{"id":168017,"date":"2024-11-06T08:49:17","date_gmt":"2024-11-06T00:49:17","guid":{"rendered":"https:\/\/server.hk\/cnblog\/168017\/"},"modified":"2024-11-06T08:49:18","modified_gmt":"2024-11-06T00:49:18","slug":"%e8%81%8a%e8%81%8a%e6%95%b8%e6%93%9a%e5%ba%ab%e7%9a%84%e4%ba%8b%e5%8b%99%e9%9a%94%e9%9b%a2%e7%b4%9a%e5%88%a5","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/168017\/","title":{"rendered":"\u804a\u804a\u6578\u64da\u5eab\u7684\u4e8b\u52d9\u9694\u96e2\u7d1a\u5225"},"content":{"rendered":"<h1 id=\"%e8%81%8a%e8%81%8a%e6%95%b8%e6%93%9a%e5%ba%ab%e7%9a%84%e4%ba%8b%e5%8b%99%e9%9a%94%e9%9b%a2%e7%b4%9a%e5%88%a5-eqbKVqCiUg\">\u804a\u804a\u6578\u64da\u5eab\u7684\u4e8b\u52d9\u9694\u96e2\u7d1a\u5225<\/h1>\n<p>\u5728\u73fe\u4ee3\u6578\u64da\u5eab\u7ba1\u7406\u7cfb\u7d71\u4e2d\uff0c\u4e8b\u52d9\u7684\u7ba1\u7406\u81f3\u95dc\u91cd\u8981\u3002\u4e8b\u52d9\u9694\u96e2\u7d1a\u5225\u662f\u78ba\u4fdd\u6578\u64da\u4e00\u81f4\u6027\u548c\u5b8c\u6574\u6027\u7684\u95dc\u9375\u56e0\u7d20\u4e4b\u4e00\u3002\u672c\u6587\u5c07\u6df1\u5165\u63a2\u8a0e\u6578\u64da\u5eab\u7684\u4e8b\u52d9\u9694\u96e2\u7d1a\u5225\uff0c\u5305\u62ec\u5176\u5b9a\u7fa9\u3001\u985e\u578b\u53ca\u5176\u5728\u5be6\u969b\u61c9\u7528\u4e2d\u7684\u5f71\u97ff\u3002<\/p>\n<h2 id=\"%e4%bb%80%e9%ba%bc%e6%98%af%e4%ba%8b%e5%8b%99%e9%9a%94%e9%9b%a2%e7%b4%9a%e5%88%a5%ef%bc%9f-eqbKVqCiUg\">\u4ec0\u9ebc\u662f\u4e8b\u52d9\u9694\u96e2\u7d1a\u5225\uff1f<\/h2>\n<p>\u4e8b\u52d9\u9694\u96e2\u7d1a\u5225\u662f\u6307\u5728\u591a\u500b\u4e8b\u52d9\u540c\u6642\u57f7\u884c\u6642\uff0c\u5982\u4f55\u63a7\u5236\u5b83\u5011\u4e4b\u9593\u7684\u76f8\u4e92\u5f71\u97ff\u3002\u6839\u64da\u300aSQL\u6a19\u6e96\u300b\uff0c\u4e8b\u52d9\u9694\u96e2\u7d1a\u5225\u4e3b\u8981\u6709\u56db\u7a2e\uff1a\u8b80\u672a\u63d0\u4ea4\uff08Read Uncommitted\uff09\u3001\u8b80\u5df2\u63d0\u4ea4\uff08Read Committed\uff09\u3001\u53ef\u91cd\u8907\u8b80\uff08Repeatable Read\uff09\u548c\u4e32\u884c\u5316\uff08Serializable\uff09\u3002\u9019\u4e9b\u7d1a\u5225\u7684\u4e3b\u8981\u76ee\u7684\u662f\u5e73\u8861\u6578\u64da\u7684\u4e00\u81f4\u6027\u548c\u7cfb\u7d71\u7684\u6027\u80fd\u3002<\/p>\n<h2 