{"id":195157,"date":"2024-11-13T12:41:20","date_gmt":"2024-11-13T04:41:20","guid":{"rendered":"https:\/\/server.hk\/cnblog\/195157\/"},"modified":"2024-11-13T12:41:21","modified_gmt":"2024-11-13T04:41:21","slug":"%e5%84%aa%e5%8c%96sql%e8%aa%9e%e5%8f%a5%ef%bc%8c%e5%8d%81%e6%a2%9d%e5%bb%ba%e8%ad%b0%e8%ae%93sql%e9%80%9f%e5%ba%a6%e9%a3%9b%e8%b5%b7%e4%be%86","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/195157\/","title":{"rendered":"\u512a\u5316SQL\u8a9e\u53e5\uff0c\u5341\u689d\u5efa\u8b70\u8b93SQL\u901f\u5ea6\u98db\u8d77\u4f86"},"content":{"rendered":"<h1 id=\"%e5%84%aa%e5%8c%96sql%e8%aa%9e%e5%8f%a5%ef%bc%8c%e5%8d%81%e6%a2%9d%e5%bb%ba%e8%ad%b0%e8%ae%93sql%e9%80%9f%e5%ba%a6%e9%a3%9b%e8%b5%b7%e4%be%86-cbDRdSoeWc\">\u512a\u5316SQL\u8a9e\u53e5\uff0c\u5341\u689d\u5efa\u8b70\u8b93SQL\u901f\u5ea6\u98db\u8d77\u4f86<\/h1>\n<p>\u5728\u7576\u4eca\u6578\u64da\u9a45\u52d5\u7684\u4e16\u754c\u4e2d\uff0cSQL\uff08\u7d50\u69cb\u5316\u67e5\u8a62\u8a9e\u8a00\uff09\u662f\u8207\u6578\u64da\u5eab\u4ea4\u4e92\u7684\u4e3b\u8981\u5de5\u5177\u3002\u7121\u8ad6\u662f\u5927\u578b\u4f01\u696d\u9084\u662f\u5c0f\u578b\u521d\u5275\u516c\u53f8\uff0c\u512a\u5316SQL\u8a9e\u53e5\u4ee5\u63d0\u9ad8\u67e5\u8a62\u6027\u80fd\u90fd\u662f\u81f3\u95dc\u91cd\u8981\u7684\u3002\u672c\u6587\u5c07\u63d0\u4f9b\u5341\u689d\u5efa\u8b70\uff0c\u5e6b\u52a9\u60a8\u512a\u5316SQL\u8a9e\u53e5\uff0c\u8b93SQL\u901f\u5ea6\u98db\u8d77\u4f86\u3002<\/p>\n<h2 id=\"1-%e4%bd%bf%e7%94%a8%e7%b4%a2%e5%bc%95-cbDRdSoeWc\">1. \u4f7f\u7528\u7d22\u5f15<\/h2>\n<p>\u7d22\u5f15\u662f\u63d0\u9ad8\u67e5\u8a62\u901f\u5ea6\u7684\u95dc\u9375\u3002\u901a\u904e\u5728\u7d93\u5e38\u67e5\u8a62\u7684\u5217\u4e0a\u5275\u5efa\u7d22\u5f15\uff0c\u53ef\u4ee5\u986f\u8457\u6e1b\u5c11\u67e5\u8a62\u7684\u57f7\u884c\u6642\u9593\u3002\u8209\u4f8b\u4f86\u8aaa\uff0c\u5c0d\u65bc\u4e00\u500b\u5305\u542b\u5927\u91cf\u6578\u64da\u7684\u7528\u6236\u8868\uff0c\u5c0d\u7528\u6236ID\u5217\u5275\u5efa\u7d22\u5f15\u53ef\u4ee5\u52a0\u5feb\u67e5\u8a62\u901f\u5ea6\uff1a<\/p>\n<pre><code>CREATE INDEX idx_user_id ON users(user_id);<\/code><\/pre>\n<h2 id=\"2-%e9%81%bf%e5%85%8dselect-cbDRdSoeWc\">2. \u907f\u514dSELECT *<\/h2>\n<p>\u4f7f\u7528SELECT *\u6703\u5c0e\u81f4\u4e0d\u5fc5\u8981\u7684\u6578\u64da\u50b3\u8f38\uff0c\u7279\u5225\u662f\u5728\u8868\u4e2d\u6709\u8a31\u591a\u5217\u6642\u3002\u61c9\u8a72\u660e\u78ba\u6307\u5b9a\u9700\u8981\u7684\u5217\uff0c\u4ee5\u6e1b\u5c11\u6578\u64da\u91cf\uff1a<\/p>\n<pre><code>SELECT user_id, username FROM users;<\/code><\/pre>\n<h2 id=\"3-%e4%bd%bf%e7%94%a8join%e8%80%8c%e9%9d%9e%e5%ad%90%e6%9f%a5%e8%a9%a2-cbDRdSoeWc\">3. \u4f7f\u7528JOIN\u800c\u975e\u5b50\u67e5\u8a62<\/h2>\n<p>\u5728\u8a31\u591a\u60c5\u6cc1\u4e0b\uff0c\u4f7f\u7528JOIN\u6bd4\u4f7f\u7528\u5b50\u67e5\u8a62\u66f4\u6709\u6548\u7387\u3002JOIN\u53ef\u4ee5\u5728\u55ae\u4e00\u67e5\u8a62\u4e2d\u7372\u53d6\u6240\u9700\u7684\u6578\u64da\uff0c\u5f9e\u800c\u6e1b\u5c11\u67e5\u8a62\u7684\u8907\u96dc\u6027\u548c\u57f7\u884c\u6642\u9593\uff1a<\/p>\n<pre><code>SELECT