{"id":5989,"date":"2024-04-17T23:49:12","date_gmt":"2024-04-17T15:49:12","guid":{"rendered":"http:\/\/zyg.luchers.cn\/?p=5989"},"modified":"2024-04-17T23:49:12","modified_gmt":"2024-04-17T15:49:12","slug":"%e7%ac%ac%e4%b8%89%e7%ab%a0%e3%80%81%e6%95%b0%e6%8d%ae%e5%ba%93%e7%b3%bb%e7%bb%9f%ef%bc%886%e5%88%868%e5%88%86%ef%bc%89","status":"publish","type":"post","link":"http:\/\/zyg.luchers.cn\/index.php\/2024\/04\/17\/%e7%ac%ac%e4%b8%89%e7%ab%a0%e3%80%81%e6%95%b0%e6%8d%ae%e5%ba%93%e7%b3%bb%e7%bb%9f%ef%bc%886%e5%88%868%e5%88%86%ef%bc%89\/","title":{"rendered":"\u7b2c\u4e09\u7ae0\u3001\u6570\u636e\u5e93\u7cfb\u7edf\uff086\u5206~8\u5206\uff09"},"content":{"rendered":"

\u7b2c\u4e09\u7ae0\u3001\u6570\u636e\u5e93\u7cfb\u7edf\uff086\u5206~8\u5206\uff09<\/h1>\n

1\u3001\u4e3b\u8981\u8003\u8003\u5bdf<\/p>\n

\"image-20240219144537765\"<\/div><\/p>\n

2\u3001ER\u6a21\u578b\u6709\u4e00\u4e2a\u5927\u9898\uff0c15\u5206\u3002\u4e0b\u5348\u8003<\/p>\n

1\u3001\u4e09\u7ea7\u6a21\u5f0f-\u4e24\u5c42\u6620\u5c04<\/h2>\n

1\u3001\u4e09\u7ea7\u6a21\u5f0f<\/h3>\n
    \n
  • \u5916\u6a21\u5f0f\uff08\u89c6\u56fe\u7ea7\u522b\uff09\uff1a\u903b\u8f91\u7528\u6237<\/li>\n
  • \u6982\u5ff5\u6a21\u5f0f\uff08\u8868\u7ea7\uff09\uff1a\u6a21\u5f0f<\/li>\n
  • \u5185\u6a21\u5f0f\uff08\u6587\u4ef6\u7ea7\uff09\uff1a\u5b58\u50a8\u6a21\u5f0f\u3001\u4e3b\u8981\u662f\u7269\u7406\u5b58\u50a8<\/li>\n<\/ul>\n

    2\u3001\u4e24\u5c42\u6620\u5c04<\/h3>\n

    1\u3001\u5916\u6a21\u5f0f\u548c\u6982\u5ff5\u6a21\u5f0f\u7684\u6620\u5c04\uff08\u5916\u6a21\u5f0f\u6620\u5c04\uff09<\/p>\n

    2\u3001\u6982\u5ff5\u6a21\u5f0f\u548c\u5185\u6a21\u5f0f\u7684\u6620\u5c04\uff08\u5185\u6a21\u5f0f\u7684\u6620\u5c04\uff09<\/p>\n

    3\u3001\u8fd9\u4e2a\u72ec\u7acb\u662f\u4e3a\u4e86\u5c06\u6570\u636e\u72ec\u7acb\u3002<\/p>\n

    4\u3001\u7528\u6237\u53ea\u8981\u6539\u53d8\u6620\u5c04\u7684\u5173\u7cfb\uff0c\u4e0d\u9700\u8981\u7ba1\u4e0a\u5c42\u548c\u4e0b\u5c42\u3002<\/p>\n

    3\u3001\u5982\u56fe<\/h3>\n

    1\u3001

    \"image-20240219145143224\"<\/div><\/p>\n

    2\u3001\u6570\u636e\u5e93\u8bbe\u8ba1\u8fc7\u7a0b<\/h2>\n

    1\u3001\u56db\u4e2a\u9636\u6bb5<\/h3>\n

    1\u3001\u9700\u6c42\u5206\u6790<\/p>\n

      \n
    • \u4ea7\u51fa<\/li>\n
    • \u6570\u636e\u6d41\u56fe\uff1a\u6570\u636e\u7684\u6765\u9f99\u53bb\u8109\uff08\u4e0b\u5348\u5927\u9898\u4f1a\u800315\u5206\uff09<\/li>\n
    • \u6570\u636e\u5b57\u5178\uff1a\u5bf9\u6570\u636e\u6d41\u56fe\u7684\u8865\u5145<\/li>\n
    • \u9700\u6c42\u89c4\u683c\u8bf4\u660e\u4e66<\/li>\n<\/ul>\n

      2\u3001\u6982\u5ff5\u7ed3\u6784\u8bbe\u8ba1<\/p>\n

        \n
      • \u4ea7\u51fa<\/li>\n
      • ER\u6a21\u578b<\/strong><\/li>\n<\/ul>\n

        3\u3001\u903b\u8f91\u7ed3\u6784\u8bbe\u8ba1<\/p>\n

          \n
        • \u4ea7\u51fa<\/li>\n
        • \u5173\u7cfb\u6a21\u5f0f<\/li>\n<\/ul>\n

          4\u3001\u7269\u7406\u8bbe\u8ba1<\/p>\n

            \n
          • \u4ea7\u751f<\/li>\n
          • \u6570\u636e\u5e93\u548c\u8868\u3002<\/li>\n<\/ul>\n

            5\u3001\u56fe\u793a<\/p>\n

            \"image-20240219145536095\"<\/div><\/p>\n

            3\u3001E-R\u6a21\u578b<\/h2>\n

            1\u3001\u8bb2\u89e3\u56fe\u4f8b<\/h3>\n

            1\u3001\u65b9\u6846\uff1a\u5b9e\u4f53<\/p>\n

            2\u3001\u692d\u5706\uff1a\u5c5e\u6027<\/p>\n

            3\u3001\u83f1\u5f62\uff1a\u8054\u7cfb<\/p>\n

            4\u3001\u65b9\u6846\u4e2d\u6709\u4e24\u6761\u7ad6\u7ebf\uff1a\u5f31\u5b9e\u4f53<\/p>\n

            5\u3001\u4e00\u6761\u7ebf\u4e0a\u6709\u4e00\u4e2a\u5b9e\u5fc3\u5706\u70b9\uff1a\u7279\u6b8a\u5316<\/p>\n

            6\u3001\u5982\u56fe<\/p>\n

            \"image-20240219145914748\"<\/div><\/p>\n

            2\u3001\u8054\u7cfb<\/h3>\n

            1\u30011\u20141\u8054\u7cfb(1:1)<\/h4>\n

            1\u3001\u5982\u56fe\u6709\u8fd9\u6837\u7684\u4e00\u4e2a\u8054\u7cfb\u9700\u8981\u8f6c\u6362<\/p>\n

            \"image-20240219150521609\"<\/div><\/p>\n

            2\u3001\u91cd\u70b9\u662f1-1\u5173\u7cfb<\/p>\n

            3\u3001\u6211\u4eec\u8fd9\u91cc\u7684\u4efb\u804c\u6709\u4e09\u79cd\u65b9\u6cd5<\/p>\n

            4\u3001\u7b2c\u4e00\u79cd\uff08\u5c061:1\u8054\u7cfb\u8f6c\u6362\u4e3a\u4e00\u4e2a\u72ec\u7acb\u7684\u5173\u7cfb\uff09<\/p>\n