id=\"%e5%9b%9b%e7%a8%ae%e4%ba%8b%e5%8b%99%e9%9a%94%e9%9b%a2%e7%b4%9a%e5%88%a5-eqbKVqCiUg\">\u56db\u7a2e\u4e8b\u52d9\u9694\u96e2\u7d1a\u5225<\/h2>\n<h3 id=\"1-%e8%ae%80%e6%9c%aa%e6%8f%90%e4%ba%a4%ef%bc%88read-uncommitted%ef%bc%89-eqbKVqCiUg\">1. \u8b80\u672a\u63d0\u4ea4\uff08Read Uncommitted\uff09<\/h3>\n<p>\u5728\u9019\u500b\u9694\u96e2\u7d1a\u5225\u4e0b\uff0c\u4e8b\u52d9\u53ef\u4ee5\u8b80\u53d6\u5176\u4ed6\u4e8b\u52d9\u5c1a\u672a\u63d0\u4ea4\u7684\u6578\u64da\u3002\u9019\u610f\u5473\u8457\u53ef\u80fd\u6703\u51fa\u73fe\u300c\u9ad2\u8b80\u300d\uff08Dirty Read\uff09\u7684\u60c5\u6cc1\uff0c\u5373\u4e00\u500b\u4e8b\u52d9\u8b80\u53d6\u5230\u53e6\u4e00\u500b\u4e8b\u52d9\u5c1a\u672a\u63d0\u4ea4\u7684\u6578\u64da\uff0c\u9019\u53ef\u80fd\u5c0e\u81f4\u4e0d\u4e00\u81f4\u7684\u7d50\u679c\u3002<\/p>\n<pre><code>-- \u4e8b\u52d9A\nBEGIN TRANSACTION;\nUPDATE accounts SET balance = balance - 100 WHERE user_id = 1;\n\n-- \u4e8b\u52d9B\nSELECT * FROM accounts WHERE user_id = 1; -- \u53ef\u80fd\u8b80\u53d6\u5230\u672a\u63d0\u4ea4\u7684\u6578\u64da\n<\/code><\/pre>\n<h3 id=\"2-%e8%ae%80%e5%b7%b2%e6%8f%90%e4%ba%a4%ef%bc%88read-committed%ef%bc%89-eqbKVqCiUg\">2. \u8b80\u5df2\u63d0\u4ea4\uff08Read Committed\uff09<\/h3>\n<p>\u5728\u8b80\u5df2\u63d0\u4ea4\u9694\u96e2\u7d1a\u5225\u4e0b\uff0c\u4e8b\u52d9\u53ea\u80fd\u8b80\u53d6\u5df2\u7d93\u63d0\u4ea4\u7684\u6578\u64da\u3002\u9019\u6a23\u53ef\u4ee5\u907f\u514d\u9ad2\u8b80\u7684\u554f\u984c\uff0c\u4f46\u4ecd\u7136\u53ef\u80fd\u51fa\u73fe\u300c\u4e0d\u53ef\u91cd\u8907\u8b80\u300d\uff08Non-repeatable Read\uff09\u7684\u60c5\u6cc1\uff0c\u5373\u5728\u540c\u4e00\u4e8b\u52d9\u4e2d\u591a\u6b21\u8b80\u53d6\u540c\u4e00\u6578\u64da\u6642\uff0c\u53ef\u80fd\u6703\u5f97\u5230\u4e0d\u540c\u7684\u7d50\u679c\u3002<\/p>\n<pre><code>-- \u4e8b\u52d9A\nBEGIN TRANSACTION;\nSELECT * FROM accounts WHERE user_id = 1;\n\n-- \u4e8b\u52d9B\nUPDATE accounts SET balance = balance - 100 WHERE user_id = 1; -- \u4e8b\u52d9B\u63d0\u4ea4\u5f8c\uff0c\u4e8b\u52d9A\u518d\u6b21\u67e5\u8a62\u6642\u53ef\u80fd\u5f97\u5230\u4e0d\u540c\u7d50\u679c\n<\/code><\/pre>\n<h3 id=\"3-%e5%8f%af%e9%87%8d%e8%a4%87%e8%ae%80%ef%bc%88repeatable-read%ef%bc%89-eqbKVqCiUg\">3. \u53ef\u91cd\u8907\u8b80\uff08Repeatable