{"id":2005,"date":"2023-04-01T11:38:32","date_gmt":"2023-04-01T03:38:32","guid":{"rendered":"https:\/\/www.appblog.cn\/?p=2005"},"modified":"2023-04-07T10:39:25","modified_gmt":"2023-04-07T02:39:25","slug":"quickly-understand-the-isolation-level-of-database-transactions","status":"publish","type":"post","link":"https:\/\/www.appblog.cn\/index.php\/2023\/04\/01\/quickly-understand-the-isolation-level-of-database-transactions\/","title":{"rendered":"\u3010\u9762\u8bd5\u5fc5\u5907\u3011\u5feb\u901f\u7406\u89e3\u6570\u636e\u5e93\u4e8b\u52a1\u9694\u79bb\u7ea7\u522b"},"content":{"rendered":"<h2>\u4e8b\u52a1\u7b80\u4ecb<\/h2>\n<p>\u76f8\u4fe1\u7528\u8fc7MySQL\u7684\u670b\u53cb\u90fd\u77e5\u9053\u4e8b\u52a1\uff0c\u6211\u4eec\u4e5f\u5e38\u5e38\u901a\u8fc7\u8fd9\u4e2a\u4f8b\u5b50\u6765\u8bb2\u89e3\u4e8b\u52a1\u7684\u4f5c\u7528\uff1aA\u5411B\u8f6c\u8d26\uff0c\u8fd9\u91cc\u53ef\u4ee5\u5206\u4e3a\u4e24\u6b65\u64cd\u4f5c\u6570\u636e\u5e93\uff0cA\u8d26\u6237\u4f59\u989d\u51cf\u5c11\uff0cB\u8d26\u6237\u4f59\u989d\u589e\u52a0\u3002\u4f46\u662f\uff0c\u5982\u679c\u5728A\u8d26\u6237\u4f59\u989d\u51cf\u5c11\u7684\u65f6\u5019\u7a81\u7136\u51fa\u73b0\u4e86\u6570\u636e\u5e93\u5b95\u673a\u4e86\u7b49\u60c5\u51b5\uff0c\u662f\u4e0d\u662f\u4f1a\u51fa\u73b0A\u7684\u4f59\u989d\u53d8\u5c11\u4e86\uff0c\u4f46\u662fB\u7684\u4f59\u989d\u5374\u6ca1\u6709\u589e\u52a0\u7684\u60c5\u51b5\u5462\uff1f\u7b54\u6848\u662f\u5426\u5b9a\u7684\u3002\u539f\u56e0\u5c31\u662f\u6570\u636e\u5e93\u652f\u6301\u4e8b\u52a1\uff08\u5e38\u7528\u7684\u5173\u7cfb\u578b\u6570\u636e\uff0c\u5982MySQL\u3001Oracle\u7b49\uff09\u3002<\/p>\n<p><!-- more --><\/p>\n<p>\u4e8b\u52a1\u662f\u5e94\u7528\u7a0b\u5e8f\u4e2d\u4e00\u7cfb\u5217\u4e25\u5bc6\u7684\u64cd\u4f5c\uff0c\u6240\u6709\u64cd\u4f5c\u5fc5\u987b\u6210\u529f\u5b8c\u6210\uff0c\u5426\u5219\u5728\u6bcf\u4e2a\u64cd\u4f5c\u4e2d\u6240\u4f5c\u7684\u6240\u6709\u66f4\u6539\u90fd\u4f1a\u88ab\u64a4\u6d88\u3002\u4e5f\u5c31\u662f\u4e8b\u52a1\u5177\u6709\u539f\u5b50\u6027\uff0c\u4e00\u4e2a\u4e8b\u52a1\u4e2d\u7684\u4e00\u7cfb\u5217\u7684\u64cd\u4f5c\u8981\u4e48\u5168\u90e8\u6210\u529f\uff0c\u8981\u4e48\u4e00\u4e2a\u90fd\u4e0d\u505a\u3002<\/p>\n<p>\u4e8b\u52a1\u7684\u7ed3\u675f\u6709\u4e