{"id":5982,"date":"2024-11-14T08:12:52","date_gmt":"2024-11-14T00:12:52","guid":{"rendered":"https:\/\/fwq.ai\/blog\/5982\/"},"modified":"2024-11-14T08:12:52","modified_gmt":"2024-11-14T00:12:52","slug":"sql%e4%b8%adunique%e4%bb%80%e4%b9%88%e6%84%8f%e6%80%9d","status":"publish","type":"post","link":"https:\/\/fwq.ai\/blog\/5982\/","title":{"rendered":"sql\u4e2dunique\u4ec0\u4e48\u610f\u601d"},"content":{"rendered":"

\n \u5728 sql \u4e2d\uff0cunique \u7ea6\u675f\u786e\u4fdd\u4e00\u5217\u6216\u591a\u5217\u4e2d\u7684\u503c\u552f\u4e00\uff0c\u9632\u6b62\u91cd\u590d\u3002\u8981\u521b\u5efa unique \u7ea6\u675f\uff0c\u4f7f\u7528 alter table \u8bed\u53e5\u5e76\u6307\u5b9a\u8981\u7ea6\u675f\u7684\u5217\u3002unique \u7ea6\u675f\u7684\u597d\u5904\u5305\u62ec\u6570\u636e\u5b8c\u6574\u6027\u3001\u5feb\u901f\u67e5\u627e\u548c\u9632\u6b62\u6570\u636e\u91cd\u590d\u3002\u9700\u8981\u6ce8\u610f\u7684\u662f\uff0c\u5b83\u4e0d\u9002\u7528\u4e8e null \u503c\u3002\n<\/p><\/blockquote>\n

\"sql\u4e2dunique\u4ec0\u4e48\u610f\u601d\u63d2\u56fe\"<\/p>\n

SQL \u4e2d UNIQUE \u7684\u542b\u4e49<\/strong><\/p>\n

\u5728 SQL \u4e2d\uff0cUNIQUE \u7ea6\u675f\u7528\u4e8e\u786e\u4fdd\u4e00\u5217\u6216\u4e00\u7ec4\u5217\u4e2d\u7684\u503c\u552f\u4e00\u3002\u8fd9\u610f\u5473\u7740\u5bf9\u4e8e\u4efb\u4f55\u7279\u5b9a\u884c\uff0c\u8be5\u5217\u6216\u5217\u7ec4\u7684\u503c\u4e0e\u8868\u4e2d\u4efb\u4f55\u5176\u4ed6\u884c\u4e2d\u7684\u503c\u4e0d\u540c\u3002<\/p>\n

\u5982\u4f55\u4f7f\u7528 UNIQUE \u7ea6\u675f<\/strong><\/p>\n

\u8981\u521b\u5efa\u4e00\u4e2a UNIQUE \u7ea6\u675f\uff0c\u8bf7\u4f7f\u7528\u4ee5\u4e0b\u8bed\u6cd5\uff1a<\/p>\n

