{"id":179416,"date":"2024-11-09T01:38:18","date_gmt":"2024-11-08T17:38:18","guid":{"rendered":"https:\/\/server.hk\/cnblog\/179416\/"},"modified":"2024-11-09T01:38:19","modified_gmt":"2024-11-08T17:38:19","slug":"%e5%a6%82%e4%bd%95%e5%84%aa%e5%8c%96%e6%95%b8%e6%93%9a%e5%ba%ab%e6%9f%a5%e8%a9%a2%e8%aa%9e%e5%8f%a5%ef%bc%9f-%e6%9f%a5%e8%a9%a2%e6%95%b8%e6%93%9a%e5%ba%ab-job-%e8%aa%9e%e5%8f%a5","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/179416\/","title":{"rendered":"\u5982\u4f55\u512a\u5316\u6578\u64da\u5eab\u67e5\u8a62\u8a9e\u53e5\uff1f (\u67e5\u8a62\u6578\u64da\u5eab job \u8a9e\u53e5)"},"content":{"rendered":"

\u5982\u4f55\u512a\u5316\u6578\u64da\u5eab\u67e5\u8a62\u8a9e\u53e5\uff1f (\u67e5\u8a62\u6578\u64da\u5eab job \u8a9e\u53e5)<\/h1>\n

\u5728\u7576\u4eca\u6578\u64da\u9a45\u52d5\u7684\u4e16\u754c\u4e2d\uff0c\u6578\u64da\u5eab\u7684\u6027\u80fd\u5c0d\u65bc\u61c9\u7528\u7a0b\u5e8f\u7684\u6574\u9ad4\u6548\u7387\u81f3\u95dc\u91cd\u8981\u3002\u512a\u5316\u6578\u64da\u5eab\u67e5\u8a62\u8a9e\u53e5\u4e0d\u50c5\u80fd\u63d0\u9ad8\u6578\u64da\u6aa2\u7d22\u7684\u901f\u5ea6\uff0c\u9084\u80fd\u6e1b\u5c11\u4f3a\u670d\u5668\u7684\u8ca0\u64d4\uff0c\u5f9e\u800c\u63d0\u5347\u7528\u6236\u9ad4\u9a57\u3002\u672c\u6587\u5c07\u63a2\u8a0e\u4e00\u4e9b\u6709\u6548\u7684\u6578\u64da\u5eab\u67e5\u8a62\u512a\u5316\u6280\u5de7\uff0c\u5e6b\u52a9\u958b\u767c\u8005\u63d0\u5347\u67e5\u8a62\u6027\u80fd\u3002<\/p>\n

1. \u4f7f\u7528\u7d22\u5f15<\/h2>\n

\u7d22\u5f15\u662f\u6578\u64da\u5eab\u4e2d\u4e00\u7a2e\u91cd\u8981\u7684\u6578\u64da\u7d50\u69cb\uff0c\u53ef\u4ee5\u52a0\u901f\u67e5\u8a62\u64cd\u4f5c\u3002\u901a\u904e\u5728\u8868\u7684\u67d0\u4e9b\u5217\u4e0a\u5275\u5efa\u7d22\u5f15\uff0c\u6578\u64da\u5eab\u53ef\u4ee5\u66f4\u5feb\u5730\u5b9a\u4f4d\u5230\u6240\u9700\u7684\u6578\u64da\u3002\u4ee5\u4e0b\u662f\u5275\u5efa\u7d22\u5f15\u7684\u57fa\u672c\u8a9e\u6cd5\uff1a<\/p>\n

