{"id":2081,"date":"2023-04-01T21:50:29","date_gmt":"2023-04-01T13:50:29","guid":{"rendered":"https:\/\/www.appblog.cn\/?p=2081"},"modified":"2023-04-06T15:49:34","modified_gmt":"2023-04-06T07:49:34","slug":"introduction-to-mysql-transactions","status":"publish","type":"post","link":"https:\/\/www.appblog.cn\/index.php\/2023\/04\/01\/introduction-to-mysql-transactions\/","title":{"rendered":"MySQL\u4e8b\u52a1\u521d\u8bc6"},"content":{"rendered":"<h2>MySQL \u4e2d\u7684\u4e8b\u52a1\uff1f<\/h2>\n<p>\u5bf9 MySQL \u6765\u8bf4\uff0c\u4e8b\u52a1\u901a\u5e38\u662f\u4e00\u7ec4\u5305\u542b\u5bf9\u6570\u636e\u5e93\u64cd\u4f5c\u7684\u96c6\u5408\u3002\u5728\u6267\u884c\u65f6\uff0c\u53ea\u6709\u5728\u8be5\u7ec4\u5185\u7684\u4e8b\u52a1\u90fd\u6267\u884c\u6210\u529f\uff0c\u8fd9\u4e2a\u4e8b\u52a1\u624d\u7b97\u6267\u884c\u6210\u529f\uff0c\u5426\u5219\u5c31\u7b97\u5931\u8d25\u3002MySQL \u4e2d\uff0c\u4e8b\u52a1\u652f\u6301\u662f\u5728\u5f15\u64ce\u5c42\u5b9e\u73b0\u7684\uff0c\u50cf MySQL \u539f\u751f\u7684 MyISAM \u5f15\u64ce\u5c31\u4e0d\u652f\u6301\u4e8b\u52a1\uff0c\u8fd9\u4e5f\u662f\u88ab InooDB \u53d6\u4ee3\u7684\u91cd\u8981\u539f\u56e0\u3002<\/p>\n<p><!-- more --><\/p>\n<p>\u4e3a\u4ec0\u4e48\u8981\u6709\u4e8b\u52a1\u5462\uff0c\u4e3e\u4e2a\u4f8b\u5b50\u6765\u8bf4\uff0c\u4f60\u7684\u8d26\u6237\u6709 100 \u5143\uff0c\u73b0\u5728\u60f3\u7ed9\u670b\u53cb\u8f6c\u8d26 100 \u5143\u3002\u5176\u4e2d\u5c31\u4f1a\u5305\u542b\u4e24\u4e2a\u5f88\u91cd\u8981\u7684\u64cd\u4f5c\uff0c\u4f60\u7684\u8d26\u6237\u51cf 100 \u5143\uff0c\u670b\u53cb\u8d26\u6237\u591a 100 \u5143\u3002\u7531\u4e8e\u8f6c\u8d26\u8fc7\u7a0b\u4e2d\u51fa\u73b0\u5931\u8d25\u662f\u5f88\u5e38\u89c1\u7684\uff0c\u5047\u8bbe\u64cd\u4f5c\u4e0d\u5305\u542b\u5728\u4e8b\u52a1\u5185\uff0c\u4f60\u7684\u8d26\u6237\u51cf\u94b1\u64cd\u4f5c\u6210\u529f\uff0c\u670b\u53cb\u8d26\u6237\u52a0\u94b1\u64cd\u4f5c\u5931\u8d25\u3002\u5c31\u4f1a\u51fa\u73b0\uff0c\u4f60\u7684\u8d26\u6237\u6263\u94b1\uff0c\u5bf9\u65b9\u6ca1\u6709\u6536\u5230\u94b1\u7684\u60c5\u51b5\u3002<\/p>\n<p>\u518d\u6bd4\u5982\uff0c\u5728\u53d1\u8d77\u8f6c\u8d26\u64cd\u4f5c\u65f6\uff0c\u7531\u4e8e\u7cfb\u7edf\u9700\u8981\u8fdb\u884c\u50cf\u67e5\u8be2\u4f59\u989d\uff0c\u8ba1\u7b97\uff0c\u66f4\u65b0\u4f59\u989d\u7684\u64cd\u4f5c\uff0c\u5982\u679c\u5728\u7b49\u5f85\u65f6\u95f4\u5185\uff0c\u53c8\u53d1\u8d77\u4e86\u8f6c\u8d26\u64cd\u4f5c\uff0c\u4f46\u76ee\u524d\u66f4\u65b0\u4f59\u989d\u7684\u64cd\u4f5c\u8fd8\u6ca1\u6709\u6210\u529f\uff0c\u5c31\u4f1a\u51fa\u73b0\u4f60\u7684 