{"id":58443,"date":"2024-10-12T20:41:36","date_gmt":"2024-10-12T12:41:36","guid":{"rendered":"https:\/\/server.hk\/cnblog\/58443\/"},"modified":"2024-10-12T20:41:36","modified_gmt":"2024-10-12T12:41:36","slug":"android%e6%95%b8%e6%93%9a%e5%ba%ab%e6%9f%a5%e8%a9%a2%e8%aa%9e%e5%8f%a5%ef%bc%9a%e5%a6%82%e4%bd%95%e5%84%aa%e5%8c%96%e6%9f%a5%e8%a9%a2%e6%95%88%e7%8e%87%ef%bc%9f-android%e6%95%b8%e6%93%9a%e5%ba%ab","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/58443\/","title":{"rendered":"Android\u6578\u64da\u5eab\u67e5\u8a62\u8a9e\u53e5\uff1a\u5982\u4f55\u512a\u5316\u67e5\u8a62\u6548\u7387\uff1f (android\u6578\u64da\u5eab\u67e5\u8a62\u8a9e\u53e5)"},"content":{"rendered":"

Android\u6578\u64da\u5eab\u67e5\u8a62\u8a9e\u53e5\uff1a\u5982\u4f55\u512a\u5316\u67e5\u8a62\u6548\u7387\uff1f<\/h1>\n

\u5728Android\u958b\u767c\u4e2d\uff0c\u6578\u64da\u5eab\u7684\u4f7f\u7528\u662f\u4e0d\u53ef\u6216\u7f3a\u7684\u4e00\u90e8\u5206\u3002\u7121\u8ad6\u662f\u4f7f\u7528SQLite\u9084\u662f\u5176\u4ed6\u6578\u64da\u5eab\u7cfb\u7d71\uff0c\u67e5\u8a62\u6548\u7387\u7684\u512a\u5316\u5c0d\u65bc\u61c9\u7528\u7684\u6027\u80fd\u81f3\u95dc\u91cd\u8981\u3002\u672c\u6587\u5c07\u63a2\u8a0e\u5982\u4f55\u512a\u5316Android\u6578\u64da\u5eab\u67e5\u8a62\u8a9e\u53e5\uff0c\u4ee5\u63d0\u9ad8\u67e5\u8a62\u6548\u7387\u3002<\/p>\n

\u7406\u89e3\u6578\u64da\u5eab\u67e5\u8a62\u7684\u57fa\u672c\u6982\u5ff5<\/h2>\n

\u6578\u64da\u5eab\u67e5\u8a62\u8a9e\u53e5\u662f\u7528\u4f86\u5f9e\u6578\u64da\u5eab\u4e2d\u6aa2\u7d22\u6578\u64da\u7684\u6307\u4ee4\u3002\u5728Android\u4e2d\uff0c\u6700\u5e38\u7528\u7684\u6578\u64da\u5eab\u662fSQLite\u3002SQLite\u662f\u4e00\u500b\u8f15\u91cf\u7d1a\u7684\u95dc\u806f\u6578\u64da\u5eab\uff0c\u9069\u5408\u7528\u65bc\u79fb\u52d5\u8a2d\u5099\u3002\u67e5\u8a62\u8a9e\u53e5\u901a\u5e38\u4f7f\u7528SQL\u8a9e\u8a00\u7de8\u5beb\uff0c\u57fa\u672c\u7684\u67e5\u8a62\u8a9e\u53e5\u683c\u5f0f\u5982\u4e0b\uff1a<\/p>\n