24\u79cd\uff0c\u5f53\u4e8b\u52a1\u4e2d\u7684\u6240\u4ee5\u6b65\u9aa4\u5168\u90e8\u6210\u529f\u6267\u884c\u65f6\uff0c\u4e8b\u52a1\u63d0\u4ea4\u3002\u5982\u679c\u5176\u4e2d\u4e00\u4e2a\u6b65\u9aa4\u5931\u8d25\uff0c\u5c06\u53d1\u751f\u56de\u6eda\u64cd\u4f5c\uff0c\u64a4\u6d88\u64a4\u6d88\u4e4b\u524d\u5230\u4e8b\u52a1\u5f00\u59cb\u65f6\u7684\u6240\u6709\u64cd\u4f5c\u3002<\/p>\n<h2>\u4e8b\u52a1\u7684ACID\u7279\u6027<\/h2>\n<p>\u8fd9\u4e2a\u662f\u4e00\u4e2a\u8001\u751f\u5e38\u8c08\u7684\u95ee\u9898\uff0c\u9762\u8bd5\u4e2d\u4e5f\u7ecf\u5e38\u4f1a\u95ee\uff1a\u4e8b\u52a1\u7684ACID\u7279\u6027\u5206\u522b\u662f\u4ec0\u4e48\uff1f\u8fd9\u91cc\u7684ACID\u5206\u522b\u4ee3\u8868\u56db\u4e2a\u5355\u8bcd\uff1a\u539f\u5b50\u6027\uff08Atomicity\uff09\u3001\u4e00\u81f4\u6027\uff08Consistency\uff09\u3001\u9694\u79bb\u6027\uff08Isolation\uff09\u548c\u6301\u7eed\u6027\uff08Durability\uff09\u3002<\/p>\n<p>\uff081\uff09\u539f\u5b50\u6027\u3002\u4e8b\u52a1\u662f\u6570\u636e\u5e93\u7684\u903b\u8f91\u5de5\u4f5c\u5355\u4f4d\uff0c\u4e8b\u52a1\u4e2d\u5305\u542b\u7684\u5404\u64cd\u4f5c\u8981\u4e48\u90fd\u505a\uff0c\u8981\u4e48\u90fd\u4e0d\u505a<\/p>\n<p>\uff082\uff09\u4e00\u81f4\u6027\u3002\u4e8b\u52a1\u6267\u884c\u7684\u7ed3\u679c\u5fc5\u987b\u662f\u4f7f\u6570\u636e\u5e93\u4ece\u4e00\u4e2a\u4e00\u81f4\u6027\u72b6\u6001\u53d8\u5230\u53e6\u4e00\u4e2a\u4e00\u81f4\u6027\u72b6\u6001\u3002\u56e0\u6b64\u5f53\u6570\u636e\u5e93\u53ea\u5305\u542b\u6210\u529f\u4e8b\u52a1\u63d0\u4ea4\u7684\u7ed3\u679c\u65f6\uff0c\u5c31\u8bf4\u6570\u636e\u5e93\u5904\u4e8e\u4e00\u81f4\u6027\u72b6\u6001\u3002\u5982\u679c\u6570\u636e\u5e93\u7cfb\u7edf\u8fd0\u884c\u4e2d\u53d1\u751f\u6545\u969c\uff0c\u6709\u4e9b\u4e8b\u52a1\u5c1a\u672a\u5b8c\u6210\u5c31\u88ab\u8feb\u4e2d\u65ad\uff0c\u8fd9\u4e9b\u672a\u5b8c\u6210\u4e8b\u52a1\u5bf9\u6570\u636e\u5e93\u6240\u505a\u7684\u4fee\u6539\u6709\u4e00\u90e8\u5206\u5df2\u5199\u5165\u7269\u7406\u6570\u636e\u5e93\uff0c\u8fd9\u65f6\u6570\u636e\u5e93\u5c31\u5904\u4e8e\u4e00\u79cd\u4e0d\u6b63\u786e\u7684\u72b6\u6001\uff0c\u6216\u8005\u8bf4\u662f\u4e0d\u4e00\u81f4\u7684\u72b6\u6001\u3002<\/p>\n<p>\uff083\uff09\u9694\u79bb\u6027\u3002\u4e00\u4e2a\u4e8b\u52a1\u7684\u6267\u884c\u4e0d\u80fd\u53d