian he wai jian de guan xi 。 suo yi xu yao jiang zhe xie jian de guan xi lie chu , jiu ke yi de chu biao lian jie de jie guo 。 zai shang li zhong ,StudentID shi Student biao de zhu jian ,StudentID you shi BorrowBook biao de wai jian , zhe liang ge biao de lian jie tiao jian jiu shi Student.StudentID = BorrowBook.StudentID, dui bi cha xun jie guo ke yi de zhi , nei lian jie cha xun zhi cha xun chu zhu jian StudentID zai ling zhang biao zhong cun zai de ji lu , xiang Student biao zhong de di wu tiao ji lu , yin wei zai BorrowBook biao zhong StudentID bu cun zai , xiang BorrowBook biao zhong de di wu tiao ji lu StudentID wei Null, dui ying de Student biao zhong mei you ji lu , suo yi jiu bu hui xian shi 。 suo yi nei lian jie jiu shi jiang shen yu de shu ju biao zhong de mei lie yu qi ta shu ju biao de lie xiang pi pei , xing cheng lin shi shu ju biao , bing jiang man zu shu ju xiang xiang deng de ji lu cong lin shi shu ju biao zhong xuan ze chu lai 。 nei lian jie cha xun cao zuo lie chu yu lian jie tiao jian pi pei de shu ju xing , ta shi yong bi jiao yun suan fu bi jiao bei lian jie lie de lie zhi 。 nei lian jie fen san zhong : 1) deng zhi lian jie : zai lian jie tiao jian zhong shi yong deng yu hao (=) yun suan fu bi jiao bei lian jie lie de lie zhi , qi cha xun jie guo zhong lie chu bei lian jie biao zhong de suo you lie , bao kuo qi zhong de chong fu lie 。 2) bu deng lian jie : zai lian jie tiao jian shi yong chu deng yu yun suan fu yi wai de qi ta bi jiao yun suan fu bi jiao bei lian jie de lie de lie zhi 。 zhe xie yun suan fu bao kuo > 、> =、 <=、 <、!> 、! < he <> 。 3) zi ran lian jie : zai lian jie tiao jian zhong shi yong deng yu (=) yun suan fu bi jiao bei lian jie lie de lie zhi , dan ta shi yong xuan ze lie biao zhi chu cha xun jie guo ji he zhong suo bao kuo de lie , bing shan chu lian jie biao zhong de chong fu lie 。 li ru dui yu yong bu deng zhi lian jie yu ju : Select Student.StudentName,Student.StudentAge,BorrowBook.BorrowBookName,BorrowBook.BorrowBookPublish From Student Inner Join BorrowBook On Student.StudentID <> BorrowBook.StudentID StudentName StudentAge BorrowBookName BorrowBookPublish ---------------- li si 26 ma ke si zhu yi zheng zhi jing ji xue dian zi gong ye chu ban she wang wu 27 ma ke si zhu yi zheng zhi jing ji xue dian zi gong ye chu ban she zhao liu 28 ma ke si zhu yi zheng zhi jing ji xue dian zi gong ye chu ban she wu ming shi 27 ma ke si zhu yi zheng zhi jing ji xue dian zi gong ye chu ban she zhang san 25 mao ze dong si xiang gai lun gao deng jiao yu chu ban she wang wu 27 mao ze dong si xiang gai lun gao deng jiao yu chu ban she zhao liu 28 mao ze dong si xiang gai lun gao deng jiao yu chu ban she wu ming shi 27 mao ze dong si xiang gai lun gao deng jiao yu chu ban she zhang san 25 deng xiao ping li lun ren min you dian chu ban she li si 26 deng xiao ping li lun ren min you dian chu ban she zhao liu 28 deng xiao ping li lun ren min you dian chu ban she wu ming shi 27 deng xiao ping li lun ren min you dian chu ban she zhang san 25 da xue sheng si xiang dao de xiu yang zhong guo tie dao chu ban she li si 26 da xue sheng si xiang dao de xiu yang zhong guo tie dao chu ban she wang wu 27 da xue sheng si xiang dao de xiu yang zhong guo tie dao chu ban she wu ming shi 27 da xue sheng si xiang dao de xiu yang zhong guo tie dao chu ban she ta jiu hui ba liang biao suo dui ying bu xiang deng de ji lu gei cha xun chu lai le 。 