{"id":186558,"date":"2024-11-11T06:55:15","date_gmt":"2024-11-10T22:55:15","guid":{"rendered":"https:\/\/server.hk\/cnblog\/186558\/"},"modified":"2024-11-11T06:55:16","modified_gmt":"2024-11-10T22:55:16","slug":"%e6%95%b8%e6%93%9a%e5%ba%ab%e9%ab%98%e7%b4%9a%e7%af%a9%e9%81%b8%e6%8a%80%e5%b7%a7%ef%bc%88%e6%80%8e%e6%a8%a3%e9%ab%98%e7%b4%9a%e7%af%a9%e9%81%b8%e6%95%b8%e6%93%9a%e5%ba%ab%ef%bc%89","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/186558\/","title":{"rendered":"\u6578\u64da\u5eab\u9ad8\u7d1a\u7be9\u9078\u6280\u5de7\uff08\u600e\u6a23\u9ad8\u7d1a\u7be9\u9078\u6578\u64da\u5eab\uff09"},"content":{"rendered":"

\u6578\u64da\u5eab\u9ad8\u7d1a\u7be9\u9078\u6280\u5de7\uff08\u600e\u6a23\u9ad8\u7d1a\u7be9\u9078\u6578\u64da\u5eab\uff09<\/h1>\n

\u5728\u7576\u4eca\u6578\u64da\u9a45\u52d5\u7684\u4e16\u754c\u4e2d\uff0c\u6578\u64da\u5eab\u7684\u7ba1\u7406\u548c\u7be9\u9078\u8b8a\u5f97\u8d8a\u4f86\u8d8a\u91cd\u8981\u3002\u7121\u8ad6\u662f\u4f01\u696d\u9084\u662f\u500b\u4eba\uff0c\u80fd\u5920\u6709\u6548\u5730\u7be9\u9078\u548c\u67e5\u8a62\u6578\u64da\u90fd\u662f\u4e00\u9805\u95dc\u9375\u6280\u80fd\u3002\u672c\u6587\u5c07\u63a2\u8a0e\u4e00\u4e9b\u9ad8\u7d1a\u7be9\u9078\u6280\u5de7\uff0c\u5e6b\u52a9\u60a8\u66f4\u9ad8\u6548\u5730\u64cd\u4f5c\u6578\u64da\u5eab\u3002<\/p>\n

1. \u4f7f\u7528\u8907\u96dc\u7684\u67e5\u8a62\u8a9e\u53e5<\/h2>\n

\u5728\u6578\u64da\u5eab\u4e2d\uff0c\u67e5\u8a62\u8a9e\u53e5\u662f\u7be9\u9078\u6578\u64da\u7684\u4e3b\u8981\u5de5\u5177\u3002\u4f7f\u7528 SQL\uff08\u7d50\u69cb\u5316\u67e5\u8a62\u8a9e\u8a00\uff09\u53ef\u4ee5\u8b93\u60a8\u9032\u884c\u8907\u96dc\u7684\u67e5\u8a62\u3002\u4f8b\u5982\uff0c\u60a8\u53ef\u4ee5\u4f7f\u7528 JOIN<\/code> \u8a9e\u53e5\u4f86\u9023\u63a5\u591a\u500b\u8868\uff0c\u5f9e\u800c\u7372\u53d6\u66f4\u5168\u9762\u7684\u6578\u64da\u3002<\/p>\n