u.username, o.order_id \nFROM users u \nJOIN orders o ON u.user_id = o.user_id;<\/code><\/pre>\n<h2 id=\"4-%e9%81%a9%e7%95%b6%e4%bd%bf%e7%94%a8where%e5%ad%90%e5%8f%a5-cbDRdSoeWc\">4. \u9069\u7576\u4f7f\u7528WHERE\u5b50\u53e5<\/h2>\n<p>\u5728\u67e5\u8a62\u4e2d\u4f7f\u7528WHERE\u5b50\u53e5\u53ef\u4ee5\u904e\u6ffe\u4e0d\u5fc5\u8981\u7684\u6578\u64da\uff0c\u5f9e\u800c\u63d0\u9ad8\u67e5\u8a62\u6548\u7387\u3002\u78ba\u4fdd\u5728WHERE\u5b50\u53e5\u4e2d\u4f7f\u7528\u7d22\u5f15\u5217\uff0c\u4ee5\u4fbf\u66f4\u5feb\u5730\u5b9a\u4f4d\u6578\u64da\uff1a<\/p>\n<pre><code>SELECT * FROM orders WHERE order_date &gt; '2023-01-01';<\/code><\/pre>\n<h2 id=\"5-%e9%81%bf%e5%85%8d%e4%bd%bf%e7%94%a8or-cbDRdSoeWc\">5. \u907f\u514d\u4f7f\u7528OR<\/h2>\n<p>\u4f7f\u7528OR\u6703\u5c0e\u81f4\u67e5\u8a62\u6027\u80fd\u4e0b\u964d\uff0c\u56e0\u70ba\u6578\u64da\u5eab\u9700\u8981\u6aa2\u67e5\u591a\u500b\u689d\u4ef6\u3002\u53ef\u4ee5\u8003\u616e\u4f7f\u7528UNION\u4f86\u66ff\u4ee3OR\uff0c\u9019\u6a23\u53ef\u4ee5\u63d0\u9ad8\u67e5\u8a62\u6548\u7387\uff1a<\/p>\n<pre><code>SELECT * FROM orders WHERE status = 'shipped' \nUNION \nSELECT * FROM orders WHERE status = 'delivered';<\/code><\/pre>\n<h2 id=\"6-%e4%bd%bf%e7%94%a8limit%e9%99%90%e5%88%b6%e7%b5%90%e6%9e%9c%e9%9b%86-cbDRdSoeWc\">6. \u4f7f\u7528LIMIT\u9650\u5236\u7d50\u679c\u96c6<\/h2>\n<p>\u5728\u67e5\u8a62\u4e2d\u4f7f\u7528LIMIT\u53ef\u4ee5\u9650\u5236\u8fd4\u56de\u7684\u7d50\u679c\u96c6\u5927\u5c0f\uff0c\u9019\u5c0d\u65bc\u63d0\u9ad8\u6027\u80fd\u5c24\u5176\u91cd\u8981\uff0c\u7279\u5225\u662f\u5728\u8655\u7406\u5927\u91cf\u6578\u64da\u6642\uff1a<\/p>\n<pre><code>SELECT * FROM users LIMIT 10;<\/code><\/pre>\n<h2 id=\"7-%e5%ae%9a%e6%9c%9f%e6%9b%b4%e6%96%b0%e7%b5%b1%e8%a8%88%e4%bf%a1%e6%81%af-cbDRdSoeWc\">7. \u5b9a\u671f\u66f4\u65b0\u7d71\u8a08\u4fe1\u606f<\/h2>\n<p>\u6578\u64da\u5eab\u7ba1\u7406\u7cfb\u7d71\u4f7f\u7528\u7d71\u8a08\u4fe1\u606f\u4f86\u512a\u5316\u67e5\u8a62\u8a08\u5283\u3002\u5b9a\u671f\u66f4\u65b0\u7d71\u8a08\u4fe1\u606f\u53ef\u4ee5\u5e6b\u52a9\u6578\u64da\u5eab\u9078\u64c7\u6700\u4f73\u7684\u67e5\u8a62\u57f7\u884c\u8a08\u5283\uff1a<\/p>\n<pre><code>ANALYZE TABLE users;<\/code><\/pre>\n<h2 id=\"8-%e4%bd%bf%e7%94%a8%e9%81%a9%e7%95%b6%e7%9a%84%e6%95%b8%e6%93%9a%e9%a1%9e%e5%9e%8b-cbDRdSoeWc\">8. \u4f7f\u7528\u9069\u7576\u7684\u6578\u64da\u985e\u578b<\/h2>\n<p>\u9078\u64c7\u5408\u9069\u7684\u6578\u64da\u985e\u578b\u53ef\u4ee5\u6e1b\u5c11\u5b58\u5132\u7a7a\u9593\u4e26\u63d0\u9ad8\u6027\u80fd\u3002\u4f8b\u5982\uff0c\u5c0d\u65bc\u5c0f\u7bc4\u570d\u7684\u6574\u6578\uff0c\u4f7f\u7528TINYINT\u800c\u4e0d\u662fINT\u53ef\u4ee5\u7bc0\u7701\u7a7a\u9593\uff1a<\/p>\n<pre><code>CREATE