              \n
            • \u4e0e\u8be5\u8054\u7cfb\u76f8\u8fde\u7684\u5404\u5b9e\u4f53\u7684\u7801\u4ee5\u53ca\u8054\u7cfb\u672c\u8eab\u7684\u5c5e\u6027\u5747\u8f6c\u6362\u4e3a\u5173\u7cfb\u7684\u5c5e\u6027\uff0c\u4e14\u6bcf\u4e2a\u5b9e\u4f53\u7684\u7801\u5747\u662f\u8be5\u5173\u7cfb\u7684\u5019\u9009\u7801\u3002<\/strong><\/li>\n
            • \u5c31\u662f\u5355\u72ec\u5efa\u7acb\u4e00\u4e2a\u4efb\u804c\u8868\uff08\u4efb\u804c\u65f6\u95f4\uff0c\u59d3\u540d\uff0c\u6821\u540d\uff09\u3002\u6211\u4eec\u628a\u8054\u7cfb\u4e24\u7aef\u7684\u4e3b\u952e\u62ff\u8fc7\u6765\uff0c\u548c\u4efb\u804c\u5408\u5e76\u6210\u4e00\u5f20\u8868\u3002<\/li>\n<\/ul>\n

              5\u3001\u7b2c\u4e8c\u79cd\uff08\u5c061:1\u8054\u7cfb\u4e0e\u67d0\u4e00\u7aef\u5b9e\u4f53\u96c6\u6240\u5bf9\u5e94\u7684\u5173\u7cfb\u5408\u5e76\uff09<\/p>\n

                \n
              • \u5219\u9700\u8981\u5728\u88ab\u5408\u5e76\u5173\u7cfb\u4e2d\u589e\u52a0\u5c5e\u6027\uff0c\u5176\u65b0\u589e\u7684\u5c5e\u6027\u4e3a\u8054\u7cfb\u672c\u8eab\u7684\u5c5e\u6027\u548c\u4e0e\u8054\u7cfb\u76f8\u5173\u7684\u53e6\u4e00\u4e2a\u5b9e\u4f53\u96c6\u7684\u7801\u3002<\/li>\n
              • \u6211\u4eec\u628a\u4efb\u804c\u8868\u548c\u6821\u957f\u8868\u4e00\u8d77\u5408\u5e76,\u73b0\u5728\u6821\u957f\u8868\uff08\u59d3\u540d\uff0c\u6027\u522b\uff0c\u804c\u79f0\uff0c\u5e74\u9f84\uff0c\u4efb\u804c\u65f6\u95f4\uff0c\u5b66\u6821\uff09<\/li>\n<\/ul>\n

                6\u3001\u7b54\u6848<\/p>\n

                  \n
                • \n
                  \"image-20240219151106024\"<\/div>\n<\/li>\n<\/ul>\n

                  2\u30011\u2014\u591a\u8054\u7cfb(1:n)<\/h4>\n

                  0\u3001\u4f8b\u5b50<\/p>\n

                  \"image-20240219151548636\"<\/div><\/p>\n

                  1\u3001\u8fd9\u91cc\u6709\u4e24\u79cd\u65b9\u6cd5<\/p>\n

                  2\u3001\u7b2c\u4e00\u79cd<\/p>\n

                    \n
                  • \u4e00\u79cd\u65b9\u6cd5\u662f\u5c06\u8054\u7cfb\u8f6c\u6362\u4e3a\u4e00\u4e2a\u72ec\u7acb\u7684\u5173\u7cfb\uff0c\u5176\u5173\u7cfb\u7684\u5c5e\u6027\u7531\u4e0e\u8be5\u8054\u7cfb\u76f8\u8fde\u7684\u5404\u5b9e\u4f53\u96c6\u7684\u7801\u4ee5\u53ca\u8054\u7cfb\u672c\u8eab\u7684\u5c5e\u6027\u7ec4\u6210\uff0c\u800c\u8be5\u5173\u7cfb\u7684\u7801\u4e3an\u7aef\u5b9e\u4f53\u96c6\u7684\u7801\uff1b<\/li>\n
                  • \u5c31\u662f\u8bf4\uff0c\u5173\u7cfb\u81ea\u5df1\u5efa\u7acb\u4e00\u5f20\u8868\uff0c\u8868\u91cc\u5b58\u81ea\u5df1\u7684\u5c5e\u6027\uff0c\u548c\u5173\u7cfb\u4e24\u7aef\u7684\u4e3b\u952e<\/li>\n<\/ul>\n

                    3\u3001\u7b2c\u4e8c\u79cd<\/p>\n

                      \n
                    • \u53e6\u4e00\u79cd\u65b9\u6cd5\u662f\u5728n\u7aef\u5b9e\u4f53\u96c6\u4e2d\u589e\u52a0\u65b0\u5c5e\u6027\uff0c\u65b0\u5c5e\u6027\u7531\u8054\u7cfb\u5bf9\u5e94\u76841\u7aef\u5b9e\u4f53\u96c6\u7684\u7801\u548c\u8054\u7cfb\u81ea\u8eab\u7684\u5c5e\u6027\u6784\u6210\uff0c\u65b0\u589e\u5c5e\u6027\u540e\u539f\u5173\u7cfb\u7684\u7801\u4e0d\u53d8<\/li>\n
                    • \u5c31\u662f\u628a\u5173\u7cfb\u7684\u5c5e\u6027\u52a0\u5230\uff0cN\u90a3\u5934\u7684\u8868\u4e2d\u3002<\/li>\n<\/ul>\n

                      4\u3001\u7b54\u6848<\/p>\n

                      \"image-20240219151650089\"<\/div><\/p>\n

                      3\u3001\u591a\u2014\u591a\u7684\u8054\u7cfb\uff08n:m)<\/h4>\n

                      1\u3001\u8fd9\u91cc\u6709\u4e00\u79cd\u65b9\u6cd5<\/p>\n

                        \n
                      • \u4e0e\u8be5\u8054\u7cfb\u76f8\u8fde\u7684\u5404\u5b9e\u4f53\u96c6\u7684\u7801\u4ee5\u53ca\u8054\u7cfb\u672c\u8eab\u7684\u5c5e\u6027\u5747\u8f6c\u6362\u4e3a\u5173\u7cfb\u7684\u5c5e\u6027\uff0c\u65b0\u5173\u7cfb\u7684\u7801\u4e3a\u4e24\u4e2a\u76f8\u8fde\u5b9e\u4f53\u7801\u7684\u7ec4\u5408\uff08\u8be5\u7801\u4e3a\u591a\u5c5e\u6027\u6784\u6210\u7684\u7ec4\u5408\u7801\uff09<\/li>\n
                      • \u8bf4\u4eba\u8bdd\uff1a\u5c31\u662f\u628a\u8fd9\u4e2a\u5173\u7cfb\u5355\u72ec\u5efa\u4e00\u5f20\u8868\uff0c\u52a0\u4e0a\u81ea\u5df1\u7684\u5c5e\u6027\u548c\u5173\u7cfb\u4e24\u7aef\u7684\u4e3b\u952e\u3002<\/li>\n<\/ul>\n

                        2\u3001\u4f8b\u5b50<\/p>\n

                        \"image-20240219152147682\"<\/div><\/p>\n

                        3\u3001\u7b54\u6848<\/p>\n

                        \"image-20240219152202562\"<\/div><\/p>\n

                        4\u3001\u603b\u7ed3<\/h4>\n

                        1\u3001\u4e00\u4e2a\u5b9e\u4f53\u578b\u8f6c\u6362\u4e3a\u4e00\u4e2a\u5173\u7cfb\u6a21\u5f0f<\/p>\n