Read\uff09<\/h3>\n<p>\u53ef\u91cd\u8907\u8b80\u9694\u96e2\u7d1a\u5225\u78ba\u4fdd\u5728\u540c\u4e00\u4e8b\u52d9\u4e2d\u591a\u6b21\u8b80\u53d6\u540c\u4e00\u6578\u64da\u6642\uff0c\u7d50\u679c\u662f\u4e00\u81f4\u7684\u3002\u9019\u6a23\u53ef\u4ee5\u907f\u514d\u4e0d\u53ef\u91cd\u8907\u8b80\u7684\u554f\u984c\uff0c\u4f46\u4ecd\u7136\u53ef\u80fd\u51fa\u73fe\u300c\u5e7b\u8b80\u300d\uff08Phantom Read\uff09\u7684\u60c5\u6cc1\uff0c\u5373\u5728\u540c\u4e00\u4e8b\u52d9\u4e2d\uff0c\u7576\u67e5\u8a62\u7684\u7bc4\u570d\u5167\u65b0\u589e\u4e86\u6578\u64da\u6642\uff0c\u6703\u5f71\u97ff\u5230\u67e5\u8a62\u7d50\u679c\u3002<\/p>\n<pre><code>-- \u4e8b\u52d9A\nBEGIN TRANSACTION;\nSELECT * FROM accounts WHERE user_id = 1;\n\n-- \u4e8b\u52d9B\nINSERT INTO accounts (user_id, balance) VALUES (2, 500); -- \u4e8b\u52d9B\u7684\u63d2\u5165\u4e0d\u6703\u5f71\u97ff\u4e8b\u52d9A\u7684\u67e5\u8a62\u7d50\u679c\n<\/code><\/pre>\n<h3 id=\"4-%e4%b8%b2%e8%a1%8c%e5%8c%96%ef%bc%88serializable%ef%bc%89-eqbKVqCiUg\">4. \u4e32\u884c\u5316\uff08Serializable\uff09<\/h3>\n<p>\u4e32\u884c\u5316\u662f\u6700\u9ad8\u7684\u9694\u96e2\u7d1a\u5225\uff0c\u78ba\u4fdd\u4e8b\u52d9\u4e4b\u9593\u5b8c\u5168\u9694\u96e2\u3002\u9019\u610f\u5473\u8457\u5728\u4efb\u4f55\u6642\u5019\uff0c\u53ea\u6709\u4e00\u500b\u4e8b\u52d9\u53ef\u4ee5\u8a2a\u554f\u6578\u64da\uff0c\u5f9e\u800c\u907f\u514d\u4e86\u9ad2\u8b80\u3001\u4e0d\u53ef\u91cd\u8907\u8b80\u548c\u5e7b\u8b80\u7684\u554f\u984c\u3002\u7136\u800c\uff0c\u9019\u7a2e\u9694\u96e2\u7d1a\u5225\u6703\u986f\u8457\u5f71\u97ff\u7cfb\u7d71\u6027\u80fd\uff0c\u56e0\u70ba\u5b83\u6703\u5c0e\u81f4\u4e8b\u52d9\u7684\u7b49\u5f85\u548c\u963b\u585e\u3002<\/p>\n<pre><code>-- \u4e8b\u52d9A\nBEGIN TRANSACTION;\nSELECT * FROM accounts WHERE user_id = 1;\n\n-- \u4e8b\u52d9B\nBEGIN TRANSACTION;\nSELECT * FROM accounts WHERE user_id = 2; -- \u4e8b\u52d9B\u5fc5\u9808\u7b49\u5f85\u4e8b\u52d9A\u5b8c\u6210\n<\/code><\/pre>\n<h2 