{"id":168753,"date":"2024-11-06T15:52:17","date_gmt":"2024-11-06T07:52:17","guid":{"rendered":"https:\/\/server.hk\/cnblog\/168753\/"},"modified":"2024-11-06T15:52:18","modified_gmt":"2024-11-06T07:52:18","slug":"top-%e5%ad%97%e5%8f%a5%e5%8a%a0-sql-%e8%ae%8a%e9%87%8f%e7%9a%84%e7%9b%b8%e9%97%9c%e5%95%8f%e9%a1%8c","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/168753\/","title":{"rendered":"TOP \u5b57\u53e5\u52a0 SQL \u8b8a\u91cf\u7684\u76f8\u95dc\u554f\u984c"},"content":{"rendered":"

TOP \u5b57\u53e5\u52a0 SQL \u8b8a\u91cf\u7684\u76f8\u95dc\u554f\u984c<\/h1>\n

\u5728\u73fe\u4eca\u7684\u6578\u64da\u9a45\u52d5\u6642\u4ee3\uff0cSQL\uff08\u7d50\u69cb\u5316\u67e5\u8a62\u8a9e\u8a00\uff09\u662f\u7528\u65bc\u7ba1\u7406\u548c\u64cd\u4f5c\u6578\u64da\u5eab\u7684\u4e3b\u8981\u5de5\u5177\u4e4b\u4e00\u3002\u96a8\u8457\u61c9\u7528\u7a0b\u5e8f\u7684\u8907\u96dc\u6027\u589e\u52a0\uff0c\u958b\u767c\u8005\u7d93\u5e38\u9700\u8981\u5728 SQL \u67e5\u8a62\u4e2d\u4f7f\u7528\u8b8a\u91cf\u4f86\u63d0\u9ad8\u9748\u6d3b\u6027\u548c\u53ef\u8b80\u6027\u3002\u7136\u800c\uff0c\u4f7f\u7528 SQL \u8b8a\u91cf\u6642\uff0c\u958b\u767c\u8005\u53ef\u80fd\u6703\u9047\u5230\u4e00\u4e9b\u5e38\u898b\u7684\u554f\u984c\u548c\u6311\u6230\u3002\u672c\u6587\u5c07\u63a2\u8a0e\u9019\u4e9b\u554f\u984c\u53ca\u5176\u89e3\u6c7a\u65b9\u6848\u3002<\/p>\n

SQL \u8b8a\u91cf\u7684\u57fa\u672c\u6982\u5ff5<\/h2>\n

SQL \u8b8a\u91cf\u662f\u7528\u65bc\u5b58\u5132\u6578\u64da\u7684\u547d\u540d\u4f4d\u7f6e\uff0c\u53ef\u4ee5\u5728 SQL \u67e5\u8a62\u4e2d\u91cd\u8907\u4f7f\u7528\u3002\u8b8a\u91cf\u7684\u4f7f\u7528\u53ef\u4ee5\u4f7f\u67e5\u8a62\u66f4\u5177\u53ef\u8b80\u6027\uff0c\u4e26\u6e1b\u5c11\u91cd\u8907\u4ee3\u78bc\u3002\u4f8b\u5982\uff0c\u5728 MySQL \u4e2d\uff0c\u53ef\u4ee5\u4f7f\u7528\u4ee5\u4e0b\u8a9e\u6cd5\u4f86\u5b9a\u7fa9\u548c\u4f7f\u7528\u8b8a\u91cf\uff1a<\/p>\n

