{"id":59541,"date":"2024-10-12T22:48:18","date_gmt":"2024-10-12T14:48:18","guid":{"rendered":"https:\/\/server.hk\/cnblog\/59541\/"},"modified":"2024-10-12T22:48:18","modified_gmt":"2024-10-12T14:48:18","slug":"cassandra%e6%9f%a5%e8%a9%a2%e8%aa%9e%e5%8f%a5cql%e7%9a%84%e5%b0%8f%e6%8a%80%e5%b7%a7","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/59541\/","title":{"rendered":"Cassandra\u67e5\u8a62\u8a9e\u53e5CQL\u7684\u5c0f\u6280\u5de7"},"content":{"rendered":"

Cassandra\u67e5\u8a62\u8a9e\u53e5CQL\u7684\u5c0f\u6280\u5de7<\/h1>\n

Apache Cassandra\u662f\u4e00\u500b\u9ad8\u6548\u80fd\u7684\u5206\u6563\u5f0f\u8cc7\u6599\u5eab\u7cfb\u7d71\uff0c\u5ee3\u6cdb\u61c9\u7528\u65bc\u9700\u8981\u9ad8\u53ef\u7528\u6027\u548c\u53ef\u64f4\u5c55\u6027\u7684\u5834\u666f\u3002Cassandra\u4f7f\u7528CQL\uff08Cassandra Query Language\uff09\u4f5c\u70ba\u5176\u67e5\u8a62\u8a9e\u8a00\uff0c\u9019\u4f7f\u5f97\u8cc7\u6599\u7684\u64cd\u4f5c\u8b8a\u5f97\u66f4\u52a0\u76f4\u89c0\u3002\u672c\u6587\u5c07\u4ecb\u7d39\u4e00\u4e9bCQL\u7684\u5c0f\u6280\u5de7\uff0c\u5e6b\u52a9\u4f7f\u7528\u8005\u66f4\u6709\u6548\u5730\u9032\u884c\u8cc7\u6599\u67e5\u8a62\u548c\u7ba1\u7406\u3002<\/p>\n

1. \u4f7f\u7528PRIMARY KEY\u7684\u8a2d\u8a08<\/h2>\n

\u5728Cassandra\u4e2d\uff0cPRIMARY KEY\u7684\u8a2d\u8a08\u81f3\u95dc\u91cd\u8981\u3002PRIMARY KEY\u7531Partition Key\u548cClustering Columns\u7d44\u6210\u3002Partition Key\u6c7a\u5b9a\u4e86\u8cc7\u6599\u7684\u5206\u4f48\uff0c\u800cClustering Columns\u5247\u6c7a\u5b9a\u4e86\u8cc7\u6599\u5728Partition\u5167\u7684\u6392\u5e8f\u3002\u5408\u7406\u7684\u8a2d\u8a08\u53ef\u4ee5\u63d0\u9ad8\u67e5\u8a62\u6548\u7387\u3002<\/p>\n