CREATE INDEX index_name ON table_name (column_name);<\/code><\/pre>\n
\u4f8b\u5982\uff0c\u5982\u679c\u6211\u5011\u6709\u4e00\u500b\u7528\u6236\u8868\uff0c\u4e26\u4e14\u7d93\u5e38\u6839\u64da\u7528\u6236\u540d\u67e5\u8a62\uff0c\u53ef\u4ee5\u9019\u6a23\u5275\u5efa\u7d22\u5f15\uff1a<\/p>\n
CREATE INDEX idx_username ON users (username);<\/code><\/pre>\n
2. \u907f\u514d\u4f7f\u7528 SELECT *<\/h2>\n
\u4f7f\u7528 SELECT *<\/code> \u6703\u5c0e\u81f4\u6578\u64da\u5eab\u8fd4\u56de\u8868\u4e2d\u7684\u6240\u6709\u5217\uff0c\u9019\u5728\u67d0\u4e9b\u60c5\u6cc1\u4e0b\u6703\u6d6a\u8cbb\u8cc7\u6e90\u3002\u76f8\u53cd\uff0c\u61c9\u8a72\u53ea\u9078\u64c7\u9700\u8981\u7684\u5217\u3002\u4f8b\u5982\uff1a<\/p>\n
SELECT username, email FROM users WHERE id = 1;<\/code><\/pre>\n
\u9019\u6a23\u4e0d\u50c5\u6e1b\u5c11\u4e86\u6578\u64da\u50b3\u8f38\u7684\u5927\u5c0f\uff0c\u9084\u80fd\u63d0\u9ad8\u67e5\u8a62\u7684\u57f7\u884c\u901f\u5ea6\u3002<\/p>\n
3. \u4f7f\u7528 WHERE \u5b50\u53e5\u904e\u6ffe\u6578\u64da<\/h2>\n
\u5728\u67e5\u8a62\u4e2d\u4f7f\u7528 WHERE<\/code> \u5b50\u53e5\u53ef\u4ee5\u6709\u6548\u5730\u904e\u6ffe\u4e0d\u5fc5\u8981\u7684\u6578\u64da\uff0c\u5f9e\u800c\u6e1b\u5c11\u67e5\u8a62\u7684\u7d50\u679c\u96c6\u3002\u4f8b\u5982\uff1a<\/p>\n
SELECT * FROM orders WHERE status = 'completed';<\/code><\/pre>\n
\u9019\u6a23\u7684\u67e5\u8a62\u53ea\u6703\u8fd4\u56de\u72c0\u614b\u70ba\u201c\u5df2\u5b8c\u6210\u201d\u7684\u8a02\u55ae\uff0c\u5f9e\u800c\u63d0\u9ad8\u67e5\u8a62\u6548\u7387\u3002<\/p>\n
4. \u9069\u7576\u4f7f\u7528 JOIN<\/h2>\n
\u5728\u591a\u500b\u8868\u4e4b\u9593\u9032\u884c\u67e5\u8a62\u6642\uff0c\u4f7f\u7528 JOIN<\/code> \u662f\u5e38\u898b\u7684\u505a\u6cd5\u3002\u7136\u800c\uff0c\u904e\u591a\u7684 JOIN<\/code> \u53ef\u80fd\u6703\u5c0e\u81f4\u6027\u80fd\u4e0b\u964d\u3002\u61c9\u8a72\u6839\u64da\u5be6\u969b\u9700\u6c42\u9078\u64c7\u5408\u9069\u7684 JOIN<\/code> \u985e\u578b\uff0c\u5982 INNER JOIN<\/code>\u3001LEFT JOIN<\/code> \u7b49\uff0c\u4e26\u78ba\u4fdd\u5728\u9023\u63a5\u7684\u5217\u4e0a\u6709\u7d22\u5f15\u3002<\/p>\n
SELECT u.username, o.order_date \nFROM users u \nINNER JOIN orders o ON u.id = o.user_id \nWHERE o.status = 'completed';<\/code><\/pre>\n
5. \u4f7f\u7528 LIMIT \u9650\u5236\u7d50\u679c\u96c6<\/h2>\n
\u5728\u67e5\u8a62\u4e2d\u4f7f\u7528 LIMIT<\/code> \u53ef\u4ee5\u9650\u5236\u8fd4\u56de\u7684\u7d50\u679c\u6578\u91cf\uff0c\u9019\u5c0d\u65bc\u9700\u8981\u5206\u9801\u986f\u793a\u7684\u60c5\u6cc1\u7279\u5225\u6709\u7528\u3002\u4f8b\u5982\uff1a<\/p>\n
SELECT * FROM products LIMIT 10 OFFSET 20;<\/code><\/pre>\n
\u9019\u6a23\u7684\u67e5\u8a62\u5c07\u8fd4\u56de\u5f9e\u7b2c21\u689d\u958b\u59cb\u768410\u689d\u7522\u54c1\u8a18\u9304\uff0c\u6e1b\u5c11\u4e86\u6578\u64da\u7684\u50b3\u8f38\u91cf\u3002<\/p>\n