TABLE example (\n    id TINYINT,\n    name VARCHAR(100)\n);<\/code><\/pre>\n<h2 id=\"9-%e9%81%bf%e5%85%8d%e5%9c%a8%e6%9f%a5%e8%a9%a2%e4%b8%ad%e4%bd%bf%e7%94%a8%e5%87%bd%e6%95%b8-cbDRdSoeWc\">9. \u907f\u514d\u5728\u67e5\u8a62\u4e2d\u4f7f\u7528\u51fd\u6578<\/h2>\n<p>\u5728WHERE\u5b50\u53e5\u4e2d\u4f7f\u7528\u51fd\u6578\u6703\u5c0e\u81f4\u7d22\u5f15\u5931\u6548\uff0c\u5f9e\u800c\u5f71\u97ff\u6027\u80fd\u3002\u61c9\u8a72\u76e1\u91cf\u907f\u514d\u5728\u67e5\u8a62\u4e2d\u4f7f\u7528\u51fd\u6578\uff0c\u6216\u5c07\u5176\u79fb\u81f3\u5176\u4ed6\u5730\u65b9\u9032\u884c\u8655\u7406\u3002<\/p>\n<h2 id=\"10-%e6%b8%9b%e5%b0%91%e9%8e%96%e5%ae%9a-cbDRdSoeWc\">10. \u6e1b\u5c11\u9396\u5b9a<\/h2>\n<p>\u5728\u9ad8\u4f75\u767c\u74b0\u5883\u4e2d\uff0c\u9396\u5b9a\u6703\u5f71\u97ff\u6027\u80fd\u3002\u4f7f\u7528\u9069\u7576\u7684\u9694\u96e2\u7d1a\u5225\u548c\u9396\u5b9a\u7b56\u7565\u53ef\u4ee5\u6e1b\u5c11\u9396\u5b9a\u7684\u5f71\u97ff\uff0c\u5f9e\u800c\u63d0\u9ad8\u67e5\u8a62\u6027\u80fd\u3002<\/p>\n<h2 id=\"%e7%b8%bd%e7%b5%90-cbDRdSoeWc\">\u7e3d\u7d50<\/h2>\n<p>\u512a\u5316SQL\u8a9e\u53e5\u662f\u63d0\u9ad8\u6578\u64da\u5eab\u6027\u80fd\u7684\u95dc\u9375\u3002\u901a\u904e\u4ee5\u4e0a\u5341\u689d\u5efa\u8b70\uff0c\u60a8\u53ef\u4ee5\u6709\u6548\u5730\u63d0\u5347SQL\u67e5\u8a62\u7684\u901f\u5ea6\uff0c\u5f9e\u800c\u63d0\u9ad8\u6574\u9ad4\u7cfb\u7d71\u7684\u6548\u7387\u3002\u5982\u679c\u60a8\u6b63\u5728\u5c0b\u627e\u9ad8\u6548\u7684\u89e3\u6c7a\u65b9\u6848\u4f86\u652f\u6301\u60a8\u7684\u6578\u64da\u5eab\u9700\u6c42\uff0c\u8003\u616e\u4f7f\u7528<a href=\"https:\/\/server.hk\">\u9999\u6e2fVPS<\/a>\u6216<a href=\"https:\/\/server.hk\">\u9999\u6e2f\u4f3a\u670d\u5668<\/a>\uff0c\u4ee5\u7372\u5f97\u66f4\u597d\u7684\u6027\u80fd\u548c\u7a69\u5b9a\u6027\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u63d0\u5347SQL\u6027\u80fd\u7684\u5341\u689d\u5efa\u8b70\uff0c\u5e6b\u52a9\u4f60\u512a\u5316\u8a9e\u53e5\uff0c\u986f\u8457\u52a0\u5feb\u67e5\u8a62\u901f\u5ea6\uff0c\u8b93\u6578\u64da\u8655\u7406\u66f4\u9ad8\u6548\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-195157","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/195157","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=195157"}],"version-history":[{"count":1,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/195157\/revisions"}],"predecessor-version":[{"id":195158,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/195157\/revisions\/195158"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=195157"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=195157"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=195157"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}