{"id":152399,"date":"2024-11-01T22:41:25","date_gmt":"2024-11-01T14:41:25","guid":{"rendered":"https:\/\/server.hk\/cnblog\/152399\/"},"modified":"2024-11-01T22:41:26","modified_gmt":"2024-11-01T14:41:26","slug":"%e6%b8%ac%e8%a9%a6sql%e8%aa%9e%e5%8f%a5%e5%9f%b7%e8%a1%8c%e6%99%82%e9%96%93%e7%9a%84%e6%96%b9%e6%b3%95","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/152399\/","title":{"rendered":"\u6e2c\u8a66SQL\u8a9e\u53e5\u57f7\u884c\u6642\u9593\u7684\u65b9\u6cd5"},"content":{"rendered":"

\u6e2c\u8a66SQL\u8a9e\u53e5\u57f7\u884c\u6642\u9593\u7684\u65b9\u6cd5<\/h1>\n

\u5728\u6578\u64da\u5eab\u7ba1\u7406\u4e2d\uff0cSQL\u8a9e\u53e5\u7684\u57f7\u884c\u6548\u7387\u5c0d\u65bc\u7cfb\u7d71\u6027\u80fd\u81f3\u95dc\u91cd\u8981\u3002\u7121\u8ad6\u662f\u5927\u578b\u4f01\u696d\u9084\u662f\u5c0f\u578b\u61c9\u7528\uff0c\u512a\u5316SQL\u67e5\u8a62\u7684\u57f7\u884c\u6642\u9593\u90fd\u80fd\u986f\u8457\u63d0\u5347\u6574\u9ad4\u6027\u80fd\u3002\u672c\u6587\u5c07\u63a2\u8a0e\u5e7e\u7a2e\u6e2c\u8a66SQL\u8a9e\u53e5\u57f7\u884c\u6642\u9593\u7684\u65b9\u6cd5\uff0c\u5e6b\u52a9\u958b\u767c\u8005\u548c\u6578\u64da\u5eab\u7ba1\u7406\u54e1\u66f4\u6709\u6548\u5730\u9032\u884c\u6027\u80fd\u8abf\u512a\u3002<\/p>\n

1. \u4f7f\u7528EXPLAIN\u8a9e\u53e5<\/h2>\n

\u5728MySQL\u548cPostgreSQL\u7b49\u6578\u64da\u5eab\u4e2d\uff0cEXPLAIN<\/code>\u8a9e\u53e5\u662f\u4e00\u500b\u5f37\u5927\u7684\u5de5\u5177\uff0c\u53ef\u4ee5\u5e6b\u52a9\u958b\u767c\u8005\u4e86\u89e3\u67e5\u8a62\u7684\u57f7\u884c\u8a08\u5283\u3002\u901a\u904e\u5206\u6790\u57f7\u884c\u8a08\u5283\uff0c\u958b\u767c\u8005\u53ef\u4ee5\u8b58\u5225\u51fa\u6f5b\u5728\u7684\u6027\u80fd\u74f6\u9838\u3002<\/p>\n