7\u5176\u5b83\u4e8b\u52a1\u5e72\u6270\u3002\u5373\u4e00\u4e2a\u4e8b\u52a1\u5185\u90e8\u7684\u64cd\u4f5c\u53ca\u4f7f\u7528\u7684\u6570\u636e\u5bf9\u5176\u5b83\u5e76\u53d1\u4e8b\u52a1\u662f\u9694\u79bb\u7684\uff0c\u5e76\u53d1\u6267\u884c\u7684\u5404\u4e2a\u4e8b\u52a1\u4e4b\u95f4\u4e0d\u80fd\u4e92\u76f8\u5e72\u6270\u3002<\/p>\n<p>\uff084\uff09\u6301\u7eed\u6027\u3002\u4e5f\u79f0\u6c38\u4e45\u6027\uff0c\u6307\u4e00\u4e2a\u4e8b\u52a1\u4e00\u65e6\u63d0\u4ea4\uff0c\u5b83\u5bf9\u6570\u636e\u5e93\u4e2d\u7684\u6570\u636e\u7684\u6539\u53d8\u5c31\u5e94\u8be5\u662f\u6c38\u4e45\u6027\u7684\u3002\u63a5\u4e0b\u6765\u7684\u5176\u5b83\u64cd\u4f5c\u6216\u6545\u969c\u4e0d\u5e94\u8be5\u5bf9\u5176\u6267\u884c\u7ed3\u679c\u6709\u4efb\u4f55\u5f71\u54cd\u3002<\/p>\n<h2>\u4e8b\u52a1\u7684\u9694\u79bb\u7ea7\u522b<\/h2>\n<p>\u8bf4\u4e8b\u52a1\u9694\u79bb\u7ea7\u522b\u4e4b\u524d\uff0c\u5148\u770b\u770b\u5982\u4e0b\u95ee\u9898\uff1a<\/p>\n<ul>\n<li>\u810f\u8bfb\uff08Dirty Read\uff09<\/li>\n<\/ul>\n<p>\u6240\u8c13\u810f\u8bfb\u662f\u6307\u4e00\u4e2a\u4e8b\u52a1\u4e2d\u8bbf\u95ee\u5230\u4e86\u53e6\u5916\u4e00\u4e2a\u4e8b\u52a1\u672a\u63d0\u4ea4\u7684\u6570\u636e\u3002\u5982A\u4e8b\u52a1\u5bf9\u4e00\u6761\u6570\u636e\u8fdb\u884c\u4e86\u4fee\u6539\uff0c\u4f46\u662f\u4e8b\u52a1\u8fd8\u6ca1\u63d0\u4ea4\uff0c\u6b64\u65f6B\u4e8b\u52a1\u8bfb\u5230\u4e86A\u4e8b\u52a1\u4fee\u6539\u4e86\u4f46\u662f\u672a\u63d0\u4ea4\u7684\u6570\u636e\uff0c\u8fd9\u5c31\u662f\u810f\u8bfb\u3002<\/p>\n<ul>\n<li>\u4e0d\u53ef\u91cd\u590d\u8bfb\uff08Non-repeatable read\uff09<\/li>\n<\/ul>\n<p>\u662f\u6307\u5728\u4e00\u4e2a\u4e8b\u52a1\u5185\uff0c\u591a\u6b21\u8bfb\u540c\u4e00\u6570\u636e\u3002\u5728\u8fd9\u4e2a\u4e8b\u52a1\u8fd8\u6ca1\u6709\u7ed3\u675f\u65f6\uff0c\u53e6\u5916\u4e00\u4e2a\u4e8b\u52a1\u4e5f\u8bbf\u95ee\u8be5\u540c\u4e00\u6570\u636e\u3002\u90a3\u4e48\uff0c\u5728\u7b2c\u4e00\u4e2a\u4e8b\u52a1\u4e2d\u7684\u4e24 \u6b21\u8bfb\u6570\u636e\u4e4b\u95f4\uff0c\u7531\u4e8e\u7b2c\u4e8c\u4e2a\u4e8b\u52a1\u7684\u4fee\u6539\uff0c\u90a3\u4e48\u7b2c\u4e00\u4e2a\u4e8b\u52a1\u4e24\u6b21\u8bfb\u5230\u7684\u7684\u6570\u636e\u53ef\u80fd\u662f\u4e0d\u4e00\u6837\u7684\u3002\u8fd9\u6837\u5c31\u53d1\u751f\u4e86\u5728\u4e00\u4e2a\u4e8b\u52a1\u5185\u4e24\u6b21\u8bfb\u5230\u7684\u6570\u636e\u662f\u4e0d\u4e00\u6837\u7684\uff0c\u56e0\u6b64\u79f0\u4e3a\u662f\u4e0d\u53ef\u91cd\u590d\u8bfb\u3002<\/p>\n<ul>\n<li>\u5e7b\u8bfb(Phantom