{"id":5693,"date":"2024-11-14T09:09:37","date_gmt":"2024-11-14T01:09:37","guid":{"rendered":"https:\/\/fwq.ai\/blog\/5693\/"},"modified":"2024-11-14T09:09:37","modified_gmt":"2024-11-14T01:09:37","slug":"sql%e5%a4%9a%e8%a1%a8%e8%81%94%e6%9f%a5%e6%80%8e%e4%b9%88%e5%86%99","status":"publish","type":"post","link":"https:\/\/fwq.ai\/blog\/5693\/","title":{"rendered":"sql\u591a\u8868\u8054\u67e5\u600e\u4e48\u5199"},"content":{"rendered":"

\n sql \u591a\u8868\u8054\u67e5\u5141\u8bb8\u60a8\u4ece\u591a\u4e2a\u8868\u4e2d\u63d0\u53d6\u76f8\u5173\u6570\u636e\u3002\u8bed\u6cd5\u4e3a\uff1aselect \u5217\u540d1, \u5217\u540d2, …from \u8868\u540d1join \u8868\u540d2 on \u8868\u540d1.\u5217\u540d = \u8868\u540d2.\u5217\u540d\u3002\u6b65\u9aa4\u5305\u62ec\uff1a\u786e\u5b9a\u9700\u8981\u5173\u8054\u7684\u8868\u3001\u786e\u5b9a\u8054\u63a5\u5b57\u6bb5\u3001\u4f7f\u7528 join \u8bed\u53e5\u5e76\u6307\u5b9a\u8054\u63a5\u7c7b\u578b\uff0c\u5305\u62ec\u5185\u8054\u63a5\u3001\u5de6\u5916\u8054\u63a5\u3001\u53f3\u5916\u8054\u63a5\u548c\u5168\u5916\u8054\u63a5\u3002\n<\/p><\/blockquote>\n

\"sql\u591a\u8868\u8054\u67e5\u600e\u4e48\u5199\u63d2\u56fe\"<\/p>\n

SQL \u591a\u8868\u8054\u67e5<\/strong><\/p>\n

\u5982\u4f55\u7f16\u5199 SQL \u591a\u8868\u8054\u67e5\uff1f<\/strong><\/p>\n

\u591a\u8868\u8054\u67e5\u5141\u8bb8\u60a8\u4ece\u591a\u4e2a\u8868\u4e2d\u63d0\u53d6\u76f8\u5173\u6570\u636e\u3002\u5728 SQL \u4e2d\uff0c\u4f7f\u7528 JOIN \u8bed\u53e5\u6267\u884c\u8054\u67e5\u3002<\/p>\n

