{"id":168423,"date":"2024-11-06T12:15:17","date_gmt":"2024-11-06T04:15:17","guid":{"rendered":"https:\/\/server.hk\/cnblog\/168423\/"},"modified":"2024-11-06T12:15:18","modified_gmt":"2024-11-06T04:15:18","slug":"sql-%e5%84%aa%e5%8c%96%ef%bc%8c%e6%80%8e%e9%ba%bc%e5%81%9a%ef%bc%9f","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/168423\/","title":{"rendered":"SQL \u512a\u5316\uff0c\u600e\u9ebc\u505a\uff1f"},"content":{"rendered":"

SQL \u512a\u5316\uff0c\u600e\u9ebc\u505a\uff1f<\/h1>\n

\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\u9032\u884c\u4ea4\u4e92\u7684\u4e3b\u8981\u5de5\u5177\u3002\u96a8\u8457\u6578\u64da\u91cf\u7684\u589e\u9577\uff0c\u5982\u4f55\u6709\u6548\u5730\u512a\u5316SQL\u67e5\u8a62\u6210\u70ba\u4e86\u958b\u767c\u8005\u548c\u6578\u64da\u5eab\u7ba1\u7406\u54e1\u9762\u81e8\u7684\u4e00\u5927\u6311\u6230\u3002\u672c\u6587\u5c07\u63a2\u8a0e\u4e00\u4e9b\u5e38\u898b\u7684SQL\u512a\u5316\u6280\u8853\uff0c\u5e6b\u52a9\u60a8\u63d0\u9ad8\u67e5\u8a62\u6027\u80fd\u3002<\/p>\n

