{"id":5732,"date":"2024-11-14T08:13:55","date_gmt":"2024-11-14T00:13:55","guid":{"rendered":"https:\/\/fwq.ai\/blog\/5732\/"},"modified":"2024-11-14T08:13:55","modified_gmt":"2024-11-14T00:13:55","slug":"sql%e9%99%8d%e5%ba%8f%e7%b4%a2%e5%bc%95%e6%80%8e%e4%b9%88%e5%bc%84","status":"publish","type":"post","link":"https:\/\/fwq.ai\/blog\/5732\/","title":{"rendered":"sql\u964d\u5e8f\u7d22\u5f15\u600e\u4e48\u5f04"},"content":{"rendered":"

\n \u964d\u5e8f\u7d22\u5f15\u662f\u4e00\u79cd\u6392\u5217\u6570\u636e\u8868\u4e2d\u503c\u4ece\u5927\u5230\u5c0f\u7684\u7279\u6b8a\u7d22\u5f15\uff0c\u53ef\u63d0\u9ad8\u6309\u964d\u5e8f\u503c\u67e5\u8be2\u7684\u6548\u7387\u3002\u521b\u5efa\u964d\u5e8f\u7d22\u5f15\u7684\u6b65\u9aa4\u5305\u62ec\uff1a\u786e\u5b9a\u8981\u7d22\u5f15\u7684\u5217\u3001\u521b\u5efa\u7d22\u5f15\u8bed\u53e5\uff08\u4f8b\u5982\uff1acreate index\uff09\u3001\u4f7f\u7528\u7d22\u5f15\uff08\u4f8b\u5982\uff1aorder by desc\uff09\u3002\u964d\u5e8f\u7d22\u5f15\u4f18\u70b9\uff1a\u4f18\u5316\u964d\u5e8f\u67e5\u8be2\u6027\u80fd\u3001\u51cf\u5c11\u626b\u63cf\u6570\u636e\u91cf\u3001\u63d0\u9ad8\u6392\u5e8f\u6548\u7387\uff1b\u7f3a\u70b9\uff1a\u989d\u5916\u5b58\u50a8\u7a7a\u95f4\u3001\u53ef\u80fd\u5f71\u54cd\u5347\u5e8f\u67e5\u8be2\u6027\u80fd\u3002\u5728\u9700\u8981\u9891\u7e41\u6309\u964d\u5e8f\u503c\u67e5\u8be2\u65f6\u624d\u521b\u5efa\u964d\u5e8f\u7d22\u5f15\u3002\n<\/p><\/blockquote>\n

\"sql\u964d\u5e8f\u7d22\u5f15\u600e\u4e48\u5f04\u63d2\u56fe\"<\/p>\n

SQL \u964d\u5e8f\u7d22\u5f15\u521b\u5efa\u65b9\u6cd5<\/strong><\/p>\n

\u964d\u5e8f\u7d22\u5f15\u5b9a\u4e49<\/strong><\/p>\n

\u964d\u5e8f\u7d22\u5f15\u662f\u4e00\u79cd\u7279\u6b8a\u7c7b\u578b\u7684\u7d22\u5f15\uff0c\u5b83\u5c06\u6570\u636e\u8868\u4e2d\u7684\u503c\u4ee5\u4ece\u5927\u5230\u5c0f\u7684\u987a\u5e8f\u8fdb\u884c\u3002\u8fd9\u4f7f\u5f97\u9488\u5bf9\u964d\u5e8f\u503c\u7684\u67e5\u8be2\u66f4\u52a0\u9ad8\u6548\u3002<\/p>\n

\u521b\u5efa\u964d\u5e8f\u7d22\u5f15\u7684\u6b65\u9aa4<\/strong><\/p>\n

(1) \u786e\u5b9a\u8981\u521b\u5efa\u964d\u5e8f\u7d22\u5f15\u7684\u5217<\/strong><\/p>\n

\u8003\u8651\u9700\u8981\u7ecf\u5e38\u6309\u964d\u5e8f\u6392\u5e8f\u63d0\u53d6\u6570\u636e\u7684\u5217\u3002<\/p>\n