\u8bed\u6cd5\uff1a<\/strong><\/p>\n

SELECT \u5217\u540d1, \u5217\u540d2, ...\nFROM \u8868\u540d1\nJOIN \u8868\u540d2 ON \u8868\u540d1.\u5217\u540d = \u8868\u540d2.\u5217\u540d\nJOIN \u8868\u540d3 ON \u8868\u540d2.\u5217\u540d = \u8868\u540d3.\u5217\u540d\n...<\/pre>\n
  \u767b\u5f55\u540e\u590d\u5236   <\/p>\n
\u6b65\u9aa4\uff1a<\/strong><\/p>\n
    \n
  1.  \u786e\u5b9a\u9700\u8981\u5173\u8054\u7684\u8868\uff1a<\/strong>\u786e\u5b9a\u5305\u542b\u6240\u9700\u6570\u636e\u7684\u8868\u3002<\/li>\n
  2.  \u786e\u5b9a\u8054\u63a5\u5b57\u6bb5\uff1a<\/strong>\u8bc6\u522b\u5404\u8868\u4e2d\u7528\u4e8e\u5173\u8054\u8bb0\u5f55\u7684\u901a\u7528\u5b57\u6bb5\u3002<\/li>\n
  3.  \u4f7f\u7528 JOIN \u8bed\u53e5\uff1a<\/strong>\u4f7f\u7528 JOIN \u8bed\u53e5\u5c06\u8868\u94fe\u63a5\u5728\u4e00\u8d77\uff0c\u6307\u5b9a\u8054\u63a5\u5b57\u6bb5\u3002<\/li>\n
  4.  \u6307\u5b9a\u8054\u63a5\u7c7b\u578b\uff1a<\/strong>\u9009\u62e9\u8054\u63a5\u7c7b\u578b\uff08\u5185\u8054\u63a5\u3001\u5de6\u5916\u8054\u63a5\u3001\u53f3\u5916\u8054\u63a5\u3001\u5168\u5916\u8054\u63a5\uff09\u3002<\/li>\n<\/ol>\n
    \u8054\u63a5\u7c7b\u578b\uff1a<\/strong><\/p>\n
      \n
    •  \u5185\u8054\u63a5\uff08INNER JOIN\uff09\uff1a<\/strong>\u4ec5\u8fd4\u56de\u51fa\u73b0\u5728\u6240\u6709\u5173\u8054\u8868\u4e2d\u7684\u8bb0\u5f55\u3002<\/li>\n
    •  \u5de6\u5916\u8054\u63a5\uff08LEFT OUTER JOIN\uff09\uff1a<\/strong>\u8fd4\u56de\u8868 1 \u4e2d\u7684\u6240\u6709\u8bb0\u5f55\uff0c\u5373\u4f7f\u8868 2 \u4e2d\u4e0d\u5b58\u5728\u5339\u914d\u8bb0\u5f55\u3002<\/li>\n
    •  \u53f3\u5916\u8054\u63a5\uff08RIGHT OUTER JOIN\uff09\uff1a<\/strong>\u8fd4\u56de\u8868 2 \u4e2d\u7684\u6240\u6709\u8bb0\u5f55\uff0c\u5373\u4f7f\u8868 1 \u4e2d\u4e0d\u5b58\u5728\u5339\u914d\u8bb0\u5f55\u3002<\/li>\n
    •  \u5168\u5916\u8054\u63a5\uff08FULL OUTER JOIN\uff09\uff1a<\/strong>\u8fd4\u56de\u8868 1 \u548c\u8868 2 \u4e2d\u7684\u6240\u6709\u8bb0\u5f55\uff0c\u5373\u4f7f\u6ca1\u6709\u5339\u914d\u8bb0\u5f55\u3002<\/li>\n<\/ul>\n
      \u793a\u4f8b\uff1a<\/strong><\/p>\n
      -- \u5185\u8054\u63a5\nSELECT *\nFROM \u8ba2\u5355\nINNER JOIN \u5ba2\u6237\nON \u8ba2\u5355.\u5ba2\u6237 ID = \u5ba2\u6237.\u5ba2\u6237 ID;\n\n-- \u5de6\u5916\u8054\u63a5\nSELECT *\nFROM \u8ba2\u5355\nLEFT OUTER JOIN \u5ba2\u6237\nON \u8ba2\u5355.\u5ba2\u6237 ID = \u5ba2\u6237.\u5ba2\u6237 ID;\n\n-- \u53f3\u5916\u8054\u63a5\nSELECT *\nFROM \u8ba2\u5355\nRIGHT OUTER JOIN \u5ba2\u6237\nON \u8ba2\u5355.\u5ba2\u6237 ID = \u5ba2\u6237.\u5ba2\u6237 ID;\n\n-- \u5168\u5916\u8054\u63a5\nSELECT *\nFROM \u8ba2\u5355\nFULL OUTER JOIN \u5ba2\u6237\nON \u8ba2\u5355.\u5ba2\u6237 ID = \u5ba2\u6237.\u5ba2\u6237 ID;<\/pre>\n
        \u767b\u5f55\u540e\u590d\u5236   <\/p>\n