SELECT column1, column2 FROM table_name WHERE condition;<\/code><\/pre>\n
\u5728\u9019\u88e1\uff0ccolumn1<\/code>\u548ccolumn2<\/code>\u662f\u8981\u6aa2\u7d22\u7684\u5217\uff0ctable_name<\/code>\u662f\u6578\u64da\u8868\u7684\u540d\u7a31\uff0c\u800ccondition<\/code>\u5247\u662f\u904e\u6ffe\u689d\u4ef6\u3002<\/p>\n
\u512a\u5316\u67e5\u8a62\u6548\u7387\u7684\u7b56\u7565<\/h2>\n
1. \u4f7f\u7528\u7d22\u5f15<\/h3>\n
\u7d22\u5f15\u662f\u63d0\u9ad8\u67e5\u8a62\u6548\u7387\u7684\u6709\u6548\u5de5\u5177\u3002\u901a\u904e\u5728\u7d93\u5e38\u67e5\u8a62\u7684\u5217\u4e0a\u5275\u5efa\u7d22\u5f15\uff0c\u53ef\u4ee5\u986f\u8457\u6e1b\u5c11\u67e5\u8a62\u6642\u9593\u3002\u5275\u5efa\u7d22\u5f15\u7684\u8a9e\u6cd5\u5982\u4e0b\uff1a<\/p>\n
CREATE INDEX index_name ON table_name (column_name);<\/code><\/pre>\n
\u4f8b\u5982\uff0c\u5982\u679c\u7d93\u5e38\u6839\u64da\u7528\u6236ID\u67e5\u8a62\u7528\u6236\u4fe1\u606f\uff0c\u53ef\u4ee5\u5728\u7528\u6236ID\u5217\u4e0a\u5275\u5efa\u7d22\u5f15\uff1a<\/p>\n
CREATE INDEX idx_user_id ON users (user_id);<\/code><\/pre>\n
2. \u907f\u514d\u4f7f\u7528SELECT *<\/h3>\n
\u4f7f\u7528SELECT *<\/code>\u6703\u6aa2\u7d22\u8868\u4e2d\u7684\u6240\u6709\u5217\uff0c\u9019\u6a23\u6703\u589e\u52a0\u4e0d\u5fc5\u8981\u7684\u6578\u64da\u50b3\u8f38\u548c\u8655\u7406\u6642\u9593\u3002\u61c9\u8a72\u660e\u78ba\u6307\u5b9a\u9700\u8981\u7684\u5217\uff1a<\/p>\n
SELECT user_id, user_name FROM users WHERE user_id = 1;<\/code><\/pre>\n
3. \u4f7f\u7528LIMIT\u9650\u5236\u7d50\u679c\u96c6<\/h3>\n
\u5728\u67e5\u8a62\u4e2d\u4f7f\u7528LIMIT<\/code>\u53ef\u4ee5\u9650\u5236\u8fd4\u56de\u7684\u7d50\u679c\u6578\u91cf\uff0c\u9019\u5c0d\u65bc\u9700\u8981\u986f\u793a\u90e8\u5206\u6578\u64da\u7684\u60c5\u6cc1\u7279\u5225\u6709\u7528\uff1a<\/p>\n
SELECT * FROM users LIMIT 10;<\/code><\/pre>\n
4. \u4f7f\u7528JOIN\u800c\u975e\u5b50\u67e5\u8a62<\/h3>\n
\u5728\u67d0\u4e9b\u60c5\u6cc1\u4e0b\uff0c\u4f7f\u7528JOIN\u8a9e\u53e5\u6bd4\u4f7f\u7528\u5b50\u67e5\u8a62\u66f4\u9ad8\u6548\u3002JOIN\u53ef\u4ee5\u5728\u55ae\u500b\u67e5\u8a62\u4e2d\u6aa2\u7d22\u591a\u500b\u8868\u7684\u6578\u64da\uff0c\u5f9e\u800c\u6e1b\u5c11\u67e5\u8a62\u7684\u8907\u96dc\u6027\u548c\u57f7\u884c\u6642\u9593\uff1a<\/p>\n
SELECT users.user_name, orders.order_id \nFROM users \nJOIN orders ON users.user_id = orders.user_id;<\/code><\/pre>\n
5. \u9069\u7576\u4f7f\u7528\u4e8b\u52d9<\/h3>\n
\u5728\u9032\u884c\u591a\u500b\u6578\u64da\u5eab\u64cd\u4f5c\u6642\uff0c\u4f7f\u7528\u4e8b\u52d9\u53ef\u4ee5\u63d0\u9ad8\u6548\u7387\u3002\u4e8b\u52d9\u53ef\u4ee5\u78ba\u4fdd\u64cd\u4f5c\u7684\u539f\u5b50\u6027\uff0c\u4e26\u6e1b\u5c11\u6578\u64da\u5eab\u7684\u9396\u5b9a\u6642\u9593\uff1a<\/p>\n