ALTER TABLE table_name ADD UNIQUE (column_name1, column_name2, ...);<\/pre>\n
  \u767b\u5f55\u540e\u590d\u5236   <\/p>\n
\u5176\u4e2d\uff1a<\/p>\n
    \n
  • table_name \u662f\u60a8\u8981\u521b\u5efa\u7ea6\u675f\u7684\u8868\u7684\u540d\u79f0\u3002<\/li>\n
  • column_name1\u3001column_name2 \u7b49\u662f\u60a8\u8981\u7ea6\u675f\u7684\u5217\u7684\u540d\u79f0\u3002<\/li>\n<\/ul>\n
    UNIQUE \u7ea6\u675f\u7684\u597d\u5904<\/strong><\/p>\n
    \u4f7f\u7528 UNIQUE \u7ea6\u675f\u5177\u6709\u4ee5\u4e0b\u597d\u5904\uff1a<\/p>\n
      \n
    •  \u6570\u636e\u5b8c\u6574\u6027\uff1a<\/strong>\u5b83\u786e\u4fdd\u8868\u4e2d\u6ca1\u6709\u91cd\u590d\u884c\uff0c\u4ece\u800c\u7ef4\u62a4\u6570\u636e\u5b8c\u6574\u6027\u3002<\/li>\n
    •  \u5feb\u901f\u67e5\u627e\uff1a<\/strong>\u5728\u552f\u4e00\u503c\u4e0a\u521b\u5efa\u7d22\u5f15\u65f6\uff0c\u5b83\u53ef\u4ee5\u52a0\u5feb\u67e5\u8be2\u901f\u5ea6\uff0c\u56e0\u4e3a\u6570\u636e\u5e93\u53ef\u4ee5\u5feb\u901f\u627e\u5230\u6240\u9700\u7684\u6570\u636e\u3002<\/li>\n
    •  \u9632\u6b62\u6570\u636e\u91cd\u590d\uff1a<\/strong>\u5b83\u9632\u6b62\u7528\u6237\u8f93\u5165\u91cd\u590d\u6570\u636e\uff0c\u4ece\u800c\u907f\u514d\u6570\u636e\u5197\u4f59\u548c\u9519\u8bef\u3002<\/li>\n<\/ul>\n
      \u5176\u4ed6\u6ce8\u610f\u4e8b\u9879<\/strong><\/p>\n
        \n
      • \u867d\u7136 UNIQUE \u7ea6\u675f\u786e\u4fdd\u503c\u552f\u4e00\uff0c\u4f46\u5b83\u4e0d\u9002\u7528\u4e8e NULL \u503c\u3002NULL \u503c\u88ab\u89c6\u4e3a\u4e0d\u540c\u7684\u503c\uff0c\u56e0\u6b64\u5b83\u4eec\u53ef\u4ee5\u91cd\u590d\u3002<\/li>\n
      • \u53ef\u4ee5\u5c06\u591a\u4e2a UNIQUE \u7ea6\u675f\u5e94\u7528\u4e8e\u540c\u4e00\u5f20\u8868\u3002<\/li>\n
      • \u5982\u679c\u8fdd\u53cd UNIQUE \u7ea6\u675f\uff0c\u5219\u4f1a\u5f15\u53d1\u9519\u8bef\uff0c\u5e76\u4e14\u8be5\u884c\u4e0d\u4f1a\u88ab\u63d2\u5165\u6216\u66f4\u65b0\u3002<\/li>\n
      • UNIQUE \u7ea6\u675f\u53ef\u4ee5\u968f\u65f6\u4f7f\u7528 ALTER TABLE \u8bed\u53e5\u6dfb\u52a0\u6216\u5220\u9664\u3002<\/li>\n<\/ul>\n
        \u4ee5\u4e0a\u5c31\u662fsql\u4e2dunique\u4ec0\u4e48\u610f\u601d\u7684\u8be6\u7ec6\u5185\u5bb9\uff0c\u66f4\u591a\u8bf7\u5173\u6ce8\u7c73\u4e91\u7f51\u5176\u5b83\u76f8\u5173\u6587\u7ae0\uff01<\/p>\n","protected":false},"excerpt":{"rendered":"
        \u5728 sql \u4e2d\uff0cunique \u7ea6\u675f\u786e\u4fdd\u4e00\u5217\u6216\u591a\u5217\u4e2d\u7684\u503c\u552f\u4e00\uff0c\u9632\u6b62\u91cd\u590d\u3002\u8981\u521b\u5efa unique \u7ea6\u675f\uff0c\u4f7f\u7528 alter table \u8bed\u53e5\u5e76\u6307\u5b9a\u8981\u7ea6\u675f\u7684\u5217\u3002unique \u7ea6\u675f\u7684\u597d\u5904\u5305\u62ec\u6570\u636e\u5b8c\u6574\u6027\u3001\u5feb\u901f\u67e5\u627e\u548c\u9632\u6b62\u6570\u636e\u91cd\u590d\u3002\u9700\u8981\u6ce8\u610f\u7684\u662f\uff0c\u5b83\u4e0d\u9002\u7528\u4e8e