SELECT a.name, b.order_date \nFROM customers a \nJOIN orders b ON a.id = b.customer_id \nWHERE b.order_total > 100;<\/code><\/pre>\n
\u4e0a\u8ff0\u67e5\u8a62\u5c07\u8fd4\u56de\u6240\u6709\u8a02\u55ae\u7e3d\u984d\u8d85\u904e 100 \u7684\u5ba2\u6236\u540d\u7a31\u53ca\u5176\u8a02\u55ae\u65e5\u671f\u3002\u9019\u7a2e\u65b9\u6cd5\u53ef\u4ee5\u5e6b\u52a9\u60a8\u5f9e\u591a\u500b\u6578\u64da\u8868\u4e2d\u63d0\u53d6\u6709\u7528\u7684\u4fe1\u606f\u3002<\/p>\n
2. \u4f7f\u7528\u7be9\u9078\u689d\u4ef6<\/h2>\n
\u5728\u9032\u884c\u6578\u64da\u7be9\u9078\u6642\uff0c\u4f7f\u7528 WHERE<\/code> \u5b50\u53e5\u53ef\u4ee5\u5e6b\u52a9\u60a8\u7cbe\u78ba\u5b9a\u4f4d\u6240\u9700\u6578\u64da\u3002\u60a8\u53ef\u4ee5\u4f7f\u7528\u591a\u500b\u689d\u4ef6\u4f86\u9032\u884c\u7be9\u9078\uff0c\u4e26\u4f7f\u7528\u908f\u8f2f\u904b\u7b97\u7b26\uff08\u5982 AND<\/code> \u548c OR<\/code>\uff09\u4f86\u7d44\u5408\u9019\u4e9b\u689d\u4ef6\u3002<\/p>\n
SELECT * \nFROM products \nWHERE category = 'Electronics' \nAND price BETWEEN 100 AND 500;<\/code><\/pre>\n
\u9019\u500b\u67e5\u8a62\u5c07\u8fd4\u56de\u6240\u6709\u985e\u5225\u70ba\u96fb\u5b50\u7522\u54c1\u4e14\u50f9\u683c\u5728 100 \u5230 500 \u4e4b\u9593\u7684\u7522\u54c1\u3002\u9019\u6a23\u7684\u7be9\u9078\u53ef\u4ee5\u5e6b\u52a9\u7528\u6236\u5feb\u901f\u627e\u5230\u7b26\u5408\u7279\u5b9a\u9700\u6c42\u7684\u6578\u64da\u3002<\/p>\n
3. \u4f7f\u7528\u805a\u5408\u51fd\u6578<\/h2>\n
\u805a\u5408\u51fd\u6578\u5982 COUNT<\/code>\u3001SUM<\/code>\u3001AVG<\/code> \u7b49\u53ef\u4ee5\u5e6b\u52a9\u60a8\u5c0d\u6578\u64da\u9032\u884c\u7d71\u8a08\u5206\u6790\u3002\u9019\u4e9b\u51fd\u6578\u53ef\u4ee5\u8207 GROUP BY<\/code> \u5b50\u53e5\u7d50\u5408\u4f7f\u7528\uff0c\u4ee5\u4fbf\u5c0d\u6578\u64da\u9032\u884c\u5206\u7d44\u548c\u8a08\u7b97\u3002<\/p>\n
SELECT category, COUNT(*) as total_products \nFROM products \nGROUP BY category;<\/code><\/pre>\n
\u9019\u500b\u67e5\u8a62\u5c07\u8fd4\u56de\u6bcf\u500b\u7522\u54c1\u985e\u5225\u7684\u7522\u54c1\u7e3d\u6578\uff0c\u5e6b\u52a9\u60a8\u4e86\u89e3\u5404\u985e\u5225\u7684\u7522\u54c1\u5206\u4f48\u60c5\u6cc1\u3002<\/p>\n
4. \u4f7f\u7528\u7d22\u5f15\u63d0\u9ad8\u67e5\u8a62\u6548\u7387<\/h2>\n
\u5728\u5927\u578b\u6578\u64da\u5eab\u4e2d\uff0c\u67e5\u8a62\u6548\u7387\u81f3\u95dc\u91cd\u8981\u3002\u4f7f\u7528\u7d22\u5f15\u53ef\u4ee5\u986f\u8457\u63d0\u9ad8\u67e5\u8a62\u901f\u5ea6\u3002\u7d22\u5f15\u662f\u6578\u64da\u5eab\u4e2d\u4e00\u7a2e\u7279\u6b8a\u7684\u6578\u64da\u7d50\u69cb\uff0c\u53ef\u4ee5\u52a0\u901f\u6578\u64da\u6aa2\u7d22\u3002<\/p>\n
CREATE INDEX idx_product_name \nON products (name);<\/code><\/pre>\n
\u901a\u904e\u5728\u7522\u54c1\u540d\u7a31\u4e0a\u5275\u5efa\u7d22\u5f15\uff0c\u60a8\u53ef\u4ee5\u52a0\u5feb\u57fa\u65bc\u7522\u54c1\u540d\u7a31\u7684\u67e5\u8a62\u901f\u5ea6\u3002\u9019\u5c0d\u65bc\u9700\u8981\u983b\u7e41\u67e5\u8a62\u7684\u5b57\u6bb5\u7279\u5225\u6709\u6548\u3002<\/p>\n