                        2\u3001\u8054\u7cfb\u8f6c\u5173\u7cfb\u6a21\u5f0f\uff1a<\/p>\n

                          \n
                        • 1:1\u8054\u7cfb\uff1a\u53ef\u5c06\u8054\u7cfb\u5408\u5e76\u81f3\u4efb\u610f\u4e00\u7aef\u7684\u5b9e\u4f53\u5173\u7cfb\u6a21\u5f0f\u4e2d<\/li>\n
                        • 1:n\u8054\u7cfb\uff1a\u53ef\u5c06\u8054\u7cfb\u5408\u5e76\u81f3n\u7aef\u5b9e\u4f53\u5173\u7cfb\u6a21\u5f0f\u4e2d<\/li>\n
                        • m:n\u8054\u7cfb\uff1a\u8054\u7cfb\u5fc5\u987b\u5355\u72ec\u8f6c\u6210\u5173\u7cfb\u6a21\u5f0f<\/li>\n<\/ul>\n

                          3\u3001\u4e09\u4e2a\u4ee5\u4e0a\u5b9e\u4f53\u95f4\u7684\u4e00\u4e2a\u591a\u5143\u8054\u7cfb<\/p>\n

                            \n
                          • \u4f8b\u5b50<\/li>\n
                          • \n
                            \"image-20240219152635681\"<\/div>\n<\/li>\n
                          • D(A,B,C)\u3002\u6240\u4ee5\u662f\u81f3\u5c114\u4e2a<\/li>\n<\/ul>\n

                            4\u3001\u5173\u7cfb\u4ee3\u6570<\/h2>\n

                            1\u3001\u5e76\uff08Union\uff09<\/h3>\n

                            1\u3001 \u5173\u7cfbR\u548cS\u6709\u76f8\u540c\u7684n\uff08n\u4e2a\u5c5e\u6027\uff09\uff0c\u5c5e\u6027\u90fd\u6765\u81ea\u540c\u4e00\u4e2a\u57df<\/p>\n

                            2\u3001R\u4e0eS\u7684\u5e76\u8fd0\u7b97\u8868\u793a\uff1aRUS<\/p>\n

                            3\u3001\u7ed3\u679c\uff1an\u76ee\u5173\u7cfb\uff0c\u7531\u5c5e\u4e8eR\u6216\u5c5e\u4e8eS\u7684\u5143\u7ec4\u7ec4\u6210\uff08\u628a\u4e0d\u76f8\u540c\u7684\u653e\u5728\u4e00\u8d77\uff0c\u76f8\u540c\u7684\u53ea\u7559\u4e00\u4e2a\uff09<\/p>\n

                            4\u3001\u8bf4\u4eba\u8bdd\uff1a\u5c31\u662f\u628aR\u3001S\u76f8\u540c\u7684\u53ea\u4fdd\u7559\u4e00\u4e2a\uff0c\u5176\u4ed6\u5168\u90e8\u5408\u5e76\u5c55\u51fa\u3002<\/strong><\/p>\n

                            4\u3001

                            \"image-20230818170212389\"<\/div><\/p>\n

                            2\u3001\u5dee\uff08except\uff09<\/h3>\n

                            1\u30011\u3001 \u5173\u7cfbR\u548cS\u6709\u76f8\u540c\u7684n\uff08n\u4e2a\u5c5e\u6027\uff09\uff0c\u5c5e\u6027\u90fd\u6765\u81ea\u540c\u4e00\u4e2a\u57df<\/p>\n

                            2\u3001R\u4e0eS\u7684\u539f\u9178\u8868\u793a\uff1aR-S<\/p>\n

                            3\u3001\u8fd0\u7b97\u7ed3\u679c\uff1an\u76ee\u5173\u7cfb\uff0c\u7531\u5c5e\u4e8eR\u800c\u4e0d\u5c5e\u4e8eS\u7684\u6240\u6709\u5143\u7ec4\u7ec4\u6210<\/p>\n

                            4\u3001\u8bf4\u4eba\u8bdd\uff1a\u5c31\u662fR-S\uff0cR\u6709\u7684\u800cS\u6ca1\u6709\u7684\uff0c\u4f5c\u4e3a\u7ed3\u679c\u3002<\/strong><\/p>\n

                            4\u3001\u4f8b\u5b50<\/p>\n

                            \"image-20230818170221284\"<\/div><\/p>\n

                            3\u3001\u4ea4\uff08intersection\uff09<\/h3>\n

                            1\u3001\u5173\u7cfbR\u548cS\u6709\u76f8\u540c\u7684n\uff08n\u4e2a\u5c5e\u6027\uff09\uff0c\u5c5e\u6027\u90fd\u6765\u81ea\u540c\u4e00\u4e2a\u57df<\/p>\n

                            2\u3001R\u4e0eS\u7684\u4ea4\u8fd0\u7b97\u8868\u793a\uff1aR \u2229 S<\/p>\n

                            3\u3001\u8fd0\u7b97\u7ed3\u679c\uff1an\u76ee\u5173\u7cfb\uff0c\u65e2\u5c5e\u4e8eR\u53c8\u5c5e\u4e8eS\u7684\u5143\u7ec4\u7ec4\u6210<\/p>\n

                            4\u3001\u8bf4\u5982\u8bdd\uff1a\u5c31\u662f\u628aR\u548cS\u4e2d\u76f8\u540c\u7684\u5143\u7ec4\u4f5c\u4e3a\u7ed3\u679c<\/strong><\/p>\n

                            4\u3001\u7b1b\u5361\u5c14\u79ef\uff08Cartesian Product\uff09<\/h3>\n

                            1\u3001\u662f\u5e7f\u4e49\u7684\u7b1b\u5361\u5c14\u79ef<\/p>\n

                            2\u3001R\uff1an\u76ee\u7684\u5173\u7cfb\uff08\u5217\uff09\uff0ck1\u4e2a\u5143\u7ec4\uff08\u884c\uff09<\/p>\n

                            3\u3001S\uff1am\u76ee\u5173\u7cfb\uff08\u5217\uff09\uff0ck2\u4e2a\u5143\u7ec4<\/p>\n

                            4\u3001R\u4e0eS\u7684\u7b1b\u5361\u5c14\u79ef\u8fd0\u7b97\u8868\u793a\uff1aR X S<\/p>\n

                            5\u3001\u8fd0\u7b97\u7ed3\u679c\uff1a\u884c\uff1ak1*k2\u4e2a\u5143\u7ec4\uff1b\u5217\uff1a(m+n)\u5217 \u5143\u7ec4\u7684\u96c6\u5408<\/p>\n

                            6\u3001\u5176\u4e2d\u5143\u7ec4\u7684\u524dn\u5217\u662f\u5173\u7cfbR\u7684\u4e00\u4e2a\u5143\u7ec4\uff0c\u540em\u5217\u662f\u5173\u7cfbS\u7684\u4e00\u4e2a\u5143\u7ec4<\/p>\n

                            7\u3001\u8bf4\u4eba\u8bdd\uff1a\u5c31\u662f\u628aR\u548cS\u7684\u6bcf\u4e00\u6761\u6570\u636e\u76f8\u4e58\u3002<\/strong><\/p>\n

                            7\u3001\u4f8b\u5b50<\/p>\n

                            \"image-20230818171703118\"<\/div><\/p>\n

                            5\u3001\u9009\u62e9<\/h3>\n

                            1\u3001\u7528\u03c3 xxx = yyy \u5c31\u662f\u4e86<\/p>\n

                            2\u3001\u770b\u56fe\u5c31\u61c2\u4e86\uff0c\u8fd9\u6709\u4e24\u4e2a\u5173\u7cfb\uff0cS1\uff0cS2<\/p>\n