null \u503c\u3002 SQL \u4e2d UNIQUE \u7684\u542b\u4e49 \u5728 SQL \u4e2d\uff0cUNIQUE \u7ea6\u675f\u7528\u4e8e\u786e\u4fdd\u4e00\u5217\u6216\u4e00\u7ec4\u5217\u4e2d\u7684\u503c\u552f\u4e00\u3002\u8fd9\u610f\u5473\u7740\u5bf9\u4e8e\u4efb\u4f55\u7279\u5b9a\u884c\uff0c\u8be5\u5217\u6216\u5217\u7ec4\u7684\u503c\u4e0e\u8868\u4e2d\u4efb\u4f55\u5176\u4ed6\u884c\u4e2d\u7684\u503c\u4e0d\u540c\u3002 \u5982\u4f55\u4f7f\u7528 UNIQUE \u7ea6\u675f \u8981\u521b\u5efa\u4e00\u4e2a UNIQUE \u7ea6\u675f\uff0c\u8bf7\u4f7f\u7528\u4ee5\u4e0b\u8bed\u6cd5\uff1a ALTER TABLE table_name ADD UNIQUE (column_name1, column_name2, …); \u767b\u5f55\u540e\u590d\u5236 \u5176\u4e2d\uff1a table_name \u662f\u60a8\u8981\u521b\u5efa\u7ea6\u675f\u7684\u8868\u7684\u540d\u79f0\u3002 column_name1\u3001column_name2 \u7b49\u662f\u60a8\u8981\u7ea6\u675f\u7684\u5217\u7684\u540d\u79f0\u3002 UNIQUE \u7ea6\u675f\u7684\u597d\u5904 \u4f7f\u7528 UNIQUE \u7ea6\u675f\u5177\u6709\u4ee5\u4e0b\u597d\u5904\uff1a \u6570\u636e\u5b8c\u6574\u6027\uff1a\u5b83\u786e\u4fdd\u8868\u4e2d\u6ca1\u6709\u91cd\u590d\u884c\uff0c\u4ece\u800c\u7ef4\u62a4\u6570\u636e\u5b8c\u6574\u6027\u3002 \u5feb\u901f\u67e5\u627e\uff1a\u5728\u552f\u4e00\u503c\u4e0a\u521b\u5efa\u7d22\u5f15\u65f6\uff0c\u5b83\u53ef\u4ee5\u52a0\u5feb\u67e5\u8be2\u901f\u5ea6\uff0c\u56e0\u4e3a\u6570\u636e\u5e93\u53ef\u4ee5\u5feb\u901f\u627e\u5230\u6240\u9700\u7684\u6570\u636e\u3002 \u9632\u6b62\u6570\u636e\u91cd\u590d\uff1a\u5b83\u9632\u6b62\u7528\u6237\u8f93\u5165\u91cd\u590d\u6570\u636e\uff0c\u4ece\u800c\u907f\u514d\u6570\u636e\u5197\u4f59\u548c\u9519\u8bef\u3002 \u5176\u4ed6\u6ce8\u610f\u4e8b\u9879 \u867d\u7136 UNIQUE \u7ea6\u675f\u786e\u4fdd\u503c\u552f\u4e00\uff0c\u4f46\u5b83\u4e0d\u9002\u7528\u4e8e NULL \u503c\u3002NULL \u503c\u88ab\u89c6\u4e3a\u4e0d\u540c\u7684\u503c\uff0c\u56e0\u6b64\u5b83\u4eec\u53ef\u4ee5\u91cd\u590d\u3002 […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[16],"tags":[],"class_list":["post-5982","post","type-post","status-publish","format-standard","hentry","category-16"],"_links":{"self":[{"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/posts\/5982","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/comments?post=5982"}],"version-history":[{"count":0,"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/posts\/5982\/revisions"}],"wp:attachment":[{"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/media?parent=5982"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/categories?post=5982"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/tags?post=5982"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}