wai lian jie wai lian jie zhu yao bao kuo zuo lian jie 、 you lian jie he wan zheng wai bu lian jie 。 1) zuo lian jie :Left Join huo Left Outer Join zuo lian jie de jie guo ji bao kuo LEFT OUTER zi ju zhong zhi ding de zuo biao de suo you xing , er bu jin jin shi lian jie lie suo pi pei de xing 。 ru guo zuo biao de mou xing zai you biao zhong mei you pi pei xing , ze zai xiang guan lian de jie guo ji xing zhong you biao de suo you xuan ze lie biao lie yun wei kong zhi (Null)。 wo men kan dui ying de SQL yu ju : Select Student.StudentName,Student.StudentAge,BorrowBook.BorrowBookName,BorrowBook.BorrowBookPublish From Student Left JOIN BorrowBook On Student.StudentID = BorrowBook.StudentID yun xing de jie guo ru xia : StudentName StudentAge BorrowBookName BorrowBookPublish --------------- zhang san 25 ma ke si zhu yi zheng zhi jing ji xue dian zi gong ye chu ban she li si 26 mao ze dong si xiang gai lun gao deng jiao yu chu ban she wang wu 27 deng xiao ping li lun ren min you dian chu ban she zhao liu 28 da xue sheng si xiang dao de xiu yang zhong guo tie dao chu ban she wu ming shi 27 NULL NULL ( suo ying xiang de xing shu wei 5 xing ) ke yi kan dao de shi , ta cha xun de jie guo shi yi zuo biao Student wei zhu ,Student dui ying de StudentID zai you biao BorrowBook ru guo bu cun zai de hua , jiu hui yong NULL zhi lai dai ti 。 2) you lian jie :Right Join huo Right Outer Join you lian jie he zuo lian jie xiang fan , ta jiang fan hui you biao de suo you xing 。 ru guo you biao de mou xing zai zuo biao zhong mei you pi pei xing , ze jiang wei zuo biao fan hui kong zhi (Null)。 wo men kan dui ying de SQL yu ju Select Student.StudentName,Student.StudentAge,BorrowBook.BorrowBookName,BorrowBook.BorrowBookPublish From Student Right JOIN BorrowBook On Student.StudentID = BorrowBook.StudentID yun xing de jie guo ru xia : StudentName StudentAge BorrowBookName BorrowBookPublish ------------------- zhang san 25 ma ke si zhu yi zheng zhi jing ji xue dian zi gong ye chu ban she li si 26 mao ze dong si xiang gai lun gao deng jiao yu chu ban she wang wu 27 deng xiao ping li lun ren min you dian chu ban she zhao liu 28 da xue sheng si xiang dao de xiu yang zhong guo tie dao chu ban she NULL NULL C yu yan cheng xu she ji gao deng jiao yu chu ban she ( suo ying xiang de xing shu wei 5 xing ) ke yi kan dao de shi , ta cha xun de jie guo shi yi you biao BorrowBook wei zhu ,BorrowBook dui ying de StudentID zai zuo biao Student ru guo bu cun zai de hua , jiu hui yong NULL zhi lai dai ti 。 3) wan zheng wai bu lian jie :Full Join huo Full Outer Join wan zheng wai bu lian jie fan hui zuo biao he you biao zhong de suo you xing 。 dang mou xing zai ling yi ge biao zhong mei you pi pei xing shi , ze ling yi ge biao de xuan ze lie biao lie bao han kong zhi 。 ru guo biao zhi jian you pi pei xing , ze zheng ge jie guo ji xing bao han ji biao de shu ju zhi 。 