SET @myVariable = 'Hello, World!';\nSELECT @myVariable;<\/code><\/pre>\n
\u5728\u9019\u500b\u4f8b\u5b50\u4e2d\uff0c\u6211\u5011\u5b9a\u7fa9\u4e86\u4e00\u500b\u540d\u70ba @myVariable<\/code> \u7684\u8b8a\u91cf\uff0c\u4e26\u5c07\u5176\u503c\u8a2d\u7f6e\u70ba ‘Hello, World!’\u3002\u7136\u5f8c\uff0c\u6211\u5011\u53ef\u4ee5\u5728\u5f8c\u7e8c\u7684\u67e5\u8a62\u4e2d\u4f7f\u7528\u9019\u500b\u8b8a\u91cf\u3002<\/p>\n
\u5e38\u898b\u554f\u984c\u53ca\u89e3\u6c7a\u65b9\u6848<\/h2>\n
1. \u8b8a\u91cf\u4f5c\u7528\u57df\u554f\u984c<\/h3>\n
\u5728 SQL \u4e2d\uff0c\u8b8a\u91cf\u7684\u4f5c\u7528\u57df\u53ef\u80fd\u6703\u5c0e\u81f4\u4e00\u4e9b\u56f0\u60d1\u3002\u7279\u5225\u662f\u5728\u5b58\u5132\u904e\u7a0b\u6216\u89f8\u767c\u5668\u4e2d\uff0c\u5c40\u90e8\u8b8a\u91cf\u548c\u5168\u5c40\u8b8a\u91cf\u7684\u4f7f\u7528\u53ef\u80fd\u6703\u5f15\u8d77\u6df7\u6dc6\u3002\u5c40\u90e8\u8b8a\u91cf\u53ea\u80fd\u5728\u5176\u5b9a\u7fa9\u7684\u7bc4\u570d\u5167\u4f7f\u7528\uff0c\u800c\u5168\u5c40\u8b8a\u91cf\u5247\u53ef\u4ee5\u5728\u6574\u500b\u6703\u8a71\u4e2d\u4f7f\u7528\u3002<\/p>\n
\u89e3\u6c7a\u65b9\u6848\u662f\u660e\u78ba\u5340\u5206\u8b8a\u91cf\u7684\u4f5c\u7528\u57df\uff0c\u4e26\u5728\u9700\u8981\u6642\u4f7f\u7528\u9069\u7576\u7684\u8b8a\u91cf\u3002\u4f8b\u5982\uff0c\u5728\u5b58\u5132\u904e\u7a0b\u4e2d\u4f7f\u7528\u5c40\u90e8\u8b8a\u91cf\u6642\uff0c\u61c9\u4f7f\u7528 DECLARE<\/code> \u8a9e\u53e5\u4f86\u5b9a\u7fa9\u8b8a\u91cf\uff1a<\/p>\n
CREATE PROCEDURE myProcedure()\nBEGIN\n    DECLARE myLocalVar INT;\n    SET myLocalVar = 10;\n    SELECT myLocalVar;\nEND;<\/code><\/pre>\n
2. \u8b8a\u91cf\u985e\u578b\u4e0d\u5339\u914d<\/h3>\n
\u5728\u4f7f\u7528\u8b8a\u91cf\u6642\uff0c\u985e\u578b\u4e0d\u5339\u914d\u662f\u4e00\u500b\u5e38\u898b\u554f\u984c\u3002\u4f8b\u5982\uff0c\u5c07\u5b57\u7b26\u4e32\u8b8a\u91cf\u8207\u6574\u6578\u9032\u884c\u6bd4\u8f03\u53ef\u80fd\u6703\u5c0e\u81f4\u932f\u8aa4\u6216\u4e0d\u6b63\u78ba\u7684\u7d50\u679c\u3002\u70ba\u4e86\u907f\u514d\u9019\u7a2e\u60c5\u6cc1\uff0c\u958b\u767c\u8005\u61c9\u8a72\u78ba\u4fdd\u8b8a\u91cf\u7684\u985e\u578b\u8207\u5176\u4f7f\u7528\u7684\u4e0a\u4e0b\u6587\u76f8\u7b26\u3002<\/p>\n
\u4f8b\u5982\uff0c\u7576\u4f7f\u7528\u8b8a\u91cf\u9032\u884c\u6578\u5b78\u904b\u7b97\u6642\uff0c\u61c9\u78ba\u4fdd\u8b8a\u91cf\u7684\u985e\u578b\u70ba\u6578\u5b57\uff1a<\/p>\n
SET @num1 = 5;\nSET @num2 = '10'; -- \u5b57\u7b26\u4e32\u985e\u578b\nSELECT @num1 + CAST(@num2 AS UNSIGNED); -- \u4f7f\u7528 CAST \u8f49\u63db\u985e\u578b<\/code><\/pre>\n