Read)<\/li>\n<\/ul>\n<p>\u6240\u8c13\u5e7b\u8bfb\u662f\u6307\u540c\u4e00\u4e2a\u4e8b\u52a1\u5185\u591a\u6b21\u67e5\u8be2\u8fd4\u56de\u7684\u7ed3\u679c\u96c6\u4e0d\u4e00\u6837\uff08\u6bd4\u5982\u589e\u52a0\u4e86\u6216\u8005\u51cf\u5c11\u4e86\u884c\u8bb0\u5f55\uff09\u3002\u6bd4\u5982\u540c\u4e00\u4e2a\u4e8b\u52a1A\u5185\u7b2c\u4e00\u6b21\u67e5\u8be2\u65f6\u5019\u6709n\u6761\u8bb0\u5f55\uff0c\u4f46\u662f\u7b2c\u4e8c\u6b21\u540c\u7b49\u6761\u4ef6\u4e0b\u67e5\u8be2\u5374\u53c8n+1\u6761\u8bb0\u5f55\uff0c\u8fd9\u5c31\u597d\u50cf\u4ea7\u751f\u4e86\u5e7b\u89c9\uff0c\u4e3a\u5565\u4e24\u6b21\u7ed3\u679c\u4e0d\u4e00\u6837\u90a3\u3002\u5176\u5b9e\u548c\u4e0d\u53ef\u91cd\u590d\u8bfb\u4e00\u6837\uff0c\u53d1\u751f\u5e7b\u8bfb\u7684\u539f\u56e0\u4e5f\u662f\u53e6\u5916\u4e00\u4e2a\u4e8b\u52a1\u65b0\u589e\u6216\u8005\u5220\u9664\u6216\u8005\u4fee\u6539\u4e86\u7b2c\u4e00\u4e2a\u4e8b\u52a1\u7ed3\u679c\u96c6\u91cc\u9762\u7684\u6570\u636e\u3002\u4e0d\u540c\u5728\u4e8e\u4e0d\u53ef\u91cd\u590d\u8bfb\u662f\u540c\u4e00\u4e2a\u8bb0\u5f55\u7684\u6570\u636e\u5185\u5bb9\u88ab\u4fee\u6539\u4e86\uff0c\u5e7b\u8bfb\u662f\u6570\u636e\u884c\u8bb0\u5f55\u53d8\u591a\u4e86\u6216\u8005\u5c11\u4e86<\/p>\n<p>\u4e86\u89e3\u4e86\u5982\u4e0a\u51e0\u4e2a\u95ee\u9898\u4e4b\u540e\uff0c\u6211\u4eec\u518d\u6765\u770b\u770b\u56db\u79cd\u4e8b\u52a1\u9694\u79bb\u7ea7\u522b\u3002<\/p>\n<p>\uff081\uff09Read Uncommitted\uff08\u8bfb\u53d6\u672a\u63d0\u4ea4\u5185\u5bb9\uff09<\/p>\n<p>\u5728\u8be5\u9694\u79bb\u7ea7\u522b\uff0c\u6240\u6709\u4e8b\u52a1\u90fd\u53ef\u4ee5\u770b\u5230\u5176\u4ed6\u672a\u63d0\u4ea4\u4e8b\u52a1\u7684\u6267\u884c\u7ed3\u679c\u3002\u672c\u9694\u79bb\u7ea7\u522b\u5f88\u5c11\u7528\u4e8e\u5b9e\u9645\u5e94\u7528\uff0c\u56e0\u4e3a\u5b83\u7684\u6027\u80fd\u4e5f\u4e0d\u6bd4\u5176\u4ed6\u7ea7\u522b\u597d\u591a\u5c11\u3002\u8bfb\u53d6\u672a\u63d0\u4ea4\u7684\u6570\u636e\uff0c\u4e5f\u88ab\u79f0\u4e4b\u4e3a\u810f\u8bfb\u3002<\/p>\n<p>\uff082\uff09Read