100 \u5143\uff0c\u53ef\u4ee5\u7ed9\u522b\u4eba\u8f6c\u8d26\u591a\u6b21\u7684\u60c5\u51b5\uff0c\u8fd9\u5bf9\u4e8e\u94f6\u884c\u6765\u8bf4\u662f\u80af\u5b9a\u4e0d\u5141\u8bb8\u7684\u3002<\/p>\n<p>\u5bf9\u4e8e\u4e00\u4e2a\u4e8b\u52a1\u6765\u8bf4\u901a\u5e38\u8981\u6ee1\u8db3\u56db\u4e2a\u7279\u6027\uff0c\u4e5f\u5c31\u662f\u901a\u5e38\u6240\u8bf4\u7684 ACID:<\/p>\n<ul>\n<li>Atomicity &#8211; \u4fdd\u8bc1\u5728\u4e00\u4e2a\u5de5\u4f5c\u5355\u5143\uff08\u5c31\u662f\u4e00\u7ec4\u64cd\u4f5c\uff09\u4e2d\u6240\u6709\u7684\u64cd\u4f5c\u90fd\u6267\u884c\u6210\u529f\uff0c\u5426\u5219\u7684\u8bdd\u5f53\u524d\u8fd9\u4e2a\u4e8b\u52a1\u5c31\u4f1a\u5931\u8d25\uff0c\u4e4b\u524d\u7684\u64cd\u4f5c\u90fd\u88ab\u4f1a\u56de\u6eda<\/li>\n<li>Consistency &#8211; \u4fdd\u8bc1\u4e00\u4e2a\u4e8b\u52a1\u88ab\u6210\u529f\u63d0\u4ea4\u540e\uff0c\u6570\u636e\u5e93\u7684\u72b6\u6001\u662f\u4ece\u4e00\u81f4\u6027\u72b6\u6001\u53d8\u6210\u53e6\u4e00\u4e2a\u4e00\u81f4\u6027\u72b6\u6001<\/li>\n<li>Isolation &#8211; \u4fdd\u8bc1\u6bcf\u4e2a\u4e8b\u52a1\u4e2d\u7684\u64cd\u4f5c\u65f6\u662f\u72ec\u7acb\u7684\uff0c\u5bf9\u4e8e\u5176\u4ed6\u4e8b\u52a1\u6ca1\u6709\u5f71\u54cd<\/li>\n<li>Durability &#8211; \u5bf9\u4e8e\u5df2\u7ecf\u63d0\u4ea4\u7684\u4e8b\u52a1\uff0c\u5373\u4f7f\u5728\u6570\u636e\u5e93\u635f\u574f\u7684\u60c5\u51b5\u4e0b\uff0c\u4e5f\u4e0d\u4f1a\u9020\u6210\u6570\u636e\u7684\u4e22\u5931\u548c\u635f\u574f<\/li>\n<\/ul>\n<h2>MySQL \u4e2d\u7684\u4e8b\u52a1\u9694\u79bb\u662f\u5982\u4f55\u5b9e\u73b0\u7684\uff1f<\/h2>\n<p>\u5f53\u6570\u636e\u5e93\u4e2d\u6709\u591a\u4e2a\u4e8b\u52a1\u540c\u65f6\u6267\u884c\u65f6\uff0c\u5c31\u53ef\u80fd\u4f1a\u51fa\u73b0\u810f\u8bfb\uff0c\u5e7b\u8bfb\uff0c\u4e0d\u53ef\u91cd\u590d\u8bfb\u7684\u95ee\u9898\uff0c\u4e3a\u4e86\u89e3\u51b3\u8fd9\u4e9b\u95ee\u9898\uff0c\u5c31\u51fa\u73b0\u4e86&quot;\u9694\u79bb\u7ea7\u522b&quot;\u7684\u6982\u5ff5\u3002<\/p>\n<h3>\u4e8b\u52a1\u9694\u79bb\u7684\u95ee\u9898<\/h3>\n<p><strong>\u810f\u8bfb<\/strong>\uff1a\u4e8b\u52a1 A \u4e2d\u8bbf\u95ee\u4e86\u4e8b\u52a1 B \u4e2d\u672a\u63d0\u4ea4\u7684\u6570\u636e\u3002\u8fd9\u91cc Transaction 1 \u8bfb\u5230\u4e86 Transaction 2 \u4e2d\u672a\u63d0\u4ea4\u7684\u5e74\u9f84\u6570\u636e\u3002<\/p>\n<p><img