6. \u5b9a\u671f\u5206\u6790\u548c\u512a\u5316\u6578\u64da\u5eab<\/h2>\n
\u6578\u64da\u5eab\u7ba1\u7406\u7cfb\u7d71\u901a\u5e38\u63d0\u4f9b\u5de5\u5177\u4f86\u5206\u6790\u67e5\u8a62\u6027\u80fd\u548c\u6578\u64da\u5eab\u7d50\u69cb\u3002\u5b9a\u671f\u4f7f\u7528\u9019\u4e9b\u5de5\u5177\u4f86\u6aa2\u67e5\u6162\u67e5\u8a62\uff0c\u4e26\u6839\u64da\u5206\u6790\u7d50\u679c\u9032\u884c\u512a\u5316\uff0c\u53ef\u4ee5\u986f\u8457\u63d0\u9ad8\u6578\u64da\u5eab\u7684\u6574\u9ad4\u6027\u80fd\u3002<\/p>\n
7. \u4f7f\u7528\u7de9\u5b58\u6280\u8853<\/h2>\n
\u7de9\u5b58\u53ef\u4ee5\u986f\u8457\u63d0\u9ad8\u67e5\u8a62\u6027\u80fd\uff0c\u7279\u5225\u662f\u5c0d\u65bc\u983b\u7e41\u8a2a\u554f\u7684\u6578\u64da\u3002\u53ef\u4ee5\u4f7f\u7528\u5167\u5b58\u7de9\u5b58\u7cfb\u7d71\uff08\u5982 Redis \u6216 Memcached\uff09\u4f86\u5b58\u5132\u67e5\u8a62\u7d50\u679c\uff0c\u5f9e\u800c\u6e1b\u5c11\u5c0d\u6578\u64da\u5eab\u7684\u76f4\u63a5\u67e5\u8a62\u3002<\/p>\n
\u7e3d\u7d50<\/h2>\n
\u512a\u5316\u6578\u64da\u5eab\u67e5\u8a62\u8a9e\u53e5\u662f\u4e00\u500b\u6301\u7e8c\u7684\u904e\u7a0b\uff0c\u6d89\u53ca\u591a\u7a2e\u6280\u8853\u548c\u7b56\u7565\u3002\u901a\u904e\u4f7f\u7528\u7d22\u5f15\u3001\u907f\u514d\u4e0d\u5fc5\u8981\u7684\u5217\u9078\u64c7\u3001\u5408\u7406\u4f7f\u7528 JOIN<\/code> \u548c WHERE<\/code> \u5b50\u53e5\u3001\u9650\u5236\u7d50\u679c\u96c6\u4ee5\u53ca\u5b9a\u671f\u5206\u6790\u6578\u64da\u5eab\u6027\u80fd\uff0c\u958b\u767c\u8005\u53ef\u4ee5\u986f\u8457\u63d0\u9ad8\u67e5\u8a62\u6548\u7387\u3002\u5c0d\u65bc\u9700\u8981\u9ad8\u6027\u80fd\u6578\u64da\u5eab\u89e3\u6c7a\u65b9\u6848\u7684\u7528\u6236\uff0c\u9078\u64c7\u5408\u9069\u7684 VPS<\/a> \u6216 \u9999\u6e2f\u4f3a\u670d\u5668<\/a> \u4e5f\u662f\u4e00\u500b\u91cd\u8981\u7684\u8003\u91cf\u3002\u5e0c\u671b\u9019\u4e9b\u6280\u5de7\u80fd\u5e6b\u52a9\u60a8\u5728\u6578\u64da\u5eab\u7ba1\u7406\u4e2d\u53d6\u5f97\u66f4\u597d\u7684\u6548\u679c\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"
\u5b78\u7fd2\u5982\u4f55\u512a\u5316\u6578\u64da\u5eab\u67e5\u8a62\u8a9e\u53e5\uff0c\u63d0\u9ad8\u67e5\u8a62\u6548\u7387\uff0c\u6e1b\u5c11\u57f7\u884c\u6642\u9593\uff0c\u63d0\u5347\u6574\u9ad4\u7cfb\u7d71\u6027\u80fd\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-179416","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/179416","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=179416"}],"version-history":[{"count":1,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/179416\/revisions"}],"predecessor-version":[{"id":179417,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/179416\/revisions\/179417"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=179416"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=179416"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=179416"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}