5. \u4f7f\u7528\u5b50\u67e5\u8a62<\/h2>\n
\u5b50\u67e5\u8a62\u662f\u5d4c\u5957\u5728\u5176\u4ed6\u67e5\u8a62\u4e2d\u7684\u67e5\u8a62\uff0c\u53ef\u4ee5\u7528\u4f86\u9032\u884c\u66f4\u8907\u96dc\u7684\u7be9\u9078\u3002\u4f8b\u5982\uff0c\u60a8\u53ef\u4ee5\u4f7f\u7528\u5b50\u67e5\u8a62\u4f86\u67e5\u627e\u67d0\u4e9b\u689d\u4ef6\u4e0b\u7684\u6578\u64da\u3002<\/p>\n
SELECT name \nFROM customers \nWHERE id IN (SELECT customer_id \n              FROM orders \n              WHERE order_total > 100);<\/code><\/pre>\n
\u9019\u500b\u67e5\u8a62\u5c07\u8fd4\u56de\u6240\u6709\u4e0b\u904e\u8a02\u55ae\u4e14\u8a02\u55ae\u7e3d\u984d\u8d85\u904e 100 \u7684\u5ba2\u6236\u540d\u7a31\u3002\u5b50\u67e5\u8a62\u7684\u4f7f\u7528\u4f7f\u5f97\u67e5\u8a62\u66f4\u52a0\u9748\u6d3b\u548c\u5f37\u5927\u3002<\/p>\n
\u7e3d\u7d50<\/h2>\n
\u638c\u63e1\u6578\u64da\u5eab\u7684\u9ad8\u7d1a\u7be9\u9078\u6280\u5de7\u4e0d\u50c5\u80fd\u63d0\u9ad8\u5de5\u4f5c\u6548\u7387\uff0c\u9084\u80fd\u5e6b\u52a9\u60a8\u66f4\u597d\u5730\u5206\u6790\u548c\u5229\u7528\u6578\u64da\u3002\u901a\u904e\u4f7f\u7528\u8907\u96dc\u7684\u67e5\u8a62\u8a9e\u53e5\u3001\u7be9\u9078\u689d\u4ef6\u3001\u805a\u5408\u51fd\u6578\u3001\u7d22\u5f15\u548c\u5b50\u67e5\u8a62\uff0c\u60a8\u53ef\u4ee5\u66f4\u7cbe\u78ba\u5730\u7372\u53d6\u6240\u9700\u7684\u4fe1\u606f\u3002\u5c0d\u65bc\u9700\u8981\u9ad8\u6548\u6578\u64da\u8655\u7406\u7684\u4f01\u696d\u4f86\u8aaa\uff0c\u9078\u64c7\u5408\u9069\u7684 VPS<\/a> \u6216 \u9999\u6e2f\u4f3a\u670d\u5668<\/a> \u89e3\u6c7a\u65b9\u6848\u4e5f\u662f\u81f3\u95dc\u91cd\u8981\u7684\uff0c\u9019\u5c07\u70ba\u60a8\u7684\u6578\u64da\u5eab\u64cd\u4f5c\u63d0\u4f9b\u7a69\u5b9a\u7684\u652f\u6301\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"
\u638c\u63e1\u6578\u64da\u5eab\u9ad8\u7d1a\u7be9\u9078\u6280\u5de7\uff0c\u63d0\u5347\u6578\u64da\u67e5\u8a62\u6548\u7387\uff0c\u7cbe\u78ba\u7372\u53d6\u6240\u9700\u4fe1\u606f\uff0c\u52a9\u529b\u6578\u64da\u5206\u6790\u8207\u6c7a\u7b56\u3002<\/p>\n","protected":false},"author":0,"featured_media":0,"comment_status":"closed","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[101],"tags":[],"class_list":["post-186558","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/186558","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/types\/post"}],"replies":[{"embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/comments?post=186558"}],"version-history":[{"count":1,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/186558\/revisions"}],"predecessor-version":[{"id":186559,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/186558\/revisions\/186559"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=186558"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=186558"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=186558"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}