decoding=\"async\" src=\"http:\/\/www.yezhou.me\/AppBlog\/images\/\u6570\u636e\u5e93\/\u4e8b\u52a1\u9694\u79bb-\u810f\u8bfb.png\" alt=\"\u4e8b\u52a1\u9694\u79bb-\u810f\u8bfb\" \/><\/p>\n<p><strong>\u4e0d\u53ef\u91cd\u590d\u8bfb<\/strong>\uff1a\u4e8b\u52a1 A \u4e2d\u591a\u6b21\u67e5\u8be2\u540c\u4e00\u6570\u636e\uff0c\u4f46\u7531\u4e8e\u4e8b\u52a1 B \u5728\u4e8b\u52a1 A \u4e24\u6b21\u67e5\u8be2\u4e2d\uff0c\u4fee\u6539\u4e86\u6539\u6570\u636e\u7684\u503c\uff0c\u5bfc\u81f4\u4e24\u6b21\u67e5\u8be2\u7684\u7ed3\u679c\u4e0d\u4e00\u6837\u3002\u4e0b\u9762 Transaction 1 \u4e2d\u7684\u4e24\u6b21\u67e5\u8be2\u67e5\u8be2\u7ed3\u679c\u662f\u4e00\u81f4\u7684\uff0c\u7b2c\u4e8c\u6b21\u8bfb\u5230\u7684 age \u5df2\u7ecf\u88ab\u4fee\u6539\u7684\u5185\u5bb9\u3002<\/p>\n<p><img decoding=\"async\" src=\"http:\/\/www.yezhou.me\/AppBlog\/images\/\u6570\u636e\u5e93\/\u4e8b\u52a1\u9694\u79bb-\u4e0d\u53ef\u91cd\u590d\u8bfb.png\" alt=\"\u4e8b\u52a1\u9694\u79bb-\u4e0d\u53ef\u91cd\u590d\u8bfb\" \/><\/p>\n<p><strong>\u5e7b\u8bfb<\/strong>\uff1a\u901a\u5e38\u53d1\u751f\u5728\u4e8b\u52a1 B \u5bf9\u4e8b\u52a1 A \u6b63\u5728\u8bfb\u53d6\u7684\u5185\u5bb9\uff0c\u6dfb\u52a0\u6216\u5220\u9664\u4e86\u4e00\u6761\u6570\u636e\u3002\u9020\u6210\u6570\u636e\u83ab\u540d\u51fa\u73b0\u6216\u8005\u6d88\u5931\u7684\u60c5\u51b5\u3002\u8fd9\u91cc Transaction 1 \u4e2d\uff0c\u4e24\u6b21\u67e5\u8be2\u7684\u7ed3\u679c\u5e76\u4e0d\u4e00\u81f4\uff0c\u7b2c\u4e8c\u6b21\u67e5\u8be2\u4f1a\u591a\u51fa\u4e00\u6761\u8bb0\u5f55\u3002<\/p>\n<p><img decoding=\"async\" src=\"http:\/\/www.yezhou.me\/AppBlog\/images\/\u6570\u636e\u5e93\/\u4e8b\u52a1\u9694\u79bb-\u5e7b\u8bfb.png\" alt=\"\u4e8b\u52a1\u9694\u79bb-\u5e7b\u8bfb\" \/><\/p>\n<ul>\n<li>\u810f\u8bfb\uff1a\u6570\u636e\u8bfb\u9519\u65b9\u53ea\u8bfb\u4e86\u4e00\u6b21\u6570\u636e\u5e93\uff0c\u8bfb\u5230\u7684\u6570\u636e\u662f\u9519\u8bef\u7684<\/li>\n<li>\u4e0d\u53ef\u91cd\u590d\u8bfb\uff1a\u6570\u636e\u8bfb\u9519\u65b9\u8bfb\u4e86\u4e24\u6b21\u6570\u636e\u5e93\uff0c\u4e24\u4e2a\u8bfb\u53d6\u7684\u6570\u636e\u5185\u5bb9\u4e0d\u4e00\u81f4<\/li>\n<li>\u5e7b\u8bfb\uff1a\u6570\u636e\u8bfb\u9519\u65b9\u8bfb\u4e86\u4e24\u6b21\u6570\u636e\u5e93\uff0c\u4e24\u4e2a\u8bfb\u53d6\u7684\u6570\u636e\u6761\u6570\u4e0d\u4e00\u81f4<\/li>\n<\/ul>\n<h3>\u4e8b\u52a1\u7684\u9694\u79bb\u7ea7\u522b<\/h3>\n<table>\n<thead>\n<tr>\n<th