CREATE TABLE users (\n    user_id UUID PRIMARY KEY,\n    name TEXT,\n    email TEXT,\n    created_at TIMESTAMP\n);\n<\/code><\/pre>\n
\u5728\u9019\u500b\u4f8b\u5b50\u4e2d\uff0cuser_id\u4f5c\u70baPRIMARY KEY\uff0c\u80fd\u5920\u5feb\u901f\u5b9a\u4f4d\u5230\u7279\u5b9a\u7528\u6236\u7684\u8cc7\u6599\u3002<\/p>\n
2. \u4f7f\u7528LIMIT\u548cALLOW FILTERING<\/h2>\n
\u5728\u67e5\u8a62\u6642\uff0c\u4f7f\u7528LIMIT\u53ef\u4ee5\u9650\u5236\u8fd4\u56de\u7684\u7d50\u679c\u6578\u91cf\uff0c\u9019\u5c0d\u65bc\u63d0\u9ad8\u67e5\u8a62\u6027\u80fd\u975e\u5e38\u6709\u5e6b\u52a9\u3002\u7136\u800c\uff0c\u4f7f\u7528ALLOW FILTERING\u6642\u8981\u8b39\u614e\uff0c\u56e0\u70ba\u9019\u53ef\u80fd\u6703\u5c0e\u81f4\u5168\u8868\u6383\u63cf\uff0c\u5f71\u97ff\u6027\u80fd\u3002<\/p>\n
SELECT * FROM users WHERE name = 'Alice' LIMIT 10 ALLOW FILTERING;\n<\/code><\/pre>\n
\u9019\u689d\u67e5\u8a62\u5c07\u8fd4\u56de\u540d\u5b57\u70baAlice\u7684\u524d10\u500b\u7528\u6236\uff0c\u4f46\u4f7f\u7528ALLOW FILTERING\u53ef\u80fd\u6703\u5f71\u97ff\u6027\u80fd\uff0c\u5efa\u8b70\u5728\u5fc5\u8981\u6642\u4f7f\u7528\u3002<\/p>\n
3. \u4f7f\u7528BATCH\u8a9e\u53e5<\/h2>\n
BATCH\u8a9e\u53e5\u53ef\u4ee5\u7528\u4f86\u5728\u4e00\u6b21\u64cd\u4f5c\u4e2d\u57f7\u884c\u591a\u500b\u63d2\u5165\u6216\u66f4\u65b0\uff0c\u9019\u6a23\u53ef\u4ee5\u6e1b\u5c11\u7db2\u7d61\u5ef6\u9072\uff0c\u63d0\u9ad8\u6548\u7387\u3002\u4e0d\u904e\uff0c\u904e\u5ea6\u4f7f\u7528BATCH\u53ef\u80fd\u6703\u5c0e\u81f4\u6027\u80fd\u4e0b\u964d\uff0c\u56e0\u6b64\u61c9\u8b39\u614e\u4f7f\u7528\u3002<\/p>\n
BATCH\n    INSERT INTO users (user_id, name, email, created_at) VALUES (uuid(), 'Bob', 'bob@example.com', toTimestamp(now()));\n    INSERT INTO users (user_id, name, email, created_at) VALUES (uuid(), 'Charlie', 'charlie@example.com', toTimestamp(now()));\nAPPLY BATCH;\n<\/code><\/pre>\n
\u9019\u6a23\u7684\u64cd\u4f5c\u53ef\u4ee5\u5728\u4e00\u6b21\u8acb\u6c42\u4e2d\u63d2\u5165\u591a\u689d\u8a18\u9304\uff0c\u6e1b\u5c11\u4e86\u591a\u6b21\u8acb\u6c42\u7684\u958b\u92b7\u3002<\/p>\n
4. \u4f7f\u7528\u8cc7\u6599\u6a21\u578b\u512a\u5316\u67e5\u8a62<\/h2>\n
Cassandra\u7684\u8cc7\u6599\u6a21\u578b\u8a2d\u8a08\u61c9\u8a72\u6839\u64da\u67e5\u8a62\u9700\u6c42\u4f86\u9032\u884c\u512a\u5316\u3002\u9019\u610f\u5473\u8457\u5728\u8a2d\u8a08\u8868\u7d50\u69cb\u6642\uff0c\u61c9\u8a72\u8003\u616e\u5230\u5c07\u4f86\u53ef\u80fd\u7684\u67e5\u8a62\u65b9\u5f0f\uff0c\u4e26\u6839\u64da\u9019\u4e9b\u67e5\u8a62\u4f86\u8a2d\u8a08\u8868\u7684\u7d50\u69cb\u3002<\/p>\n
\u4f8b\u5982\uff0c\u5982\u679c\u7d93\u5e38\u9700\u8981\u6839\u64da\u5275\u5efa\u6642\u9593\u67e5\u8a62\u7528\u6236\uff0c\u53ef\u4ee5\u8003\u616e\u5c07created_at\u4f5c\u70baClustering Column\uff1a<\/p>\n
CREATE TABLE users_by_creation (\n    user_id UUID,\n    created_at TIMESTAMP,\n    name TEXT,\n    PRIMARY KEY (created_at, user_id)\n) WITH CLUSTERING ORDER BY (created_at DESC);\n<\/code><\/pre>\n
