{"id":168465,"date":"2024-11-06T12:36:23","date_gmt":"2024-11-06T04:36:23","guid":{"rendered":"https:\/\/server.hk\/cnblog\/168465\/"},"modified":"2024-11-06T12:36:24","modified_gmt":"2024-11-06T04:36:24","slug":"sql-%e8%aa%9e%e5%8f%a5%e5%84%aa%e5%8c%96%e6%b3%a8%e6%84%8f","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/168465\/","title":{"rendered":"SQL \u8a9e\u53e5\u512a\u5316\u6ce8\u610f"},"content":{"rendered":"

SQL \u8a9e\u53e5\u512a\u5316\u6ce8\u610f<\/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\u512a\u5316 SQL \u8a9e\u53e5\u8b8a\u5f97\u8d8a\u4f86\u8d8a\u91cd\u8981\u3002\u512a\u5316\u4e0d\u50c5\u80fd\u63d0\u9ad8\u67e5\u8a62\u6027\u80fd\uff0c\u9084\u80fd\u6e1b\u5c11\u8cc7\u6e90\u6d88\u8017\uff0c\u5f9e\u800c\u63d0\u5347\u6574\u9ad4\u7cfb\u7d71\u7684\u6548\u7387\u3002\u672c\u6587\u5c07\u63a2\u8a0e SQL \u8a9e\u53e5\u512a\u5316\u7684\u5e7e\u500b\u95dc\u9375\u6ce8\u610f\u4e8b\u9805\u3002<\/p>\n

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

\u7d22\u5f15\u662f\u63d0\u9ad8\u67e5\u8a62\u6027\u80fd\u7684\u6709\u6548\u5de5\u5177\u3002\u901a\u904e\u5728\u8868\u7684\u67d0\u4e9b\u5217\u4e0a\u5275\u5efa\u7d22\u5f15\uff0c\u53ef\u4ee5\u52a0\u901f\u67e5\u8a62\u7684\u57f7\u884c\u901f\u5ea6\u3002\u7576\u67e5\u8a62\u6d89\u53ca\u5230 WHERE \u5b50\u53e5\u3001JOIN \u64cd\u4f5c\u6216 ORDER BY \u6642\uff0c\u7d22\u5f15\u7684\u4f5c\u7528\u5c24\u70ba\u660e\u986f\u3002<\/p>\n