                            \"image-20240219155041621\"<\/div><\/p>\n

                            2\u3001\u6c42S1\u5173\u7cfb\u4e2d\u7684Sno=3\u7684\u9009\u62e9<\/p>\n

                            \"image-20240219155118164\"<\/div><\/p>\n

                            6\u3001\u6295\u5f71<\/h3>\n

                            1\u3001\u7528\u03c0 xxx,xxx \u5c31\u53ef\u4ee5\u5c55\u793a<\/p>\n

                            2\u3001\u5982\u56fe\u8fd8\u662f\u4ee5\u4e0a\u5173\u7cfb\u8868<\/p>\n

                            3\u3001\u6c42\u03c0 sno,sname\u7684\u6295\u5f71<\/p>\n

                            \"image-20240219155255092\"<\/div><\/p>\n

                            7\u3001\u81ea\u7136\u8fde\u63a5<\/h3>\n

                            1\u3001\u81ea\u7136\u8fde\u63a5\u7684\u7b26\u53f7\uff1a\u25b7\u25c1<\/p>\n

                            2\u3001\u5c31\u76f8\u5f53\u4e8e\u8fdb\u884c\u4e86\uff1a\u5148\u7b1b\u5361\u5c14\u79ef\uff0c\u518d\u505a\u9009\u62e9\uff0c\u518d\u505a\u6295\u5f71<\/p>\n

                            3\u3001\u8fd9\u91cc\u628a\u4e24\u4e2a\u5173\u7cfb\u76f8\u540c\u7684\u5c5e\u6027\uff0c\u53ea\u4fdd\u7559\u4e00\u4e2a\u3002\u7136\u540e\u8fdb\u884c\u6295\u5f71<\/p>\n

                            4\u3001\u5982\u56fe\u4f8b\u5b50<\/p>\n

                              \n
                            • \u4ee5\u4e0b\u4e24\u4e2a\u5173\u7cfb<\/li>\n
                            • \n
                              \"image-20240219155540372\"<\/div>\n<\/li>\n
                            • \u7b54\u6848\uff1a<\/li>\n
                            • \n
                              \"image-20240219155557915\"<\/div>\n<\/li>\n<\/ul>\n

                              5\u3001\u89c4\u8303\u5316<\/h2>\n

                              1\u3001\u51fd\u6570\u4f9d\u8d56<\/h3>\n

                              1\u3001\u5b9a\u4e49\u4e00<\/h4>\n

                              1\u3001\u8bbeR(U\uff09\u662f\u5c5e\u6027\u96c6U\u4e0a\u7684\u5173\u7cfb\u6a21\u5f0f\uff0cX\u3001Y\u662fU\u7684\u5b50\u96c6\u3002\u5bf9\u4e8eR(U)\u7684\u4efb\u610f\u4e00\u4e2a\u53ef\u80fd\u7684\u5173\u7cfbr\uff0cr\u4e2d\u4e0d\u53ef\u80fd\u5b58\u5728\u4e24\u4e2a\u5143\u7ec4\u4ee5\u4e0a\u7684\u5c5e\u6027\u503c\u76f8\u5bf9\uff0c\u800c\u5728Y\u4e0a\u7684\u5c5e\u6027\u503c\u4e0d\u7b49\u3002\u79f0\u4e3a\u201cX\u51fd\u6570\u786e\u5b9aY"\u3001\u6216\u8005\u201dY\u51fd\u6570\u4f9d\u8d56\u4e8eX<\/strong>"\u3002\u8bb0\u4f5cX->Y\uff08\u5c31\u662f\u76f8\u5f53\u4e8e\u4e24\u884c\u4e2d\u7684\uff0c\u4e00\u4e2a\u552f\u4e00id\u53ea\u80fd\u5bf9\u5e94\u4e00\u4e2a\u540d\u5b57\uff0c\u4e0d\u80fd\u51fa\u73b0\u4e24\u4e2a\u540d\u5b57\uff0c\u8fd9\u4e2a\u5c31\u662f\u4f9d\u8d56\uff09<\/p>\n

                              2\u3001\u6709\u4e3b\u7801\u6216\u5173\u952e\u5b57\u5173\u7cfb\uff1a\u80af\u5b9a\u6709\u51fd\u6570\u4f9d\u8d56<\/p>\n

                              2\u3001\u5b9a\u4e49\u4e8c\uff08\u90e8\u5206\u3001\u5b8c\u5168\u51fd\u6570\u4f9d\u8d56\uff09<\/h4>\n

                              1\u3001\u3001\u5728R(U)\u4e2d\uff0c\u5982\u679cX->Y\uff0c\u5e76\u4e14X\u4e2d\u7684\u4efb\u4f55\u4e00\u4e2a\u771f\u5b50\u96c6\u90fd\u63a8\u4e0d\u51faY\uff08\u5fc5\u987b\u8981\u5168\u90e8X\u7684\u771f\u5b50\u96c6\u624d\u80fd\u63a8\u51faY\uff09\uff0c\u5219\u79f0\u4e3aY\u5bf9X\u5b8c\u5168\u4f9d\u8d56\u5173\u7cfb\uff0c<\/strong><\/p>\n

                                \n
                              • \n

                                \u8bf4\u4eba\u8bdd\u5c31\u662fX\u91cc\u9762\u6240\u6709\u4e00\u8d77\uff0c\u624d\u80fd\u63a8\u51fa\u6765Y\uff0c\u5176\u4e2d\u4efb\u4f55\u4e00\u4e2a\u5355\u72ec\u90fd\u63a8\u4e0d\u51fa\u6765\uff0c\u624d\u662f\u5b8c\u5168\u51fd\u6570\u4f9d\u8d56\u3002<\/p>\n<\/li>\n

                              • \n

                                \u8bb0\u4f5c:

                                \"image-20230912215117930\"<\/div><\/p>\n<\/li>\n<\/ul>\n

                                2\u3001\u5982\u679cX->Y\uff0c\u4f46Y\u4e0d\u5b8c\u5168\u51fd\u6570\u4f9d\u8d56\u4e8eX\uff08\u5c31\u662f\u53ea\u8981X\u4e2d\u6709\u4e00\u4e2a\u6216\u51e0\u4e2a\u548cY\u6709\u4f9d\u8d56\uff0c\u5c31\u4e0d\u662f\u5b8c\u5168\u51fd\u6570\u4f9d\u8d56)\uff0c\u5219\u79f0\u4e3aY\u5bf9X\u7684\u90e8\u5206\u51fd\u6570\u4f9d\u8d56<\/p>\n

                                  \n
                                • \n

                                  \u5c31\u662f\u53ea\u8981X\u4e2d\u6709\u4e00\u4e2a\u6216\u51e0\u4e2a\u548cY\u6709\u4f9d\u8d56\uff0c\u5c31\u4e0d\u662f\u5b8c\u5168\u51fd\u6570\u4f9d\u8d56<\/p>\n<\/li>\n

                                • \n

                                  \u8bb0\u4f5c\uff1a

                                  \"image-20230912220016413\"<\/div><\/p>\n<\/li>\n<\/ul>\n

                                  3\u3001\u5b9a\u4e49\u4e09\uff08\u4f20\u9012\u51fd\u6570\u4f9d\u8d56\uff09<\/h4>\n

                                  1\u3001\u5c31\u662f\u8bf4X\u80fd\u63a8\u51faY\uff0cY\u4e0d\u80fd\u63a8\u51faX<\/strong>\uff0c\u4f46\u662fY\u53ef\u4ee5\u63a8\u51faZ\u3002\u6240\u4ee5Z\u5bf9X\u4f20\u9012\u51fd\u6570\u4f9d\u8d56<\/p>\n

                                  2\u3001\u5982\u679cX\u80fd\u63a8\u51faY\uff0cY\u4e5f\u80fd\u63a8\u51faX\uff0c\u90a3\u4e48Z\u76f4\u63a5\u4f9d\u8d56\u4e8eX\uff0c\u5c31\u4e0d\u662f\u4f20\u9012\u51fd\u6570\u4e86<\/p>\n