(2) \u521b\u5efa\u964d\u5e8f\u7d22\u5f15\u8bed\u53e5<\/strong><\/p>\n

CREATE INDEX <\u7d22\u5f15\u540d\u79f0> ON <\u8868\u540d\u79f0> (<\u5217\u540d\u79f0>) DESC;<\/pre>\n
 \u767b\u5f55\u540e\u590d\u5236 <\/p>\n
\u4f8b\u5982\uff0c\u8981\u5728\u540d\u4e3a customers \u7684\u8868\u4e2d\u521b\u5efa\u4e00\u4e2a\u540d\u4e3a last_name_idx \u7684\u964d\u5e8f\u7d22\u5f15\uff0c\u6309 last_name \u5217\u5bf9\u6570\u636e\u8fdb\u884c\u6392\u5e8f\uff1a<\/p>\n
CREATE INDEX last_name_idx ON customers (last_name) DESC;<\/pre>\n
 \u767b\u5f55\u540e\u590d\u5236 <\/p>\n
(3) \u4f7f\u7528\u964d\u5e8f\u7d22\u5f15<\/strong><\/p>\n
\u4f7f\u7528 ORDER BY \u5b50\u53e5\u4e2d\u7684 DESC \u5173\u952e\u5b57\u6309\u964d\u5e8f\u6392\u5e8f\u67e5\u8be2\u7ed3\u679c\uff1a<\/p>\n
SELECT * FROM customers ORDER BY last_name DESC;<\/pre>\n
 \u767b\u5f55\u540e\u590d\u5236 <\/p>\n
\u964d\u5e8f\u7d22\u5f15\u7684\u4f18\u70b9<\/strong><\/p>\n
    \n
  • \u4f18\u5316\u6309\u964d\u5e8f\u503c\u8fdb\u884c\u67e5\u8be2\u7684\u6027\u80fd\u3002<\/li>\n
  • \u51cf\u5c11\u9700\u8981\u626b\u63cf\u7684\u6570\u636e\u91cf\u3002<\/li>\n
  • \u63d0\u9ad8\u6392\u5e8f\u64cd\u4f5c\u7684\u6548\u7387\u3002<\/li>\n<\/ul>\n
    \u964d\u5e8f\u7d22\u5f15\u7684\u7f3a\u70b9<\/strong><\/p>\n
      \n
    • \u521b\u5efa\u548c\u7ef4\u62a4\u7d22\u5f15\u9700\u8981\u989d\u5916\u7684\u5b58\u50a8\u7a7a\u95f4\u548c\u8ba1\u7b97\u8d44\u6e90\u3002<\/li>\n
    • \u53ef\u80fd\u4f1a\u5f71\u54cd\u6309\u5347\u5e8f\u503c\u8fdb\u884c\u67e5\u8be2\u7684\u6027\u80fd\u3002<\/li>\n<\/ul>\n
      \u6ce8\u610f\u4e8b\u9879<\/strong><\/p>\n
        \n
      • \u4ec5\u5728\u9700\u8981\u6309\u964d\u5e8f\u503c\u8fdb\u884c\u9891\u7e41\u67e5\u8be2\u65f6\u624d\u521b\u5efa\u964d\u5e8f\u7d22\u5f15\u3002<\/li>\n
      • \u907f\u514d\u5728\u5c0f\u578b\u6570\u636e\u96c6\u6216\u4e0d\u9891\u7e41\u4f7f\u7528\u6392\u5e8f\u64cd\u4f5c\u7684\u5217\u4e0a\u521b\u5efa\u964d\u5e8f\u7d22\u5f15\u3002<\/li>\n
      • \u8003\u8651\u521b\u5efa\u590d\u5408\u7d22\u5f15\u4ee5\u4f18\u5316\u6d89\u53ca\u591a\u4e2a\u5217\u7684\u964d\u5e8f\u67e5\u8be2\u3002<\/li>\n<\/ul>\n
        \u4ee5\u4e0a\u5c31\u662fsql\u964d\u5e8f\u7d22\u5f15\u600e\u4e48\u5f04\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":"
        \u964d\u5e8f\u7d22\u5f15\u662f\u4e00\u79cd\u6392\u5217\u6570\u636e\u8868\u4e2d\u503c\u4ece\u5927\u5230\u5c0f\u7684\u7279\u6b8a\u7d22\u5f15\uff0c\u53ef\u63d0\u9ad8\u6309\u964d\u5e8f\u503c\u67e5\u8be2\u7684\u6548\u7387\u3002\u521b\u5efa\u964d\u5e8f\u7d22\u5f15\u7684\u6b65\u9aa4\u5305\u62ec\uff1a\u786e\u5b9a\u8981\u7d22\u5f15\u7684\u5217\u3001\u521b\u5efa\u7d22\u5f15\u8bed\u53e5\uff08\u4f8b\u5982\uff1acreate