CREATE INDEX idx_column_name ON table_name (column_name);<\/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\u5728\u5275\u5efa\u7d22\u5f15\u6642\u9700\u8981\u8b39\u614e\u8003\u91cf\u3002<\/p>\n
2. \u907f\u514d SELECT *<\/h2>\n
\u4f7f\u7528 SELECT * \u6703\u5c0e\u81f4\u67e5\u8a62\u8fd4\u56de\u8868\u4e2d\u7684\u6240\u6709\u5217\uff0c\u9019\u5728\u6578\u64da\u91cf\u5927\u6642\u6703\u6d6a\u8cbb\u5927\u91cf\u8cc7\u6e90\u3002\u61c9\u8a72\u660e\u78ba\u6307\u5b9a\u9700\u8981\u7684\u5217\uff0c\u4ee5\u6e1b\u5c11\u6578\u64da\u50b3\u8f38\u91cf\u548c\u8655\u7406\u6642\u9593\u3002<\/p>\n
SELECT column1, column2 FROM table_name WHERE condition;<\/code><\/pre>\n
3. \u4f7f\u7528\u5408\u9069\u7684 JOIN \u985e\u578b<\/h2>\n
\u5728\u9032\u884c\u591a\u8868\u67e5\u8a62\u6642\uff0c\u9078\u64c7\u5408\u9069\u7684 JOIN \u985e\u578b\u81f3\u95dc\u91cd\u8981\u3002INNER JOIN\u3001LEFT JOIN \u548c RIGHT JOIN \u7684\u6027\u80fd\u5dee\u7570\u53ef\u80fd\u6703\u5f71\u97ff\u67e5\u8a62\u7684\u57f7\u884c\u6642\u9593\u3002\u901a\u5e38\uff0cINNER JOIN \u7684\u6027\u80fd\u8f03\u597d\uff0c\u56e0\u70ba\u5b83\u53ea\u8fd4\u56de\u5339\u914d\u7684\u884c\u3002<\/p>\n
SELECT a.column1, b.column2 \nFROM table_a a \nINNER JOIN table_b b ON a.id = b.a_id;<\/code><\/pre>\n
4. \u9069\u7576\u4f7f\u7528 WHERE \u5b50\u53e5<\/h2>\n
WHERE \u5b50\u53e5\u7528\u65bc\u904e\u6ffe\u6578\u64da\uff0c\u61c9\u8a72\u76e1\u91cf\u4f7f\u7528\u80fd\u5920\u5229\u7528\u7d22\u5f15\u7684\u689d\u4ef6\u3002\u907f\u514d\u5728 WHERE \u5b50\u53e5\u4e2d\u4f7f\u7528\u51fd\u6578\u6216\u8a08\u7b97\uff0c\u56e0\u70ba\u9019\u6a23\u6703\u5c0e\u81f4\u7d22\u5f15\u5931\u6548\u3002<\/p>\n
SELECT * FROM table_name WHERE indexed_column = 'value';<\/code><\/pre>\n
5. \u4f7f\u7528 LIMIT \u9650\u5236\u7d50\u679c\u96c6<\/h2>\n
\u5728\u67e5\u8a62\u4e2d\u4f7f\u7528 LIMIT \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\u6578\u64da\u96c6\u6642\u3002<\/p>\n
SELECT * FROM table_name LIMIT 10;<\/code><\/pre>\n
6. \u5b9a\u671f\u5206\u6790\u548c\u91cd\u5efa\u7d22\u5f15<\/h2>\n
\u96a8\u8457\u6578\u64da\u7684\u589e\u9577\u548c\u8b8a\u66f4\uff0c\u7d22\u5f15\u53ef\u80fd\u6703\u8b8a\u5f97\u4e0d\u518d\u9ad8\u6548\u3002\u5b9a\u671f\u5206\u6790\u548c\u91cd\u5efa\u7d22\u5f15\u53ef\u4ee5\u5e6b\u52a9\u4fdd\u6301\u67e5\u8a62\u6027\u80fd\u3002\u5927\u591a\u6578\u6578\u64da\u5eab\u7ba1\u7406\u7cfb\u7d71\u90fd\u63d0\u4f9b\u4e86\u76f8\u95dc\u7684\u5de5\u5177\u548c\u547d\u4ee4\u4f86\u57f7\u884c\u9019\u4e9b\u64cd\u4f5c\u3002<\/p>\n
ANALYZE TABLE table_name;<\/code><\/pre>\n
7. \u4f7f\u7528\u9810\u7de8\u8b6f\u8a9e\u53e5<\/h2>\n
\u9810\u7de8\u8b6f\u8a9e\u53e5\u53ef\u4ee5\u63d0\u9ad8\u67e5\u8a62\u6027\u80fd\uff0c\u56e0\u70ba\u5b83\u5011\u5728\u7b2c\u4e00\u6b21\u57f7\u884c\u6642\u88ab\u7de8\u8b6f\u4e26\u5b58\u5132\uff0c\u5f8c\u7e8c\u7684\u57f7\u884c\u53ea\u9700\u50b3\u905e\u53c3\u6578\u5373\u53ef\u3002\u9019\u4e0d\u50c5\u63d0\u9ad8\u4e86\u6027\u80fd\uff0c\u9084\u589e\u5f37\u4e86\u5b89\u5168\u6027\uff0c\u56e0\u70ba\u5b83\u53ef\u4ee5\u9632\u6b62 SQL \u6ce8\u5165\u653b\u64ca\u3002<\/p>\n
PREPARE stmt FROM 'SELECT * FROM table_name WHERE column_name = ?';<\/code><\/pre>\n
\u7e3d\u7d50<\/h2>\n
SQL \u8a9e\u53e5\u7684\u512a\u5316\u662f\u4e00\u500b\u6301\u7e8c\u7684\u904e\u7a0b\uff0c\u6d89\u53ca\u591a\u65b9\u9762\u7684\u8003\u91cf\u3002\u901a\u904e\u5408\u7406\u4f7f\u7528\u7d22\u5f15\u3001\u907f\u514d\u4e0d\u5fc5\u8981\u7684\u67e5\u8a62\u3001\u9078\u64c7\u5408\u9069\u7684 JOIN \u985e\u578b\u4ee5\u53ca\u5b9a\u671f\u7dad\u8b77\u6578\u64da\u5eab\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 \u9999\u6e2f VPS<\/a> \u6216 \u96f2\u4f3a\u670d\u5668<\/a> \u4e5f\u662f\u81f3\u95dc\u91cd\u8981\u7684\uff0c\u9019\u6a23\u53ef\u4ee5\u78ba\u4fdd\u5728\u9ad8\u8ca0\u8f09\u60c5\u6cc1\u4e0b\u4ecd\u80fd\u4fdd\u6301\u826f\u597d\u7684\u6027\u80fd\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"
\u4e86\u89e3 SQL \u8a9e\u53e5\u512a\u5316\u7684\u95dc\u9375\u6ce8\u610f\u4e8b\u9805\uff0c\u63d0\u5347\u67e5\u8a62\u6548\u7387\uff0c\u6e1b\u5c11\u57f7\u884c\u6642\u9593\uff0c\u78ba\u4fdd\u8cc7\u6599\u5eab\u6027\u80fd\u6700\u4f73\u5316\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-168465","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/168465","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=168465"}],"version-history":[{"count":1,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/168465\/revisions"}],"predecessor-version":[{"id":168466,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/168465\/revisions\/168466"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=168465"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=168465"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=168465"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}