Committed\uff08\u8bfb\u53d6\u63d0\u4ea4\u5185\u5bb9\uff09<\/p>\n<p>\u8fd9\u662f\u5927\u591a\u6570\u6570\u636e\u5e93\u7cfb\u7edf\u7684\u9ed8\u8ba4\u9694\u79bb\u7ea7\u522b\uff08\u4f46\u4e0d\u662fMySQL\u9ed8\u8ba4\u7684\uff09\u3002\u5b83\u6ee1\u8db3\u4e86\u9694\u79bb\u7684\u7b80\u5355\u5b9a\u4e49\uff1a\u4e00\u4e2a\u4e8b\u52a1\u53ea\u80fd\u770b\u89c1\u5df2\u7ecf\u63d0\u4ea4\u4e8b\u52a1\u6240\u505a\u7684\u6539\u53d8\u3002\u8fd9\u5c31\u662f\u6240\u8c13\u7684\u4e0d\u53ef\u91cd\u590d\u8bfb\uff08Non-repeatable read\uff09\u3002<\/p>\n<p>\uff083\uff09Repeatable Read\uff08\u53ef\u91cd\u8bfb\uff09<\/p>\n<p>\u8fd9\u662fMySQL\u7684\u9ed8\u8ba4\u4e8b\u52a1\u9694\u79bb\u7ea7\u522b\uff0c\u5b83\u786e\u4fdd\u540c\u4e00\u4e8b\u52a1\u7684\u591a\u4e2a\u5b9e\u4f8b\u5728\u5e76\u53d1\u8bfb\u53d6\u6570\u636e\u65f6\uff0c\u4f1a\u770b\u5230\u540c\u6837\u7684\u6570\u636e\u884c\u3002\u4e0d\u8fc7\u7406\u8bba\u4e0a\uff0c\u8fd9\u4f1a\u5bfc\u81f4\u53e6\u4e00\u4e2a\u68d8\u624b\u7684\u95ee\u9898\uff1a\u5e7b\u8bfb \uff08Phantom Read\uff09\u3002\u7b80\u5355\u7684\u8bf4\uff0c\u5e7b\u8bfb\u6307\u5f53\u7528\u6237\u8bfb\u53d6\u67d0\u4e00\u8303\u56f4\u7684\u6570\u636e\u884c\u65f6\uff0c\u53e6\u4e00\u4e2a\u4e8b\u52a1\u53c8\u5728\u8be5\u8303\u56f4\u5185\u63d2\u5165\u4e86\u65b0\u884c\uff0c\u5f53\u7528\u6237\u518d\u8bfb\u53d6\u8be5\u8303\u56f4\u7684\u6570\u636e\u884c\u65f6\uff0c\u4f1a\u53d1\u73b0\u6709\u65b0\u7684\u201c\u5e7b\u5f71\u201d\u884c\u3002InnoDB\u548cFalcon\u5b58\u50a8\u5f15\u64ce\u901a\u8fc7\u591a\u7248\u672c\u5e76\u53d1\u63a7\u5236\uff08MVCC\uff0cMultiversion Concurrency Control\uff09\u673a\u5236\u89e3\u51b3\u4e86\u8be5\u95ee\u9898\u3002<\/p>\n<p>\uff084\uff09Serializable\uff08\u4e32\u884c\u5316\uff09<\/p>\n<p>\u8fd9\u662f\u6700\u9ad8\u7684\u9694\u79bb\u7ea7\u522b\uff0c\u5b83\u901a\u8fc7\u5f3a\u5236\u4e8b\u52a1\u6392\u5e8f\uff0c\u4f7f\u4e4b\u4e0d\u53ef\u80fd\u76f8\u4e92\u51b2\u7a81\uff0c\u4ece\u800c\u89e3\u51b3\u5e7b\u8bfb\u95ee\u9898\u3002\u7b80\u8a00\u4e4b\uff0c\u5b83\u662f\u5728\u6bcf\u4e2a\u8bfb\u7684\u6570\u636e\u884c\u4e0a\u52a0\u4e0a\u5171\u4eab\u9501\u3002\u5728\u8fd9\u4e2a\u7ea7\u522b\uff0c\u53ef\u80fd\u5bfc\u81f4\u5927\u91cf\u7684\u8d85\u65f6\u73b0\u8c61\u548c\u9501\u7ade\u4e89\u3002<\/p>\n<h2>\u56db\u79cd\u9694\u79bb\u7ea7\u522b\u53ef\u80fd