wo men kan dui ying de SQL yu ju Select Student.StudentName,Student.StudentAge,BorrowBook.BorrowBookName,BorrowBook.BorrowBookPublish From Student FULL OUTER JOIN BorrowBook On Student.StudentID = BorrowBook.StudentID jie guo ru xia : StudentName StudentAge BorrowBookName BorrowBookPublish ------------------- NULL NULL C yu yan cheng xu she ji gao deng jiao yu chu ban she zhang san 25 ma ke si zhu yi zheng zhi jing ji xue dian zi gong ye chu ban she li si 26 mao ze dong si xiang gai lun gao deng jiao yu chu ban she wang wu 27 deng xiao ping li lun ren min you dian chu ban she zhao liu 28 da xue sheng si xiang dao de xiu yang zhong guo tie dao chu ban she wu ming shi 27 NULL NULL ( suo ying xiang de xing shu wei 6 xing ) ke yi kan dao de shi , ta cha xun de jie guo chu le ba xiang dui ying wan quan pi pei de ji lu cha chu lai yi hou , huan hui ba zuo lian jie ji you lian jie liang zhong qing xing dou bao kuo , dui ying de zhi yong NULL zhi lai dai ti 。 jiao cha lian jie jiao cha lian jie (CROSS JOIN), jiu shi zhi bu dai W H E R E zi ju de cha xun 。 zai shu xue shang , jiu shi biao de di ka er ji 。 ye jiu shi ta cha xun chu lai de ji lu shu xing wei liang ge biao de cheng ji , dui ying ji lu ye jiu shi wei biao A* biao B。 wo men kan dui ying de SQL yu ju Select Student.StudentName,Student.StudentAge,BorrowBook.BorrowBookName,BorrowBook.BorrowBookPublish From Student Cross Join BorrowBook yun xing de jie guo ru xia : StudentName StudentAge BorrowBookName BorrowBookPublish --------------- zhang san 25 ma ke si zhu yi zheng zhi jing ji xue dian zi gong ye chu ban she li si 26 ma ke si zhu yi zheng zhi jing ji xue dian zi gong ye chu ban she wang wu 27 ma ke si zhu yi zheng zhi jing ji xue dian zi gong ye chu ban she zhao liu 28 ma ke si zhu yi zheng zhi jing ji xue dian zi gong ye chu ban she wu ming shi 27 ma ke si zhu yi zheng zhi jing ji xue dian zi gong ye chu ban she zhang san 25 mao ze dong si xiang gai lun gao deng jiao yu chu ban she li si 26 mao ze dong si xiang gai lun gao deng jiao yu chu ban she wang wu 27 mao ze dong si xiang gai lun gao deng jiao yu chu ban she zhao liu 28 mao ze dong si xiang gai lun gao deng jiao yu chu ban she wu ming shi 27 mao ze dong si xiang gai lun gao deng jiao yu chu ban she zhang san 25 deng xiao ping li lun ren min you dian chu ban she li si 26 deng xiao ping li lun ren min you dian chu ban she wang wu 27 deng xiao ping li lun ren min you dian chu ban she zhao liu 28 deng xiao ping li lun ren min you dian chu ban she wu ming shi 27 deng xiao ping li lun ren min you dian chu ban she zhang san 25 da xue sheng si xiang dao de xiu yang zhong guo tie dao chu ban she li si 26 da xue sheng si xiang dao de xiu yang zhong guo tie dao chu ban she wang wu 27 da xue sheng si xiang dao de xiu yang zhong guo tie dao chu ban she zhao liu 28 da xue sheng si xiang dao de xiu yang zhong guo tie dao chu ban she wu ming shi 27 da xue sheng si xiang dao de xiu yang zhong guo tie dao chu ban she zhang san 25 C yu yan cheng xu she ji gao deng jiao yu chu ban she li si 26 C yu yan cheng xu she ji gao deng jiao yu chu ban she wang wu 27 C yu yan cheng xu she ji gao deng jiao yu chu ban she zhao liu 28 C yu yan cheng xu she ji gao deng jiao yu chu ban she wu ming shi 27 C yu yan cheng xu she ji gao deng jiao yu chu ban she ( suo ying xiang de xing shu wei 25 xing ) ke yi kan dao de shi , ta ba biao Student zhong de mei yi xing he BorrowBook zhong de mei yi tiao ji lu dou jin xing guan lian , fan hui de ji lu shu wei 5*5=25 xing , ji di ka er ji , ta zhi xing de yu ju ye jiu deng xiao yu Select Student.StudentName,Student.StudentAge,BorrowBook.BorrowBookName,BorrowBook.BorrowBookPublish From Student,BorrowBook
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