      \u4ee5\u4e0a\u5c31\u662fsql\u591a\u8868\u8054\u67e5\u600e\u4e48\u5199\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":"
      sql \u591a\u8868\u8054\u67e5\u5141\u8bb8\u60a8\u4ece\u591a\u4e2a\u8868\u4e2d\u63d0\u53d6\u76f8\u5173\u6570\u636e\u3002\u8bed\u6cd5\u4e3a\uff1aselect \u5217\u540d1, \u5217\u540d2, …from \u8868\u540d1join \u8868\u540d2 on \u8868\u540d1.\u5217\u540d = \u8868\u540d2.\u5217\u540d\u3002\u6b65\u9aa4\u5305\u62ec\uff1a\u786e\u5b9a\u9700\u8981\u5173\u8054\u7684\u8868\u3001\u786e\u5b9a\u8054\u63a5\u5b57\u6bb5\u3001\u4f7f\u7528 join \u8bed\u53e5\u5e76\u6307\u5b9a\u8054\u63a5\u7c7b\u578b\uff0c\u5305\u62ec\u5185\u8054\u63a5\u3001\u5de6\u5916\u8054\u63a5\u3001\u53f3\u5916\u8054\u63a5\u548c\u5168\u5916\u8054\u63a5\u3002 SQL \u591a\u8868\u8054\u67e5 \u5982\u4f55\u7f16\u5199 SQL \u591a\u8868\u8054\u67e5\uff1f \u591a\u8868\u8054\u67e5\u5141\u8bb8\u60a8\u4ece\u591a\u4e2a\u8868\u4e2d\u63d0\u53d6\u76f8\u5173\u6570\u636e\u3002\u5728 SQL \u4e2d\uff0c\u4f7f\u7528 JOIN \u8bed\u53e5\u6267\u884c\u8054\u67e5\u3002 \u8bed\u6cd5\uff1a SELECT \u5217\u540d1, \u5217\u540d2, … FROM \u8868\u540d1 JOIN \u8868\u540d2 ON \u8868\u540d1.\u5217\u540d = \u8868\u540d2.\u5217\u540d JOIN \u8868\u540d3 ON \u8868\u540d2.\u5217\u540d = \u8868\u540d3.\u5217\u540d … \u767b\u5f55\u540e\u590d\u5236 \u6b65\u9aa4\uff1a \u786e\u5b9a\u9700\u8981\u5173\u8054\u7684\u8868\uff1a\u786e\u5b9a\u5305\u542b\u6240\u9700\u6570\u636e\u7684\u8868\u3002 \u786e\u5b9a\u8054\u63a5\u5b57\u6bb5\uff1a\u8bc6\u522b\u5404\u8868\u4e2d\u7528\u4e8e\u5173\u8054\u8bb0\u5f55\u7684\u901a\u7528\u5b57\u6bb5\u3002 \u4f7f\u7528 JOIN \u8bed\u53e5\uff1a\u4f7f\u7528 JOIN \u8bed\u53e5\u5c06\u8868\u94fe\u63a5\u5728\u4e00\u8d77\uff0c\u6307\u5b9a\u8054\u63a5\u5b57\u6bb5\u3002 \u6307\u5b9a\u8054\u63a5\u7c7b\u578b\uff1a\u9009\u62e9\u8054\u63a5\u7c7b\u578b\uff08\u5185\u8054\u63a5\u3001\u5de6\u5916\u8054\u63a5\u3001\u53f3\u5916\u8054\u63a5\u3001\u5168\u5916\u8054\u63a5\uff09\u3002 \u8054\u63a5\u7c7b\u578b\uff1a \u5185\u8054\u63a5\uff08INNER […]<\/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-5693","post","type-post","status-publish","format-standard","hentry","category-16"],"_links":{"self":[{"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/posts\/5693","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=5693"}],"version-history":[{"count":0,"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/posts\/5693\/revisions"}],"wp:attachment":[{"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/media?parent=5693"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/categories?post=5693"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/tags?post=5693"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}