{"id":194072,"date":"2020-11-01T11:36:15","date_gmt":"2020-11-01T03:36:15","guid":{"rendered":"http:\/\/4563.org\/?p=194072"},"modified":"2020-11-01T11:36:15","modified_gmt":"2020-11-01T03:36:15","slug":"mysql%ef%bc%9a%e8%81%94%e5%90%88%e7%b4%a2%e5%bc%95%e5%9c%a8%e4%ba%8c%e7%ba%a7%e7%b4%a2%e5%bc%95%e4%b8%ad%e6%98%af%e5%a6%82%e4%bd%95%e5%ad%98%e5%82%a8%e7%9a%84","status":"publish","type":"post","link":"http:\/\/4563.org\/?p=194072","title":{"rendered":"MySQL\uff1a\u8054\u5408\u7d22\u5f15\u5728\u4e8c\u7ea7\u7d22\u5f15\u4e2d\u662f\u5982\u4f55\u5b58\u50a8\u7684"},"content":{"rendered":"
\n
\n
\n

MySQL\uff1a\u8054\u5408\u7d22\u5f15\u5728\u4e8c\u7ea7\u7d22\u5f15\u4e2d\u662f\u5982\u4f55\u5b58\u50a8\u7684 <\/h1>\n

<\/p>\n

\n
\u8cc7\u6df1\u5927\u4f6c : douya0808 <\/span> <\/i> 3<\/span> <\/div>\n
<\/div>\n<\/p><\/div>\n<\/p><\/div>\n<\/p><\/div>\n
<\/p>\n

\u8868 T \u5305\u542b\u8054\u5408\u7d22\u5f15 (A, B) \u548c\u4e09\u4e2a\u4e8c\u7ea7\u7d22\u5f15 (C)\u3001(C, A) \u548c (C, B)
CREATE\u00a0TABLE\u00a0T\u00a0(
\u2003\u2003A\u00a0INT(11),\u00a0
\u2003\u2003B\u00a0INT(11),\u00a0
\u2003\u2003C\u00a0INT(11),\u00a0
\u2003\u2003PRIMARY\u00a0KEY\u00a0(A,\u00a0B),\u00a0
\u2003\u2003KEY\u00a0C\u00a0(C),\u00a0
\u2003\u2003KEY\u00a0CA\u00a0(C,\u00a0A),\u00a0
\u2003\u2003KEY\u00a0CB\u00a0(C,\u00a0B)\u00a0
);
\u4e3a\u4e86\u80fd\u591f\u8fdb\u884c\u56de\u8868\u67e5\u8be2\uff0c\u4e8c\u7ea7\u7d22\u5f15\u4f1a\u4fdd\u5b58\u805a\u7c07\u7d22\u5f15\u7684\u503c\uff0c\u4f46\u5f53\u805a\u7c07\u7d22\u5f15\u4e3a\u8054\u5408\u7d22\u5f15\u65f6\uff0c\u4e09\u4e2a\u4e8c\u7ea7\u7d22\u5f15\u5206\u522b\u662f\u600e\u6837\u4fdd\u5b58\u805a\u7c07\u7d22\u5f15\u7684\uff1f\u96be\u9053\u4e5f\u662f\u5c06\u805a\u7c07\u7d22\u5f15\u8ffd\u52a0\u5230\u4e8c\u7ea7\u7d22\u5f15\u540e\u9762\uff0c\u5c06 (C) \u4fdd\u5b58\u4e3a (C, A, B)\uff0c(C, A) \u4fdd\u5b58\u4e3a (C, A, A, B)\uff0c(C, B) \u4fdd\u5b58\u4e3a (C, B, A, B) \u5417\uff1f<\/p>\n<\/p><\/div>\n

\u5927\u4f6c\u6709\u8a71\u8aaa<\/b> (3<\/span>) <\/div>\n
<\/div>\n<\/p><\/div>\n<\/p><\/div>\n
    \n
  • \n
    \n
    \n
    \u8cc7\u6df1\u5927\u4f6c : xiangyuecn <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    \u89c6\u89c9\u4e0a\uff0c\u5efa CB \u5c31\u53ef\u4ee5\u4e86\uff0cC \u3001CA \u591a\u4f59\uff0c\u8bf4\u4e0d\u5b9a\u6570\u636e\u5e93\u5c31\u662f\u6309\u4f60\u8bf4\u7684\u8fd9\u6837\u5b58\u7684 <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
    \n
    \u8cc7\u6df1\u5927\u4f6c : geebos <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    \u786e\u5b9e\u662f\u8fd9\u6837\uff0c\u56e0\u4e3a\u4e8c\u7ea7\u7d22\u5f15\u8981\u6839\u636e\u4e3b\u952e\u624d\u80fd\u56de\u8868\u67e5\u8be2 <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
    \n
    \u4e3b<\/span> \u8cc7\u6df1\u5927\u4f6c : douya0808 <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    @xiangyuecn
    \u4f3c\u4e4e\u786e\u5b9e\u5982\u60a8\u6240\u8bf4
    \u6211\u770b\u7b54\u6848\u4e2d (C) \u4f1a\u8ffd\u52a0\u4e3b\u952e\u6210\u4e3a (C, A, B)\uff0c(C, A) \u4e2d\u7531\u4e8e\u5df2\u6709 A\uff0c\u6545\u4ec5\u8ffd\u52a0 B \u6210\u4e3a (C, A, B)\uff0c(C, B) \u4e2d\u5df2\u6709 B\uff0c\u6545\u4ec5\u8ffd\u52a0 A \u6210\u4e3a (C, B, A)\uff0c\u4f46\u662f\u5e76\u4e0d\u77e5\u9053\u662f\u9075\u5faa\u4ec0\u4e48\u6837\u7684\u89c4\u5219\uff0c\u7f51\u4e0a\u7684\u5927\u90e8\u5206\u6587\u7ae0\u90fd\u662f\u8ffd\u52a0\u7684\u5355\u5b57\u6bb5\u7d22\u5f15\uff0c\u6ca1\u6709\u4ecb\u7ecd\u4e3b\u952e\u4e3a\u8054\u5408\u7d22\u5f15\u65f6\u4e8c\u7ea7\u7d22\u5f15\u662f\u4ee5\u4ec0\u4e48\u89c4\u5219\u8ffd\u52a0\u7684 <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n","protected":false},"excerpt":{"rendered":"

    MySQL\uff1a\u8054\u5408\u7d22\u5f15\u5728\u4e8c\u7ea7\u7d22\u5f15\u4e2d\u662f…<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[],"tags":[],"_links":{"self":[{"href":"http:\/\/4563.org\/index.php?rest_route=\/wp\/v2\/posts\/194072"}],"collection":[{"href":"http:\/\/4563.org\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/4563.org\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/4563.org\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/4563.org\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=194072"}],"version-history":[{"count":0,"href":"http:\/\/4563.org\/index.php?rest_route=\/wp\/v2\/posts\/194072\/revisions"}],"wp:attachment":[{"href":"http:\/\/4563.org\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=194072"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/4563.org\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=194072"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/4563.org\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=194072"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}