id=\"%e4%ba%8b%e5%8b%99%e9%9a%94%e9%9b%a2%e7%b4%9a%e5%88%a5%e7%9a%84%e9%81%b8%e6%93%87-eqbKVqCiUg\">\u4e8b\u52d9\u9694\u96e2\u7d1a\u5225\u7684\u9078\u64c7<\/h2>\n<p>\u9078\u64c7\u5408\u9069\u7684\u4e8b\u52d9\u9694\u96e2\u7d1a\u5225\u53d6\u6c7a\u65bc\u61c9\u7528\u7684\u9700\u6c42\u548c\u6027\u80fd\u8003\u91cf\u3002\u5728\u9ad8\u4e26\u767c\u7684\u74b0\u5883\u4e2d\uff0c\u53ef\u80fd\u9700\u8981\u9078\u64c7\u8f03\u4f4e\u7684\u9694\u96e2\u7d1a\u5225\u4ee5\u63d0\u9ad8\u6027\u80fd\uff0c\u800c\u5728\u5c0d\u6578\u64da\u4e00\u81f4\u6027\u8981\u6c42\u8f03\u9ad8\u7684\u60c5\u6cc1\u4e0b\uff0c\u5247\u61c9\u9078\u64c7\u8f03\u9ad8\u7684\u9694\u96e2\u7d1a\u5225\u3002\u958b\u767c\u8005\u9700\u8981\u6839\u64da\u5177\u9ad4\u60c5\u6cc1\u9032\u884c\u6b0a\u8861\u3002<\/p>\n<h2 id=\"%e7%b8%bd%e7%b5%90-eqbKVqCiUg\">\u7e3d\u7d50<\/h2>\n<p>\u4e8b\u52d9\u9694\u96e2\u7d1a\u5225\u5728\u6578\u64da\u5eab\u7ba1\u7406\u4e2d\u626e\u6f14\u8457\u91cd\u8981\u89d2\u8272\uff0c\u5f71\u97ff\u8457\u6578\u64da\u7684\u4e00\u81f4\u6027\u548c\u7cfb\u7d71\u7684\u6027\u80fd\u3002\u4e86\u89e3\u4e0d\u540c\u9694\u96e2\u7d1a\u5225\u7684\u7279\u6027\u53ca\u5176\u9069\u7528\u5834\u666f\uff0c\u5c0d\u65bc\u8a2d\u8a08\u9ad8\u6548\u4e14\u53ef\u9760\u7684\u6578\u64da\u5eab\u7cfb\u7d71\u81f3\u95dc\u91cd\u8981\u3002\u5982\u679c\u60a8\u6b63\u5728\u5c0b\u627e\u9ad8\u6027\u80fd\u7684 <a href=\"https:\/\/server.hk\">\u9999\u6e2fVPS<\/a> \u89e3\u6c7a\u65b9\u6848\uff0cServer.HK \u63d0\u4f9b\u591a\u7a2e\u9078\u64c7\u4ee5\u6eff\u8db3\u60a8\u7684\u9700\u6c42\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u4e86\u89e3\u6578\u64da\u5eab\u7684\u4e8b\u52d9\u9694\u96e2\u7d1a\u5225\uff0c\u63a2\u7d22\u4e0d\u540c\u7d1a\u5225\u5982\u4f55\u5f71\u97ff\u6578\u64da\u4e00\u81f4\u6027\u548c\u4e26\u767c\u6027\uff0c\u63d0\u5347\u7cfb\u7d71\u6027\u80fd\u8207\u53ef\u9760\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-168017","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/168017","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=168017"}],"version-history":[{"count":1,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/168017\/revisions"}],"predecessor-version":[{"id":168018,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/168017\/revisions\/168018"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=168017"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=168017"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=168017"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}