3. SQL \u6ce8\u5165\u98a8\u96aa<\/h3>\n
\u4f7f\u7528\u8b8a\u91cf\u6642\uff0cSQL \u6ce8\u5165\u662f\u4e00\u500b\u6f5b\u5728\u7684\u5b89\u5168\u98a8\u96aa\u3002\u7576\u8b8a\u91cf\u7684\u503c\u4f86\u81ea\u7528\u6236\u8f38\u5165\u6642\uff0c\u672a\u7d93\u904e\u6ffe\u7684\u6578\u64da\u53ef\u80fd\u6703\u5c0e\u81f4\u60e1\u610f\u4ee3\u78bc\u7684\u57f7\u884c\u3002\u70ba\u4e86\u9632\u6b62 SQL \u6ce8\u5165\uff0c\u958b\u767c\u8005\u61c9\u8a72\u59cb\u7d42\u5c0d\u7528\u6236\u8f38\u5165\u9032\u884c\u9a57\u8b49\u548c\u904e\u6ffe\u3002<\/p>\n
\u4f8b\u5982\uff0c\u4f7f\u7528\u9810\u8655\u7406\u8a9e\u53e5\u53ef\u4ee5\u6709\u6548\u9632\u6b62 SQL \u6ce8\u5165\uff1a<\/p>\n
PREPARE stmt FROM 'SELECT * FROM users WHERE username = ?';\nSET @username = 'user_input';\nEXECUTE stmt USING @username;<\/code><\/pre>\n
\u7d50\u8ad6<\/h2>\n
\u5728\u4f7f\u7528 SQL \u8b8a\u91cf\u6642\uff0c\u958b\u767c\u8005\u9700\u8981\u6ce8\u610f\u8b8a\u91cf\u7684\u4f5c\u7528\u57df\u3001\u985e\u578b\u5339\u914d\u4ee5\u53ca\u5b89\u5168\u6027\u7b49\u554f\u984c\u3002\u901a\u904e\u6b63\u78ba\u7684\u4f7f\u7528\u65b9\u6cd5\u548c\u6700\u4f73\u5be6\u8e10\uff0c\u53ef\u4ee5\u6709\u6548\u5730\u63d0\u9ad8 SQL \u67e5\u8a62\u7684\u9748\u6d3b\u6027\u548c\u5b89\u5168\u6027\u3002\u5c0d\u65bc\u9700\u8981\u9ad8\u6548\u6578\u64da\u7ba1\u7406\u7684\u4f01\u696d\u4f86\u8aaa\uff0c\u9078\u64c7\u5408\u9069\u7684 VPS<\/a> \u89e3\u6c7a\u65b9\u6848\u4e5f\u662f\u81f3\u95dc\u91cd\u8981\u7684\uff0c\u9019\u6a23\u53ef\u4ee5\u78ba\u4fdd\u6578\u64da\u5eab\u7684\u7a69\u5b9a\u6027\u548c\u5b89\u5168\u6027\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"
\u63a2\u7d22 TOP \u5b57\u53e5\u8207 SQL \u8b8a\u91cf\u7684\u5e38\u898b\u554f\u984c\uff0c\u4e86\u89e3\u5982\u4f55\u6709\u6548\u4f7f\u7528\u9019\u4e9b\u529f\u80fd\u63d0\u5347\u67e5\u8a62\u6548\u7387\u8207\u9748\u6d3b\u6027\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-168753","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/168753","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=168753"}],"version-history":[{"count":1,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/168753\/revisions"}],"predecessor-version":[{"id":168754,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/168753\/revisions\/168754"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=168753"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=168753"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=168753"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}