db.beginTransaction();\n\/\/ \u57f7\u884c\u591a\u500b\u64cd\u4f5c\ndb.setTransactionSuccessful();\ndb.endTransaction(); <\/code><\/pre>\n
\u6e2c\u8a66\u548c\u5206\u6790\u67e5\u8a62\u6027\u80fd<\/h2>\n
\u512a\u5316\u67e5\u8a62\u5f8c\uff0c\u61c9\u8a72\u9032\u884c\u6027\u80fd\u6e2c\u8a66\u3002\u53ef\u4ee5\u4f7f\u7528SQLite\u7684EXPLAIN QUERY PLAN\u547d\u4ee4\u4f86\u5206\u6790\u67e5\u8a62\u7684\u57f7\u884c\u8a08\u5283\uff0c\u5f9e\u800c\u627e\u51fa\u6f5b\u5728\u7684\u6027\u80fd\u74f6\u9838\uff1a<\/p>\n
EXPLAIN QUERY PLAN SELECT * FROM users WHERE user_id = 1;<\/code><\/pre>\n
\u9019\u5c07\u986f\u793a\u67e5\u8a62\u7684\u57f7\u884c\u6b65\u9a5f\uff0c\u5e6b\u52a9\u958b\u767c\u8005\u9032\u4e00\u6b65\u512a\u5316\u67e5\u8a62\u3002<\/p>\n
\u7e3d\u7d50<\/h2>\n
\u512a\u5316Android\u6578\u64da\u5eab\u67e5\u8a62\u8a9e\u53e5\u662f\u63d0\u5347\u61c9\u7528\u6027\u80fd\u7684\u91cd\u8981\u6b65\u9a5f\u3002\u901a\u904e\u4f7f\u7528\u7d22\u5f15\u3001\u907f\u514d\u4f7f\u7528SELECT *<\/code>\u3001\u9650\u5236\u7d50\u679c\u96c6\u3001\u4f7f\u7528JOIN\u4ee5\u53ca\u9069\u7576\u4f7f\u7528\u4e8b\u52d9\uff0c\u53ef\u4ee5\u986f\u8457\u63d0\u9ad8\u67e5\u8a62\u6548\u7387\u3002\u6b64\u5916\uff0c\u5b9a\u671f\u6e2c\u8a66\u548c\u5206\u6790\u67e5\u8a62\u6027\u80fd\u4e5f\u662f\u4e0d\u53ef\u5ffd\u8996\u7684\u90e8\u5206\u3002\u5c0d\u65bc\u9700\u8981\u9ad8\u6548\u6578\u64da\u8655\u7406\u7684\u61c9\u7528\uff0c\u9078\u64c7\u5408\u9069\u7684VPS<\/a><\/code>\u6216\u9999\u6e2f\u4f3a\u670d\u5668<\/a><\/code>\u4f86\u652f\u6301\u5f8c\u7aef\u6578\u64da\u5eab\u7684\u904b\u884c\u4e5f\u662f\u4e00\u500b\u660e\u667a\u7684\u9078\u64c7\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"
\u63a2\u7d22\u5982\u4f55\u512a\u5316Android\u6578\u64da\u5eab\u67e5\u8a62\u8a9e\u53e5\uff0c\u63d0\u9ad8\u67e5\u8a62\u6548\u7387\uff0c\u63d0\u5347\u61c9\u7528\u6027\u80fd\uff0c\u78ba\u4fdd\u6578\u64da\u8655\u7406\u66f4\u5feb\u901f\u6d41\u66a2\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-58443","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/58443","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=58443"}],"version-history":[{"count":1,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/58443\/revisions"}],"predecessor-version":[{"id":58444,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/58443\/revisions\/58444"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=58443"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=58443"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=58443"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}