                                  3\u3001\u4f8b\u5b50

                                  \"image-20230912221359522\"<\/div><\/p>\n

                                  2\u3001\u952e<\/h3>\n

                                  1\u3001\u5019\u9009\u952e\uff08\u5019\u9009\u7801\uff09\uff1a\u53ea\u8981\u4e00\u4e2a\u5173\u7cfb\u4e2d\uff0c\u4e00\u4e2a\u5c5e\u6027\u80fd\u552f\u4e00\u786e\u5b9a\u4e00\u4e2a\u503c\u6216\u4e00\u884c\uff0c\u5c31\u90fd\u53eb\u5019\u9009\u7801<\/p>\n

                                  2\u3001\u4e3b\u952e\uff08\u4e3b\u7801\uff09\uff1a\u4efb\u9009\u4e00\u4e2a\u5019\u9009\u952e\uff0c\u5c31\u53ef\u4ee5\u4f5c\u4e3a\u4e3b\u7801<\/p>\n

                                  3\u3001\u5916\u952e\uff08\u5916\u7801\uff09\uff1a\u5176\u4ed6\u5173\u7cfb\u7684\u4e3b\u952e\uff08\u4e3b\u7801\uff09<\/p>\n

                                  1\u3001\u56fe\u793a\u6cd5\u6c42\u5019\u9009\u952e<\/h4>\n

                                  1\u3001\u5c06\u5173\u7cfb\u7684\u51fd\u6570\u4f9d\u8d56\u5173\u7cfb\uff0c\u7528\u201c\u6709\u5411\u56fe\u201d\u7684\u65b9\u5f0f\u8fdb\u884c\u8868\u793a\u3002<\/p>\n

                                  2\u3001\u627e\u51fa\u5165\u5ea6\u4e3a0\uff0c\uff08\u5c31\u662f\u53ea\u6709\u51fa\uff0c\u6ca1\u6709\u8fdb\uff09\uff0c\u5e76\u4ee5\u8be5\u5c5e\u6027\u96c6\u5408\u4e3a\u8d77\u70b9\uff0c\u5c1d\u8bd5\u904d\u5386\u6709\u5411\u56fe\uff0c\u82e5\u80fd\u6b63\u5e38\u904d\u5386\u56fe\u4e2d\u6240\u6709\u7ed3\u70b9\uff0c\u5219\u8be5\u5c5e\u6027\u96c6\uff0c\u5c31\u662f\u5173\u7cfb\u6a21\u5f0f\u7684\u5019\u9009\u952e<\/p>\n

                                  3\u3001\u82e5\u5165\u5ea6\u4e3a0\u7684\u5c5e\u6027\u96c6\u4e0d\u80fd\u904d\u5386\u56fe\u4e2d\u6240\u6709\u8282\u70b9\uff0c\u5219\u9700\u8981\u5c1d\u8bd5\u6027\u7684\u5c06\u4e00\u4e9b\u4e2d\u95f4\u8282\u70b9\uff08\u65e2\u6709\u5165\u5ea6\u53c8\u6709\u51fa\u5ea6\u7684\u7ed3\u70b9\uff09\u5e76\u5165\uff0c\u5165\u5ea6\u4e3a0\u7684\u5c5e\u6027\u96c6\u5316\u603b\uff0c\u76f4\u81f3\u8be5\u96c6\u5408\u80fd\u904d\u5386\u5230\u6240\u6709\u8282\u70b9\uff0c\u96c6\u5408\u4e3a\u5019\u9009\u7801\u3002<\/strong><\/p>\n

                                  4\u3001\u4f8b\u5b50<\/p>\n

                                  \"image-20240219165107197\"<\/div><\/p>\n

                                  3\u3001\u4e3b\u5c5e\u6027\u548c\u975e\u4e3b\u5c5e\u6027<\/h3>\n

                                  1\u3001\u7ec4\u6210\u5019\u9009\u7801\u7684\u5c5e\u6027\u5c31\u662f\u4e3b\u5c5e\u6027\uff0c\u5176\u4ed6\u7684\u5c31\u662f\u975e\u4e3b\u5c5e\u6027<\/p>\n

                                  4\u3001\u8303\u5f0f<\/h3>\n

                                  1\u3001\u7b2c\u4e00\u8303\u5f0f<\/h4>\n

                                  1\u3001\u4e00\u4e2a\u5173\u7cfb\u4e2d\uff0c\u4e0d\u53ef\u518d\u5206\u9694\u7684\u72ec\u7acb\u7684\u5355\u5143\u683c\u6570\u636e\u5c31\u662f\u7b2c\u4e00\u8303\u5f0f<\/p>\n

                                  2\u3001\u8bf4\u4eba\u8bdd\uff1a\u5c31\u662f\u6bcf\u4e2a\u5c5e\u6027\u90fd\u4e0d\u53ef\u518d\u5206\u7684\u6570\u636e\u9879\uff0c\u5c31\u662f\u7b2c\u4e00\u8303\u5f0f<\/p>\n

                                  2\u3001\u7b2c\u4e8c\u8303\u5f0f<\/h4>\n

                                  1\u3001\u82e5\u67d0\u5173\u7cfbR\u5c5e\u4e8e\u7b2c\u4e00\u8303\u5f0f\uff0c\u4e14\u6bcf\u4e00\u4e2a\u975e\u4e3b\u5c5e\u6027\u5b8c\u5168\u51fd\u6570\u4f9d\u8d56\u4e8e\u4efb\u4f55\u4e00\u4e2a\u5019\u9009\u7801\uff0c\u5219\u5173\u7cfbR\u5c5e\u4e8e\u7b2c\u4e8c\u8303\u5f0f<\/p>\n

                                  2\u3001\u7b2c\u4e8c\u8303\u5f0f\u662f\u6307\u6bcf\u4e2a\u8868\u5fc5\u987b\u6709\u4e00\u4e2a\uff08\u6709\u4e14\u4ec5\u6709\u4e00\u4e2a\uff09\u6570\u636e\u9879\u4f5c\u4e3a\u5173\u952e\u5b57\u6216\u4e3b\u952e\uff08primary key\uff09\uff0c\u5176\u4ed6\u6570\u636e\u9879\u4e0e\u5173\u952e\u5b57\u6216\u8005\u4e3b\u952e\u4e00\u4e00\u5bf9\u5e94\uff0c\u5373\u5176\u4ed6\u6570\u636e\u9879\u5b8c\u5168\u4f9d\u8d56\u4e8e\u5173\u952e\u5b57\u6216\u4e3b\u952e\u3002\u7531\u6b64\u53ef\u77e5\u5355\u4e3b\u5c5e\u6027\u7684\u5173\u7cfb\u5747\u5c5e\u4e8e\u7b2c\u4e8c\u8303\u5f0f<\/p>\n