EXPLAIN SELECT * FROM users WHERE age > 30;<\/code><\/pre>\n
\u57f7\u884c\u4e0a\u8ff0\u8a9e\u53e5\u5f8c\uff0c\u6578\u64da\u5eab\u5c07\u8fd4\u56de\u4e00\u500b\u8868\u683c\uff0c\u986f\u793a\u67e5\u8a62\u7684\u57f7\u884c\u6b65\u9a5f\uff0c\u5305\u62ec\u4f7f\u7528\u7684\u7d22\u5f15\u3001\u884c\u6578\u4f30\u7b97\u7b49\u4fe1\u606f\u3002\u9019\u4e9b\u4fe1\u606f\u53ef\u4ee5\u5e6b\u52a9\u958b\u767c\u8005\u512a\u5316\u67e5\u8a62\uff0c\u4f8b\u5982\u6dfb\u52a0\u7d22\u5f15\u6216\u91cd\u5beb\u67e5\u8a62\u8a9e\u53e5\u3002<\/p>\n
2. \u4f7f\u7528\u8a08\u6642\u5668<\/h2>\n
\u53e6\u4e00\u7a2e\u7c21\u55ae\u7684\u65b9\u6cd5\u662f\u4f7f\u7528\u8a08\u6642\u5668\u4f86\u6e2c\u91cfSQL\u8a9e\u53e5\u7684\u57f7\u884c\u6642\u9593\u3002\u5728\u8a31\u591a\u6578\u64da\u5eab\u7ba1\u7406\u7cfb\u7d71\u4e2d\uff0c\u53ef\u4ee5\u4f7f\u7528\u5167\u5efa\u7684\u8a08\u6642\u529f\u80fd\u4f86\u7372\u53d6\u57f7\u884c\u6642\u9593\u3002<\/p>\n
SET @start_time = NOW();\nSELECT * FROM orders WHERE order_date > '2023-01-01';\nSET @end_time = NOW();\nSELECT TIMEDIFF(@end_time, @start_time) AS execution_time;<\/code><\/pre>\n
\u9019\u6bb5\u4ee3\u78bc\u9996\u5148\u8a18\u9304\u958b\u59cb\u6642\u9593\uff0c\u7136\u5f8c\u57f7\u884c\u67e5\u8a62\uff0c\u6700\u5f8c\u8a08\u7b97\u4e26\u986f\u793a\u57f7\u884c\u6642\u9593\u3002\u9019\u7a2e\u65b9\u6cd5\u7c21\u55ae\u76f4\u63a5\uff0c\u9069\u5408\u5feb\u901f\u6e2c\u8a66\u3002<\/p>\n
3. \u4f7f\u7528\u6578\u64da\u5eab\u6027\u80fd\u76e3\u63a7\u5de5\u5177<\/h2>\n
\u8a31\u591a\u6578\u64da\u5eab\u7ba1\u7406\u7cfb\u7d71\u63d0\u4f9b\u4e86\u6027\u80fd\u76e3\u63a7\u5de5\u5177\uff0c\u53ef\u4ee5\u5be6\u6642\u8ddf\u8e2aSQL\u8a9e\u53e5\u7684\u57f7\u884c\u6642\u9593\u3002\u4f8b\u5982\uff0cMySQL\u7684Performance Schema\u548cPostgreSQL\u7684pg_stat_statements\u64f4\u5c55\u90fd\u80fd\u63d0\u4f9b\u8a73\u7d30\u7684\u57f7\u884c\u6642\u9593\u7d71\u8a08\u3002<\/p>\n
\u9019\u4e9b\u5de5\u5177\u901a\u5e38\u6703\u8a18\u9304\u6bcf\u500b\u67e5\u8a62\u7684\u57f7\u884c\u6642\u9593\u3001\u8abf\u7528\u6b21\u6578\u548c\u5e73\u5747\u57f7\u884c\u6642\u9593\u7b49\u4fe1\u606f\uff0c\u5e6b\u52a9\u958b\u767c\u8005\u8b58\u5225\u6700\u8017\u6642\u7684\u67e5\u8a62\u4e26\u9032\u884c\u512a\u5316\u3002<\/p>\n
4. \u4f7f\u7528\u61c9\u7528\u7a0b\u5f0f\u65e5\u8a8c<\/h2>\n
\u5728\u61c9\u7528\u7a0b\u5f0f\u5c64\u9762\uff0c\u958b\u767c\u8005\u53ef\u4ee5\u5728\u57f7\u884cSQL\u67e5\u8a62\u6642\u8a18\u9304\u65e5\u8a8c\uff0c\u9019\u6a23\u53ef\u4ee5\u5728\u61c9\u7528\u7a0b\u5f0f\u7684\u4e0a\u4e0b\u6587\u4e2d\u7372\u53d6\u57f7\u884c\u6642\u9593\u3002\u4ee5\u4e0b\u662f\u4e00\u500b\u4f7f\u7528Python\u7684\u7bc4\u4f8b\uff1a<\/p>\n
import time\nimport mysql.connector\n\nconnection = mysql.connector.connect(user='user', password='password', host='127.0.0.1', database='test_db')\ncursor = connection.cursor()\n\nstart_time = time.time()\ncursor.execute(\"SELECT * FROM products WHERE price < 100\")\nexecution_time = time.time() - start_time\n\nprint(f\"Query executed in {execution_time} seconds\")\ncursor.close()\nconnection.close()<\/code><\/pre>\n