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

\u7d22\u5f15\u662f\u63d0\u9ad8\u67e5\u8a62\u6027\u80fd\u7684\u6700\u6709\u6548\u65b9\u6cd5\u4e4b\u4e00\u3002\u901a\u904e\u5728\u8868\u7684\u67d0\u4e9b\u5217\u4e0a\u5275\u5efa\u7d22\u5f15\uff0c\u6578\u64da\u5eab\u53ef\u4ee5\u66f4\u5feb\u5730\u67e5\u627e\u548c\u6aa2\u7d22\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 (column1, column2, ...);<\/code><\/pre>\n
\u7136\u800c\uff0c\u904e\u591a\u7684\u7d22\u5f15\u6703\u5f71\u97ff\u6578\u64da\u7684\u63d2\u5165\u548c\u66f4\u65b0\u6027\u80fd\uff0c\u56e0\u6b64\u61c9\u6839\u64da\u5be6\u969b\u9700\u6c42\u8b39\u614e\u9078\u64c7\u7d22\u5f15\u3002<\/p>\n
2. \u907f\u514d\u4f7f\u7528SELECT *<\/h2>\n
\u4f7f\u7528SELECT *\u6703\u5c0e\u81f4\u6578\u64da\u5eab\u8fd4\u56de\u6240\u6709\u5217\uff0c\u9019\u5728\u67d0\u4e9b\u60c5\u6cc1\u4e0b\u6703\u6d6a\u8cbb\u8cc7\u6e90\u3002\u61c9\u8a72\u660e\u78ba\u6307\u5b9a\u9700\u8981\u7684\u5217\uff0c\u4ee5\u6e1b\u5c11\u6578\u64da\u50b3\u8f38\u91cf\u3002\u4f8b\u5982\uff1a<\/p>\n
SELECT column1, column2 FROM table_name WHERE condition;<\/code><\/pre>\n
3. \u4f7f\u7528JOIN\u800c\u975e\u5b50\u67e5\u8a62<\/h2>\n
\u5728\u8a31\u591a\u60c5\u6cc1\u4e0b\uff0c\u4f7f\u7528JOIN\u64cd\u4f5c\u6bd4\u4f7f\u7528\u5b50\u67e5\u8a62\u66f4\u9ad8\u6548\u3002JOIN\u53ef\u4ee5\u5728\u55ae\u500b\u67e5\u8a62\u4e2d\u5408\u4f75\u591a\u500b\u8868\u7684\u6578\u64da\uff0c\u800c\u5b50\u67e5\u8a62\u5247\u9700\u8981\u591a\u6b21\u67e5\u8a62\u6578\u64da\u5eab\u3002\u4ee5\u4e0b\u662fJOIN\u7684\u57fa\u672c\u7528\u6cd5\uff1a<\/p>\n
SELECT a.column1, b.column2 \nFROM table_a a \nJOIN table_b b ON a.common_column = b.common_column;<\/code><\/pre>\n
4. \u512a\u5316WHERE\u5b50\u53e5<\/h2>\n
\u5728WHERE\u5b50\u53e5\u4e2d\u4f7f\u7528\u9069\u7576\u7684\u689d\u4ef6\u53ef\u4ee5\u986f\u8457\u63d0\u9ad8\u67e5\u8a62\u6027\u80fd\u3002\u61c9\u907f\u514d\u5728WHERE\u5b50\u53e5\u4e2d\u4f7f\u7528\u51fd\u6578\uff0c\u56e0\u70ba\u9019\u6703\u5c0e\u81f4\u5168\u8868\u6383\u63cf\u3002\u76f8\u53cd\uff0c\u61c9\u8a72\u4f7f\u7528\u7d22\u5f15\u5217\u9032\u884c\u6bd4\u8f03\u3002\u4f8b\u5982\uff1a<\/p>\n
SELECT * FROM table_name WHERE indexed_column = 'value';<\/code><\/pre>\n
5. \u4f7f\u7528LIMIT\u9650\u5236\u7d50\u679c\u96c6<\/h2>\n
\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\u578b\u6578\u64da\u96c6\u6642\u3002\u4f8b\u5982\uff1a<\/p>\n
SELECT * FROM table_name LIMIT 10;<\/code><\/pre>\n
6. \u5b9a\u671f\u7dad\u8b77\u6578\u64da\u5eab<\/h2>\n
\u5b9a\u671f\u9032\u884c\u6578\u64da\u5eab\u7dad\u8b77\uff0c\u5982\u91cd\u5efa\u7d22\u5f15\u548c\u66f4\u65b0\u7d71\u8a08\u4fe1\u606f\uff0c\u53ef\u4ee5\u5e6b\u52a9\u4fdd\u6301\u6578\u64da\u5eab\u7684\u6027\u80fd\u3002\u9019\u4e9b\u64cd\u4f5c\u53ef\u4ee5\u6e05\u7406\u788e\u7247\u4e26\u78ba\u4fdd\u67e5\u8a62\u8a08\u5283\u7684\u6709\u6548\u6027\u3002<\/p>\n
7. \u4f7f\u7528\u67e5\u8a62\u5206\u6790\u5de5\u5177<\/h2>\n
\u8a31\u591a\u6578\u64da\u5eab\u7ba1\u7406\u7cfb\u7d71\u63d0\u4f9b\u67e5\u8a62\u5206\u6790\u5de5\u5177\uff0c\u53ef\u4ee5\u5e6b\u52a9\u8b58\u5225\u6027\u80fd\u74f6\u9838\u3002\u901a\u904e\u9019\u4e9b\u5de5\u5177\uff0c\u60a8\u53ef\u4ee5\u67e5\u770b\u67e5\u8a62\u7684\u57f7\u884c\u8a08\u5283\uff0c\u4e26\u627e\u51fa\u9700\u8981\u512a\u5316\u7684\u90e8\u5206\u3002<\/p>\n
\u7e3d\u7d50<\/h2>\n
SQL\u512a\u5316\u662f\u4e00\u500b\u6301\u7e8c\u7684\u904e\u7a0b\uff0c\u6d89\u53ca\u591a\u7a2e\u6280\u8853\u548c\u7b56\u7565\u3002\u901a\u904e\u5408\u7406\u4f7f\u7528\u7d22\u5f15\u3001\u907f\u514d\u4e0d\u5fc5\u8981\u7684\u67e5\u8a62\u3001\u512a\u5316WHERE\u5b50\u53e5\u7b49\u65b9\u6cd5\uff0c\u53ef\u4ee5\u986f\u8457\u63d0\u9ad8\u67e5\u8a62\u6027\u80fd\u3002\u5c0d\u65bc\u9700\u8981\u9ad8\u6548\u6578\u64da\u8655\u7406\u7684\u61c9\u7528\uff0c\u9078\u64c7\u5408\u9069\u7684 VPS<\/a> \u6216 \u9999\u6e2f\u4f3a\u670d\u5668<\/a> \u4e5f\u662f\u81f3\u95dc\u91cd\u8981\u7684\u3002\u4e86\u89e3\u548c\u5be6\u65bd\u9019\u4e9b\u512a\u5316\u6280\u8853\uff0c\u5c07\u6709\u52a9\u65bc\u63d0\u5347\u60a8\u7684\u6578\u64da\u5eab\u6027\u80fd\uff0c\u5f9e\u800c\u66f4\u597d\u5730\u652f\u6301\u696d\u52d9\u9700\u6c42\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"
\u4e86\u89e3SQL\u512a\u5316\u7684\u6280\u5de7\u8207\u65b9\u6cd5\uff0c\u63d0\u9ad8\u67e5\u8a62\u6548\u7387\uff0c\u6e1b\u5c11\u8cc7\u6e90\u6d88\u8017\uff0c\u63d0\u5347\u6578\u64da\u5eab\u6027\u80fd\uff0c\u5be6\u73fe\u66f4\u5feb\u7684\u6578\u64da\u8655\u7406\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-168423","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/168423","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=168423"}],"version-history":[{"count":1,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/168423\/revisions"}],"predecessor-version":[{"id":168424,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/168423\/revisions\/168424"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=168423"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=168423"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=168423"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}