                                  3\u3001\u5c31\u662f\u6ca1\u6709\u90e8\u5206\u51fd\u6570\u4f9d\u8d56<\/p>\n

                                  4\u3001\u4f8b\u5b50\uff08\u7406\u89e3\uff09<\/p>\n

                                    \n
                                  • SC\u8868\uff08\u5b66\u53f7\uff0c\u8bfe\u7a0b\u53f7<\/strong>\uff0c\u6210\u7ee9\uff0c\u5b66\u5206\uff09 \/\/ \u7740\u91cd\u7684\u662f\u5019\u9009\u7801<\/li>\n
                                  • \u5176\u4e2d\uff08\u5b66\u53f7\uff0c\u8bfe\u7a0b\u53f7\uff09\u2014>\u6210\u7ee9\u3002\u8fd9\u4e2a\u6ca1\u6709\u90e8\u5206\u51fd\u6570\u4f9d\u8d56\uff0c\u6240\u4ee5\u662f\u7b2c\u4e8c\u8303\u5f0f<\/li>\n
                                  • \u4f46\u662f\uff1a\uff08\u5b66\u53f7\uff0c\u8bfe\u7a0b\u53f7\uff09\u2014>\u6210\u7ee9\uff0c\u8bfe\u7a0b\u53f7\u2014>\u5b66\u5206\u3002\u8fd9\u4e2a\u5c31\u6709\u90e8\u5206\u51fd\u6570\u4f9d\u8d56\u4e86\uff0c\u5b66\u5206\u6ca1\u6709\u5b8c\u5168\u51fd\u6570\u4f9d\u8d56\u4e8e\u5b66\u53f7\u8fd9\u4e2a\u5019\u9009\u7801<\/li>\n
                                  • \u6211\u4eec\u53ef\u4ee5\u4fee\u6539\u4e24\u5f20\u8868\uff0c\u53ea\u80fd\u62c6\u554a<\/li>\n
                                  • (\u5b66\u53f7\uff0c\u8bfe\u7a0b\u53f7\uff0c\u6210\u7ee9)\uff0c\uff08\u8bfe\u7a0b\u53f7\uff0c\u5b66\u5206\uff09<\/li>\n<\/ul>\n

                                    5\u3001\u5982\u679c\u5728\u7b2c\u4e8c\u8303\u5f0f\u5c31\u89e3\u51b3\u4e86<\/p>\n

                                      \n
                                    • \u63d2\u5165\u5f02\u5e38<\/li>\n
                                    • \u4fee\u6539\u5f02\u5e38<\/li>\n
                                    • \u5220\u9664\u5f02\u5e38<\/li>\n<\/ul>\n

                                      3\u3001\u7b2c\u4e09\u8303\u5f0f<\/h4>\n

                                      1\u3001\u6ee1\u8db3\u7b2c\u4e8c\u8303\u5f0f\uff0c\u800c\u4e14\u6ca1\u6709\u4f20\u9012\u51fd\u6570\u4f9d\u8d56\u5019\u9009\u7801\u3002<\/p>\n

                                      4\u3001BC\u8303\u5f0f<\/h4>\n

                                      1\u3001\u8bbe\u5173\u7cfb\u6a21\u5f0fR<U,F>\u22081NF\uff0c\u82e5X\u63a8\u51faY\uff0cY\u4e0d\u5c5e\u4e8eX\u65f6\uff0cX\u5fc5\u987b\u6709\u4e2a\u4e3b\u7801\uff0c\u5219\u8868\u793aR<U,F>\u2208BCNF<\/p>\n

                                      2\u3001\u6362\u53e5\u8bdd\u8bf4\uff0c\u5c31\u662f\u5728\u5173\u7cfb\u6a21\u5f0fR<U,F>\u4e2d\uff0c\u5982\u679c\u6bcf\u4e00\u4e2a\u51b3\u5b9a\u5c5e\u6027\u96c6\u90fd\u5305\u542b\u5019\u9009\u7801\uff0c\u5219R\u5c5e\u4e8eBCNF<\/p>\n

                                      5\u3001\u8303\u5f0f\u603b\u7ed3<\/h4>\n

                                      \"image-20240219194406712\"<\/div><\/p>\n

                                      5\u3001\u6a21\u5f0f\u5206\u89e3<\/h3>\n

                                      1\u3001\u4fdd\u6301\u51fd\u6570\u4f9d\u8d56\u5206\u89e3<\/h4>\n

                                      1\u3001\u6982\u5ff5\uff1a<\/p>\n

                                        \n
                                      • \u8bbe\u6570\u636e\u5e93\u6a21\u5f0f\u03c1={R1\uff0cR2\uff0c\u2026\uff0cRk}\u662f\u5173\u7cfb\u6a21\u5f0fR\u7684\u4e00\u4e2a\u5206\u89e3\uff0cF\u662fR\u4e0a\u7684\u51fd\u6570\u4f9d\u8d56\u96c6\uff0c\u03c1\u4e2d\u6bcf\u4e2a\u6a21\u5f0fRi\u4e0a\u7684FD\u96c6\u662fFi\u3002<\/li>\n
                                      • \u5982\u679c{F1\uff0cF2\uff0c\u2026\uff0cFk}\u4e0eF\u662f\u7b49\u4ef7\u7684\uff08\u5373\u76f8\u4e92\u903b\u8f91\u8574\u6db5\uff09\uff0c\u90a3\u4e48\u79f0\u5206\u89e3\u03c1\u4fdd\u6301FD\u3002<\/li>\n<\/ul>\n

                                        2\u3001\u4f8b\u5b50<\/p>\n

                                          \n
                                        • \n

                                          \u4f8b1<\/strong>\uff1a\u6709\u5173\u7cfb\u6a21\u5f0fR\uff08A\uff0cB\uff0cC\uff09\uff0cF={A\u2192B\uff0cB\u2192C}\uff0c\u5c06\u5176\u62c6\u5206\u4e3a\uff1aR1{A\uff0cB}\uff0cR2{B\uff0cC}\uff0c\u662f\u5426\u4fdd\u6301\u51fd\u6570\u4f9d\u8d56\u3002<\/p>\n<\/li>\n

                                        • \n

                                          R1{A\uff0cB}\uff0cF1{A\u2192B}<\/p>\n<\/li>\n

                                        • \n

                                          R2{B\uff0cC}\uff0cF2{B\u2192C}<\/p>\n<\/li>\n

                                        • \n

                                          F1\uff0cF2\u4e0eF\u662f\u7b49\u4ef7\u7684\uff0c\u6240\u4ee5\u4fdd\u6301\u51fd\u6570\u4f9d\u8d56\u5206\u89e3\u3002<\/p>\n<\/li>\n<\/ul>\n

                                          2\u3001\u65e0\u635f\u5206\u89e3<\/h4>\n

                                          1\u3001\u6709\u635f\uff1a\u4e0d\u80fd\u8fd8\u539f<\/p>\n

                                          2\u3001\u65e0\u635f\uff1a\u53ef\u4ee5\u8fd8\u539f<\/p>\n

                                          3\u3001\u65e0\u635f\u8054\u63a5<\/p>\n

                                            \n
                                          • \u6307\u5c06\u4e00\u4e2a\u5173\u7cfb\u6a21\u5f0f\u5206\u89e3\u6210\u82e5\u5e72\u5173\u7cfb\u6a21\u5f0f\u540e\uff0c\u901a\u8fc7\u81ea\u7136\u8054\u63a5\u548c\u6295\u5f71\u7b49\u8fd0\u7b97\u4ecd\u80fd\u8fd8\u539f\u5230\u539f\u6765\u7684\u5173\u7cfb\u6a21\u5f0f<\/li>\n<\/ul>\n

                                            3\u3001\u65e0\u635f\u5206\u89e3\u2014\u2014\u516c\u5f0f\u6cd5\uff08\u53ea\u80fd\u9002\u7528\u4e8e\u4e24\u4e2a\uff09<\/h4>\n

                                            1\u3001\u7406\u89e3<\/p>\n

                                            \"image-20240219203518864\"<\/div><\/p>\n

                                            2\u3001\u4f8b\u5b50

                                            \"image-20240219203534397\"<\/div><\/p>\n

                                            3\u3001\u7b54\u6848\uff1a\u662f\u65e0\u635f\u5206\u89e3<\/p>\n

                                              \n
                                            • R1\u2229R2 = A<\/li>\n
                                            • R1 - R2 = B <\/li>\n
                                            • R2 - R1 = C<\/li>\n
                                            • \u53c8\u56e0\u4e3aA\u2014>B\uff0c\u6240\u4ee5\u662f\u65e0\u635f\u5206\u89e3<\/li>\n<\/ul>\n