\u9019\u6bb5\u4ee3\u78bc\u5728\u57f7\u884c\u67e5\u8a62\u524d\u5f8c\u8a18\u9304\u6642\u9593\uff0c\u4e26\u8a08\u7b97\u51fa\u67e5\u8a62\u7684\u57f7\u884c\u6642\u9593\uff0c\u65b9\u4fbf\u958b\u767c\u8005\u9032\u884c\u6027\u80fd\u5206\u6790\u3002<\/p>\n
5. \u4f7f\u7528SQL Server\u7684SET STATISTICS TIME<\/h2>\n
\u5728SQL Server\u4e2d\uff0c\u53ef\u4ee5\u4f7f\u7528SET STATISTICS TIME ON<\/code>\u4f86\u986f\u793a\u6bcf\u500b\u67e5\u8a62\u7684\u57f7\u884c\u6642\u9593\u3002\u9019\u5c0d\u65bc\u8abf\u8a66\u548c\u512a\u5316\u67e5\u8a62\u975e\u5e38\u6709\u5e6b\u52a9\u3002<\/p>\n
SET STATISTICS TIME ON;\nSELECT * FROM employees WHERE department = 'Sales';\nSET STATISTICS TIME OFF;<\/code><\/pre>\n
\u57f7\u884c\u4e0a\u8ff0\u8a9e\u53e5\u5f8c\uff0cSQL Server\u5c07\u5728\u6d88\u606f\u7a97\u53e3\u4e2d\u986f\u793a\u67e5\u8a62\u7684\u57f7\u884c\u6642\u9593\uff0c\u5e6b\u52a9\u958b\u767c\u8005\u5feb\u901f\u4e86\u89e3\u6027\u80fd\u72c0\u6cc1\u3002<\/p>\n
\u7e3d\u7d50<\/h2>\n
\u6e2c\u8a66SQL\u8a9e\u53e5\u7684\u57f7\u884c\u6642\u9593\u662f\u6578\u64da\u5eab\u6027\u80fd\u512a\u5316\u7684\u91cd\u8981\u6b65\u9a5f\u3002\u901a\u904e\u4f7f\u7528EXPLAIN<\/code>\u8a9e\u53e5\u3001\u8a08\u6642\u5668\u3001\u6027\u80fd\u76e3\u63a7\u5de5\u5177\u3001\u61c9\u7528\u7a0b\u5f0f\u65e5\u8a8c\u4ee5\u53caSQL Server\u7684\u7d71\u8a08\u529f\u80fd\uff0c\u958b\u767c\u8005\u53ef\u4ee5\u6709\u6548\u5730\u8b58\u5225\u548c\u89e3\u6c7a\u6027\u80fd\u554f\u984c\u3002\u9019\u4e9b\u65b9\u6cd5\u4e0d\u50c5\u80fd\u63d0\u9ad8\u67e5\u8a62\u6548\u7387\uff0c\u9084\u80fd\u6539\u5584\u6574\u9ad4\u7cfb\u7d71\u6027\u80fd\u3002<\/p>\n
\u5982\u679c\u60a8\u6b63\u5728\u5c0b\u627e\u9ad8\u6548\u7684\u9999\u6e2fVPS<\/a>\u89e3\u6c7a\u65b9\u6848\uff0cServer.HK\u63d0\u4f9b\u591a\u7a2e\u9078\u64c7\uff0c\u5e6b\u52a9\u60a8\u512a\u5316\u6578\u64da\u5eab\u6027\u80fd\uff0c\u63d0\u5347\u696d\u52d9\u6548\u7387\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"
\u4e86\u89e3\u5982\u4f55\u6e2c\u8a66SQL\u8a9e\u53e5\u7684\u57f7\u884c\u6642\u9593\uff0c\u63d0\u5347\u67e5\u8a62\u6548\u80fd\uff0c\u512a\u5316\u6578\u64da\u5eab\u64cd\u4f5c\uff0c\u78ba\u4fdd\u7cfb\u7d71\u9ad8\u6548\u904b\u884c\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-152399","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/152399","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=152399"}],"version-history":[{"count":1,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/152399\/revisions"}],"predecessor-version":[{"id":152400,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/152399\/revisions\/152400"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=152399"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=152399"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=152399"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}