\u9019\u6a23\u7684\u8a2d\u8a08\u53ef\u4ee5\u4f7f\u5f97\u6839\u64da\u5275\u5efa\u6642\u9593\u7684\u67e5\u8a62\u66f4\u52a0\u9ad8\u6548\u3002<\/p>\n
5. \u4f7f\u7528\u7d22\u5f15<\/h2>\n
Cassandra\u652f\u6301\u4e8c\u7d1a\u7d22\u5f15\uff0c\u53ef\u4ee5\u7528\u4f86\u52a0\u901f\u67d0\u4e9b\u67e5\u8a62\u3002\u96d6\u7136\u4e8c\u7d1a\u7d22\u5f15\u5728\u67d0\u4e9b\u60c5\u6cc1\u4e0b\u975e\u5e38\u6709\u7528\uff0c\u4f46\u5728\u9ad8\u5beb\u5165\u8ca0\u8f09\u7684\u74b0\u5883\u4e2d\uff0c\u4f7f\u7528\u7d22\u5f15\u53ef\u80fd\u6703\u5f71\u97ff\u6027\u80fd\uff0c\u56e0\u6b64\u61c9\u6839\u64da\u5177\u9ad4\u60c5\u6cc1\u4f86\u6c7a\u5b9a\u662f\u5426\u4f7f\u7528\u3002<\/p>\n
CREATE INDEX ON users (email);\n<\/code><\/pre>\n
\u9019\u689d\u8a9e\u53e5\u5c07\u5728email\u5b57\u6bb5\u4e0a\u5275\u5efa\u7d22\u5f15\uff0c\u5f9e\u800c\u52a0\u901f\u57fa\u65bcemail\u7684\u67e5\u8a62\u3002<\/p>\n
\u7e3d\u7d50<\/h2>\n
\u638c\u63e1Cassandra\u7684\u67e5\u8a62\u8a9e\u53e5CQL\u7684\u5c0f\u6280\u5de7\uff0c\u53ef\u4ee5\u5e6b\u52a9\u958b\u767c\u8005\u66f4\u9ad8\u6548\u5730\u9032\u884c\u8cc7\u6599\u7ba1\u7406\u548c\u67e5\u8a62\u3002\u5408\u7406\u8a2d\u8a08PRIMARY KEY\u3001\u4f7f\u7528LIMIT\u548cBATCH\u8a9e\u53e5\u3001\u512a\u5316\u8cc7\u6599\u6a21\u578b\u4ee5\u53ca\u9069\u7576\u4f7f\u7528\u7d22\u5f15\uff0c\u90fd\u662f\u63d0\u5347\u67e5\u8a62\u6027\u80fd\u7684\u91cd\u8981\u65b9\u6cd5\u3002\u5c0d\u65bc\u9700\u8981\u9ad8\u53ef\u7528\u6027\u548c\u53ef\u64f4\u5c55\u6027\u7684\u61c9\u7528\uff0c\u9078\u64c7\u5408\u9069\u7684\u9999\u6e2fVPS<\/a><\/code>\u6216\u96f2\u4f3a\u670d\u5668<\/a><\/code>\u89e3\u6c7a\u65b9\u6848\uff0c\u5c07\u6709\u52a9\u65bc\u66f4\u597d\u5730\u652f\u6301Cassandra\u7684\u904b\u884c\u548c\u7ba1\u7406\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"
\u638c\u63e1Cassandra\u67e5\u8a62\u8a9e\u53e5CQL\u7684\u5c0f\u6280\u5de7\uff0c\u63d0\u5347\u6578\u64da\u67e5\u8a62\u6548\u7387\uff0c\u7c21\u5316\u64cd\u4f5c\u6d41\u7a0b\uff0c\u8b93\u6578\u64da\u7ba1\u7406\u66f4\u8f15\u9b06\u3002<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[101],"tags":[],"class_list":["post-59541","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/59541","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"}],"author":[{"embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/comments?post=59541"}],"version-history":[{"count":1,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/59541\/revisions"}],"predecessor-version":[{"id":59542,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/59541\/revisions\/59542"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=59541"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=59541"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=59541"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}