index\uff09\u3001\u4f7f\u7528\u7d22\u5f15\uff08\u4f8b\u5982\uff1aorder by desc\uff09\u3002\u964d\u5e8f\u7d22\u5f15\u4f18\u70b9\uff1a\u4f18\u5316\u964d\u5e8f\u67e5\u8be2\u6027\u80fd\u3001\u51cf\u5c11\u626b\u63cf\u6570\u636e\u91cf\u3001\u63d0\u9ad8\u6392\u5e8f\u6548\u7387\uff1b\u7f3a\u70b9\uff1a\u989d\u5916\u5b58\u50a8\u7a7a\u95f4\u3001\u53ef\u80fd\u5f71\u54cd\u5347\u5e8f\u67e5\u8be2\u6027\u80fd\u3002\u5728\u9700\u8981\u9891\u7e41\u6309\u964d\u5e8f\u503c\u67e5\u8be2\u65f6\u624d\u521b\u5efa\u964d\u5e8f\u7d22\u5f15\u3002 SQL \u964d\u5e8f\u7d22\u5f15\u521b\u5efa\u65b9\u6cd5 \u964d\u5e8f\u7d22\u5f15\u5b9a\u4e49 \u964d\u5e8f\u7d22\u5f15\u662f\u4e00\u79cd\u7279\u6b8a\u7c7b\u578b\u7684\u7d22\u5f15\uff0c\u5b83\u5c06\u6570\u636e\u8868\u4e2d\u7684\u503c\u4ee5\u4ece\u5927\u5230\u5c0f\u7684\u987a\u5e8f\u8fdb\u884c\u3002\u8fd9\u4f7f\u5f97\u9488\u5bf9\u964d\u5e8f\u503c\u7684\u67e5\u8be2\u66f4\u52a0\u9ad8\u6548\u3002 \u521b\u5efa\u964d\u5e8f\u7d22\u5f15\u7684\u6b65\u9aa4 (1) \u786e\u5b9a\u8981\u521b\u5efa\u964d\u5e8f\u7d22\u5f15\u7684\u5217 \u8003\u8651\u9700\u8981\u7ecf\u5e38\u6309\u964d\u5e8f\u6392\u5e8f\u63d0\u53d6\u6570\u636e\u7684\u5217\u3002 (2) \u521b\u5efa\u964d\u5e8f\u7d22\u5f15\u8bed\u53e5 CREATE INDEX <\u7d22\u5f15\u540d\u79f0> ON <\u8868\u540d\u79f0> (<\u5217\u540d\u79f0>) DESC; \u767b\u5f55\u540e\u590d\u5236 \u4f8b\u5982\uff0c\u8981\u5728\u540d\u4e3a customers \u7684\u8868\u4e2d\u521b\u5efa\u4e00\u4e2a\u540d\u4e3a last_name_idx \u7684\u964d\u5e8f\u7d22\u5f15\uff0c\u6309 last_name \u5217\u5bf9\u6570\u636e\u8fdb\u884c\u6392\u5e8f\uff1a CREATE INDEX last_name_idx ON customers (last_name) DESC; \u767b\u5f55\u540e\u590d\u5236 (3) \u4f7f\u7528\u964d\u5e8f\u7d22\u5f15 \u4f7f\u7528 ORDER BY \u5b50\u53e5\u4e2d\u7684 DESC \u5173\u952e\u5b57\u6309\u964d\u5e8f\u6392\u5e8f\u67e5\u8be2\u7ed3\u679c\uff1a SELECT * FROM customers ORDER BY last_name DESC; \u767b\u5f55\u540e\u590d\u5236 \u964d\u5e8f\u7d22\u5f15\u7684\u4f18\u70b9 […]<\/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-5732","post","type-post","status-publish","format-standard","hentry","category-16"],"_links":{"self":[{"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/posts\/5732","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=5732"}],"version-history":[{"count":0,"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/posts\/5732\/revisions"}],"wp:attachment":[{"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/media?parent=5732"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/categories?post=5732"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/tags?post=5732"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}