                                              4\u3001\u65e0\u635f\u5206\u89e3\u2014\u8868\u683c\u6cd5<\/h4>\n

                                              6\u3001SQL\u8bed\u53e5<\/h2>\n

                                              1\u3001\u5efa\u8868<\/h3>\n

                                              1\u3001\u8bed\u53e5<\/p>\n

                                                \n
                                              • creat table <\u8868\u660e><\/li>\n<\/ul>\n

                                                2\u3001\u5b8c\u6574\u683c\u5f0f<\/p>\n

                                                \"image-20240219215533944\"<\/div><\/p>\n

                                                3\u3001\u4f8b\u5b50<\/p>\n

                                                \"image-20240219215839942\"<\/div><\/p>\n

                                                2\u3001\u4fee\u6539\u4e0e\u5220\u9664\u8868<\/h3>\n

                                                1\u3001

                                                \"image-20240219215948157\"<\/div><\/p>\n

                                                3\u3001\u67e5\u8be2<\/h3>\n

                                                \"image-20240219220014290\"<\/div><\/p>\n

                                                4\u3001\u64cd\u4f5c\u603b\u548c<\/h3>\n

                                                \"image-20240219220224208\"<\/div><\/p>\n

                                                7\u3001\u5e76\u53d1\u63a7\u5236<\/h2>\n

                                                1\u3001\u4e8b\u52a1<\/h3>\n

                                                1\u3001\u539f\u5b50\u6027<\/p>\n

                                                2\u3001\u4e00\u81f4\u6027<\/p>\n

                                                3\u3001\u9694\u79bb\u6027<\/p>\n

                                                4\u3001\u6301\u7eed\u6027<\/p>\n

                                                2\u3001\u5e76\u53d1\u4ea7\u751f\u7684\u95ee\u9898<\/h3>\n

                                                1\u3001\u4e22\u5931\u66f4\u65b0<\/p>\n

                                                2\u3001\u4e0d\u53ef\u91cd\u590d\u8bfb\u95ee\u9898<\/p>\n

                                                3\u3001\u8bfb\u201c\u810f\u201d\u6570\u636e<\/p>\n

                                                4\u3001\u56fe\u793a<\/p>\n

                                                \"image-20240219222114735\"<\/div><\/p>\n

                                                3\u3001\u89e3\u51b3\u65b9\u6cd5<\/h3>\n

                                                1\u3001\u5c01\u9501\u534f\u8bae<\/p>\n

                                                  \n
                                                • S\u5c01\u9501\uff08\u5171\u4eab\u9501\uff09<\/li>\n
                                                • X\u5c01\u9501\uff08\u6392\u5b83\u9501\uff09<\/li>\n
                                                • \u4e24\u6bb5\u9501\u534f\u8bae<\/li>\n<\/ul>\n

                                                  2\u3001\u6b7b\u9501<\/p>\n

                                                    \n
                                                  • \u9884\u9632\u6b7b\u9501<\/li>\n
                                                  • \u6b7b\u9501\u7684\u89e3\u9664<\/li>\n<\/ul>\n

                                                    8\u3001\u6570\u636e\u5e93\u5b8c\u6574\u6027\u7ea6\u675f<\/h2>\n

                                                    1\u3001\u5b9e\u4f53\u5b8c\u6574\u6027\u7ea6\u675f<\/h3>\n

                                                    1\u3001\u4e3b\u952e<\/p>\n

                                                      \n
                                                    • \u975e\u7a7a<\/li>\n
                                                    • \u552f\u4e00<\/li>\n<\/ul>\n

                                                      2\u3001\u4e3b\u7801\u662f\u5426\u552f\u4e00\uff0c\u4e0d\u552f\u4e00\u5c31\u9519\u8bef\u6216\u62d2\u7edd<\/p>\n

                                                      3\u3001\u4e3b\u7801\u7684\u5c5e\u6027\u503c\uff0c\u662f\u5426\u4e3a\u7a7a\uff0c\u6709\u5c31\u76f4\u63a5\u62d2\u7edd\u6216\u4fee\u6539\u6389<\/p>\n

                                                      2\u3001\u53c2\u7167\u5b8c\u6574\u6027\u7ea6\u675f<\/h3>\n

                                                      1\u3001FOREIGN KEY \u5b9a\u4e49<\/p>\n

                                                      2\u3001\u7528REFERENCES\u77ed\u8bed\u77e5\u540d\u8fd9\u4e9b\u5916\u7801\u662f\u53c2\u7167\u54ea\u4e9b\u8868\u7684\u4e3b\u7801<\/p>\n

                                                      3\u3001\u4f8b\u5b50<\/p>\n

                                                      \"image-20230906224427609\"<\/div><\/p>\n

                                                      3\u3001\u7528\u6237\u81ea\u5b9a\u4e49\u5b8c\u6574\u6027\u7ea6\u675f<\/h3>\n

                                                      1\u3001\u5217\u503c\u975e\u7a7a\uff08NOT NULL)\u3001\u552f\u4e00\uff08UNIQUE\uff09\u3001\u662f\u5426\u6ee1\u8db3\u4e00\u4e2a\u8868\u8fbe\u5f0f\uff08CHECK\uff09<\/p>\n

                                                      2\u3001\u4f8b\u5b50<\/p>\n

                                                      \"image-20230906232448056\"<\/div><\/p>\n

                                                      4\u3001\u89e6\u53d1\u5668<\/h3>\n

                                                      1\u3001\u4ecb\u7ecd<\/h4>\n

                                                      1\u3001\u89e6\u53d1\u5668\u662f\u7528\u6237\u5b9a\u4e49\u5728\u5173\u7cfb\u8868\u4e0a\u7684\u4e00\u7c7b\u7531\u4e8b\u4ef6\u9a71\u52a8\u7684\u7279\u6b8a\u8fc7\u7a0b<\/p>\n

                                                      2\u3001\u8bf4\u660e<\/h4>\n

                                                      1\u3001\u89e6\u53d1\u5668\u4fdd\u5b58\u5728\u6570\u636e\u5e93\u670d\u52a1\u5668\u4e2d<\/p>\n

                                                      2\u3001\u4efb\u4f55\u7528\u6237\u7684\u589e\u5220\u6539\u64cd\u4f5c\uff0c\u7531\u670d\u52a1\u5668\u81ea\u52a8\u6fc0\u6d3b\u89e6\u53d1\u5668<\/p>\n

                                                      3\u3001\u89e6\u53d1\u5668\u53ef\u4ee5\u5b9e\u65bd\u66f4\u4e3a\u590d\u6742\u7684\u68c0\u67e5\u548c\u64cd\u4f5c\uff0c\u5177\u6709\u66f4\u7cbe\u7ec6\u548c\u5f3a\u5927\u7684\u6570\u636e\u63a7\u5236\u80fd\u529b<\/p>\n

                                                      3\u3001\u5b9a\u4e49\u89e6\u53d1\u5668<\/h4>\n

                                                      1\u3001\u89e6\u53d1\u5668\u53c8\u53eb\u4e8b\u4ef6-\u6761\u4ef6-\u52a8\u4f5c<\/p>\n