\u51fa\u73b0\u7684\u95ee\u9898\u603b\u7ed3<\/h2>\n<p>\u9664\u4e86\u6027\u80fd\u6700\u5dee\u7684Serializable\uff08\u4e32\u884c\u5316\uff09\u9694\u79bb\u7ea7\u522b\u4e0d\u4f1a\u51fa\u73b0\u810f\u8bfb\u3001\u4e0d\u53ef\u91cd\u590d\u8bfb\u3001\u5e7b\u8bfb\u95ee\u9898\u4e4b\u5916\uff0c\u5176\u4ed6\u7684\u9694\u79bb\u7ea7\u522b\u90fd\u5b58\u5728\u4e00\u4e2a\u6216\u591a\u4e2a\u95ee\u9898\u3002\u4e0d\u8fc7MySQL\u7684InnoDB\u5f15\u64ce\u901a\u8fc7MVCC\u7684\u65b9\u5f0f\u89e3\u51b3\u4e86Repeatable Read\u7684\u5e7b\u8bfb\u95ee\u9898\u3002<\/p>\n<table>\n<thead>\n<tr>\n<th style=\"text-align: left;\">\u9694\u79bb\u7ea7\u522b<\/th>\n<th style=\"text-align: left;\">\u810f\u8bfb<\/th>\n<th style=\"text-align: left;\">\u4e0d\u53ef\u91cd\u590d\u8bfb<\/th>\n<th style=\"text-align: left;\">\u5e7b\u8bfb<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td style=\"text-align: left;\">\u8bfb\u672a\u63d0\u4ea4\uff08Read Uncommitted\uff09<\/td>\n<td style=\"text-align: left;\">\u221a<\/td>\n<td style=\"text-align: left;\">\u221a<\/td>\n<td style=\"text-align: left;\">\u221a<\/td>\n<\/tr>\n<tr>\n<td style=\"text-align: left;\">\u8bfb\u5df2\u63d0\u4ea4\uff08Read Committed\uff09<\/td>\n<td style=\"text-align: left;\">\u00d7<\/td>\n<td style=\"text-align: left;\">\u221a<\/td>\n<td style=\"text-align: left;\">\u221a<\/td>\n<\/tr>\n<tr>\n<td style=\"text-align: left;\">\u53ef\u91cd\u590d\u8bfb\uff08Repeatable Read\uff09<\/td>\n<td style=\"text-align: left;\">\u00d7<\/td>\n<td style=\"text-align: left;\">\u00d7<\/td>\n<td style=\"text-align: left;\">\u221a<\/td>\n<\/tr>\n<tr>\n<td style=\"text-align: left;\">\u53ef\u4e32\u884c\u5316\uff08Serializable\uff09<\/td>\n<td style=\"text-align: left;\">\u00d7<\/td>\n<td style=\"text-align: left;\">\u00d7<\/td>\n<td style=\"text-align: left;\">\u00d7<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<h2>\u67e5\u770b\u9694\u79bb\u7ea7\u522b<\/h2>\n<pre><code class=\"language-sql\"># \u67e5\u770b\u5f53\u524d\u8fde\u63a5\u7684\u9694\u79bb\u7ea7\u522b\nSELECT @@session.tx_isolation;\n# \u67e5\u770b\u5168\u5c40\u7684\u4e8b\u52a1\u9694\u79bb\u7ea7\u522b\nSELECT @@global.tx_isolation;<\/code><\/pre>\n<h2>\u8bbe\u7f6e\u4e8b\u52a1\u9694\u79bb\u7ea7\u522b<\/h2>\n<p>\uff081\uff09\u5168\u5c40\u4fee\u6539\u90a3\u4e2a\u5f00\u5173\u90a3\u4e2a\u5f00\u5173<\/p>\n<p>\u5728MySQL\u7684\u914d\u7f6e\u6587\u4ef6\u4e0a\u4fee\u6539\uff0c\u5982Windows\u7684<code>mysql.ini<\/code>\uff0cLinux\u4e3a<code>my.cnf<\/code>\u3002<\/p>\n<pre><code class=\"language-sql\">#\u53ef\u9009\u53c2\u6570\u6709\uff1aREAD-UNCOMMITTED, READ-COMMITTED, REPEATABLE-READ, SERIALIZABLE\n[mysqld]\ntransaction-isolation = REPEATABLE-READ<\/code><\/pre>\n<p>\uff082\uff09\u901a\u8fc7\u547d\u4ee4\u5bf9\u5f53\u524d\u8fde\u63a5\u8bbe\u7f6e<\/p>\n<pre><code class=\"language-sql\"># \u53ef\u9009\u53c2\u6570\u4e3a\uff1aread uncommitted\u3001read committed\u3001repeatable read\u3001serializable\nset session transaction isolation level xxx<\/code><\/pre>\n","protected":false},"excerpt":{"rendered":"<p>\u4e8b\u52a1\u7b80\u4ecb \u76f8\u4fe1\u7528\u8fc7MySQL\u7684\u670b\u53cb\u90fd\u77e5\u9053\u4e8b\u52a1\uff0c\u6211\u4eec\u4e5f\u5e38\u5e38\u901a\u8fc7\u8fd9\u4e2a\u4f8b\u5b50\u6765\u8bb2\u89e3\u4e8b\u52a1\u7684\u4f5c\u7528\uff1aA\u5411B\u8f6c\u8d26\uff0c\u8fd9\u91cc\u53ef\u4ee5\u5206\u4e3a [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[8],"tags":[87],"class_list":["post-2005","post","type-post","status-publish","format-standard","hentry","category-database","tag-87"],"_links":{"self":[{"href":"https:\/\/www.appblog.cn\/index.php\/wp-json\/wp\/v2\/posts\/2005","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.appblog.cn\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.appblog.cn\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.appblog.cn\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.appblog.cn\/index.php\/wp-json\/wp\/v2\/comments?post=2005"}],"version-history":[{"count":0,"href":"https:\/\/www.appblog.cn\/index.php\/wp-json\/wp\/v2\/posts\/2005\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.appblog.cn\/index.php\/wp-json\/wp\/v2\/media?parent=2005"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.appblog.cn\/index.php\/wp-json\/wp\/v2\/categories?post=2005"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.appblog.cn\/index.php\/wp-json\/wp\/v2\/tags?post=2005"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}