                                                      2\u3001\u683c\u5f0f<\/p>\n

                                                      CREATE TRIGGER <\u89e6\u53d1\u5668\u540d\u79f0>\n{BEFORE |AFTER} <\u89e6\u53d1\u4e8b\u4ef6> ON <\u8868\u540d>\nREFERENCING NEW | OLD ROW AS <\u53d8\u91cf>\nFROM EACH {ROW | STATEMENT}\n[WHEN <\u89e6\u53d1\u6761\u4ef6>] <\u89e6\u53d1\u52a8\u4f5c\u63d0><\/code><\/pre>\n
                                                      4\u3001\u5b9a\u4e49\u89e6\u53d1\u5668\u8bed\u6cd5\u8bf4\u660e<\/h4>\n
                                                      1\u3001\u5fc5\u987b\u662f\u8868\u7684\u62e5\u6709\u8005<\/h5>\n
                                                      2\u3001\u89e6\u53d1\u5668\u540d<\/h5>\n
                                                      1\u3001\u89e6\u53d1\u5668\u53ef\u4ee5\u5305\u542b\u6a21\u5f0f\u540d\uff0c\u4e5f\u53ef\u4ee5\u4e0d\u5305\u542b<\/p>\n
                                                      2\u3001\u5728\u540c\u4e00\u6a21\u5f0f\u4e0b\u89e6\u53d1\u5668\u5fc5\u987b\u552f\u4e00<\/p>\n
                                                      3\u3001\u8868\u540d<\/h5>\n
                                                      1\u3001\u89e6\u53d1\u5668\u53ea\u80fd\u5b9a\u4e49\u5728\u57fa\u672c\u8868\u4e0a\uff0c\u4e0d\u80fd\u5b9a\u4e49\u5728\u89c6\u56fe<\/p>\n
                                                      2\u3001\u5982\u679c\u57fa\u672c\u8868\u53d1\u751f\u53d8\u5316\uff0c\u5219\u5bf9\u5e94\u7684\u89e6\u53d1\u5668\u4e5f\u4f1a\u88ab\u6fc0\u6d3b<\/p>\n
                                                      4\u3001\u4e8b\u4ef6\u89e6\u53d1<\/h5>\n
                                                      1\u3001insert\/delete\/update\u8fd9\u51e0\u4e2a\u4e8b\u4ef6\u7ec4\u5408<\/p>\n
                                                      2\u3001update of<\u89e6\u53d1\u5217\uff0c\u2026>\uff0c\u5373\u8fdb\u4e00\u6b65\u77e5\u660e\u4fee\u6539\u54ea\u4e9b\u5217\u65f6\u673a\u4f1a\u89e6\u53d1\u5668<\/p>\n
                                                      3\u3001AFTER\uff1a\u4e8b\u4ef6\u5b8c\u6210\u540e\u624d\u6fc0\u6d3b\u89e6\u53d1\u5668<\/p>\n
                                                      4\u3001BEFORE\uff1a\u65f6\u95f4\u89e6\u53d1\u524d\uff0c\u6fc0\u6d3b\u89e6\u53d1\u5668<\/p>\n
                                                      5\u3001\u89e6\u53d1\u5668\u7c7b\u578b<\/h5>\n
                                                      1\u3001\u884c\u7ea7\u89e6\u53d1\u5668\uff08FOR EACH ROW)<\/p>\n
                                                      2\u3001\u8bed\u53e5\u7ea7\u89e6\u53d1\u5668\uff08FOR EACH STATEMENT)<\/p>\n
                                                      3\u3001\u4f8b\u5b50<\/p>\n
                                                      \"image-20230908102712104\"<\/div><\/p>\n
                                                      6\u3001\u89e6\u53d1\u6761\u4ef6<\/h5>\n
                                                      1\u3001\u89e6\u53d1\u4f53\u52a8\u4f5c\u4e3a\u771f\u65f6\uff0c\u89e6\u53d1\u52a8\u4f5c\u4f53\u624d\u6267\u884c\uff0c\u5426\u5219\u89e6\u53d1\u52a8\u4f5c\u4f53\u4e0d\u6267\u884c<\/p>\n
                                                      2\u3001\u5982\u679c\u6ca1\u6709WHEN\u89e6\u53d1\u6761\u4ef6\uff0c\u5219\u89e6\u53d1\u4f53\u52a8\u4f5c\u5728\u89e6\u53d1\u5668\u6fc0\u6d3b\u540e\u7acb\u5373\u6267\u884c<\/p>\n
                                                      7\u3001\u89e6\u53d1\u52a8\u4f5c\u4f53<\/h5>\n
                                                      1\u3001\u53ef\u4ee5\u662f\u533f\u540dPL\/SQL\u8fc7\u7a0b\u5757\uff0c\u4e5f\u53ef\u4ee5\u662f\u5bf9\u81ea\u5df1\u521b\u5efa\u5b58\u50a8\u8fc7\u7a0b\u7684\u8c03\u6574<\/p>\n
                                                      2\u3001\u5982\u679c\u662f\u884c\u7ea7\u89e6\u53d1\u5668\uff0c\u7528\u6237\u90fd\u53ef\u4ee5\u5728\u8fc7\u7a0b\u4f53\u4e2d\u4f7f\u7528new \u548cold\u5f15\u7528\u4e8b\u4ef6\u4e4b\u540e\u7684\u65b0\u503c\u548c\u4e8b\u4ef6\u4e4b\u524d\u7684\u65e7\u503c<\/p>\n
                                                      3\u3001\u5982\u679c\u8bed\u53e5\u89e6\u53d1\u5668\uff0c\u5219\u4e0d\u80fd\u5728\u89e6\u53d1\u52a8\u4f5c\u63d0\u5316\u603b\u4f7f\u7528new\u548cold<\/p>\n
                                                      4\u3001\u5982\u679c\u89e6\u53d1\u5668\u52a8\u4f5c\u4f53\u6267\u884c\u5931\u8d25\uff0c\u6fc0\u6d3b\u89e6\u53d1\u5668\u7684\u4e8b\u4ef6\u5c31\u4f1a\u7ec8\u6b62\u6267\u884c\uff0c\u89e6\u53d1\u5668\u7684\u76ee\u6807\u8868\u6216\u89e6\u53d1\u5668\u53ef\u80fd\u5f71\u54cd\u5176\u4ed6\u5bf9\u8c61\u4e0d\u53d1\u751f\u4efb\u4f55\u53d8\u5316<\/p>\n
                                                      5\u3001\u6ce8\u610f\uff1a\u4e0d\u540c\u7684RDBMS\u4ea7\u54c1\u89e6\u53d1\u5668\u8bed\u6cd5\u5404\u90e8\u76f8\u540c<\/strong><\/p>\n","protected":false},"excerpt":{"rendered":"
                                                      \u7b2c\u4e09\u7ae0\u3001\u6570\u636e\u5e93\u7cfb\u7edf\uff086\u5206~8\u5206\uff09 1\u3001\u4e3b\u8981\u8003\u8003\u5bdf 2\u3001ER\u6a21\u578b\u6709\u4e00\u4e2a\u5927\u9898\uff0c15\u5206\u3002\u4e0b\u5348\u8003 1\u3001\u4e09\u7ea7\u6a21\u5f0f-\u4e24\u5c42\u6620 […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[58],"tags":[],"class_list":["post-5989","post","type-post","status-publish","format-standard","hentry","category-58"],"_links":{"self":[{"href":"http:\/\/zyg.luchers.cn\/index.php\/wp-json\/wp\/v2\/posts\/5989","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/zyg.luchers.cn\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/zyg.luchers.cn\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/zyg.luchers.cn\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/zyg.luchers.cn\/index.php\/wp-json\/wp\/v2\/comments?post=5989"}],"version-history":[{"count":1,"href":"http:\/\/zyg.luchers.cn\/index.php\/wp-json\/wp\/v2\/posts\/5989\/revisions"}],"predecessor-version":[{"id":5990,"href":"http:\/\/zyg.luchers.cn\/index.php\/wp-json\/wp\/v2\/posts\/5989\/revisions\/5990"}],"wp:attachment":[{"href":"http:\/\/zyg.luchers.cn\/index.php\/wp-json\/wp\/v2\/media?parent=5989"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/zyg.luchers.cn\/index.php\/wp-json\/wp\/v2\/categories?post=5989"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/zyg.luchers.cn\/index.php\/wp-json\/wp\/v2\/tags?post=5989"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}