style=\"text-align: left;\">\u9694\u79bb\u7ea7\u522b<\/th>\n<th style=\"text-align: left;\">\u89e3\u91ca<\/th>\n<th style=\"text-align: left;\">\u53ef\u80fd\u51fa\u73b0\u7684\u95ee\u9898<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td style=\"text-align: left;\">\u8bfb\u672a\u63d0\u4ea4(RU)<\/td>\n<td style=\"text-align: left;\">\u8bfb\u672a\u63d0\u4ea4\u662f\u6307\uff0c\u4e00\u4e2a\u4e8b\u52a1\u8fd8\u6ca1\u63d0\u4ea4\u65f6\uff0c\u5b83\u505a\u7684\u53d8\u66f4\u5c31\u80fd\u88ab\u522b\u7684\u4e8b\u52a1\u770b\u5230<\/td>\n<td style=\"text-align: left;\">\u810f\u8bfb\uff0c\u4e0d\u53ef\u91cd\u590d\u8bfb\uff0c\u5e7b\u8bfb<\/td>\n<\/tr>\n<tr>\n<td style=\"text-align: left;\">\u8bfb\u63d0\u4ea4(RC)<\/td>\n<td style=\"text-align: left;\">\u8bfb\u63d0\u4ea4\u662f\u6307\uff0c\u4e00\u4e2a\u4e8b\u52a1\u63d0\u4ea4\u4e4b\u540e\uff0c\u5b83\u505a\u7684\u53d8\u66f4\u624d\u4f1a\u88ab\u5176\u4ed6\u4e8b\u52a1\u770b\u5230<\/td>\n<td style=\"text-align: left;\">\u4e0d\u53ef\u91cd\u590d\u8bfb\uff0c\u5e7b\u8bfb<\/td>\n<\/tr>\n<tr>\n<td style=\"text-align: left;\">\u53ef\u91cd\u590d\u8bfb(RR)<\/td>\n<td style=\"text-align: left;\">\u53ef\u91cd\u590d\u8bfb\u662f\u6307\uff0c\u4e00\u4e2a\u4e8b\u52a1\u6267\u884c\u8fc7\u7a0b\u4e2d\u770b\u5230\u7684\u6570\u636e\uff0c\u603b\u662f\u8ddf\u8fd9\u4e2a\u4e8b\u52a1\u5728\u542f\u52a8\u65f6\u770b\u5230\u7684\u6570\u636e\u662f\u4e00\u81f4\u7684<br \/>\u5f53\u7136\u5728\u53ef\u91cd\u590d\u8bfb\u9694\u79bb\u7ea7\u522b\u4e0b\uff0c\u672a\u63d0\u4ea4\u53d8\u66f4\u5bf9\u5176\u4ed6\u4e8b\u52a1\u4e5f\u662f\u4e0d\u53ef\u89c1\u7684<\/td>\n<td style=\"text-align: left;\">\u5e7b\u8bfb<\/td>\n<\/tr>\n<tr>\n<td style=\"text-align: left;\">\u4e32\u884c\u5316(S+)<\/td>\n<td style=\"text-align: left;\">\u4e32\u884c\u5316\uff0c\u987e\u540d\u601d\u4e49\u662f\u5bf9\u4e8e\u540c\u4e00\u884c\u8bb0\u5f55\uff0c\u201c\u5199\u201d\u4f1a\u52a0\u201c\u5199\u9501\u201d\uff0c\u201c\u8bfb\u201d\u4f1a\u52a0\u201c\u8bfb\u9501\u201d<br \/>\u5f53\u51fa\u73b0\u8bfb\u5199\u9501\u51b2\u7a81\u7684\u65f6\u5019\uff0c\u540e\u8bbf\u95ee\u7684\u4e8b\u52a1\u5fc5\u987b\u7b49\u524d\u4e00\u4e2a\u4e8b\u52a1\u6267\u884c\u5b8c\u6210\uff0c\u624d\u80fd\u7ee7\u7eed\u6267\u884c<\/td>\n<td style=\"text-align: left;\">\u65e0<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<blockquote>\n<p>\u5728 MySQL \u4e2d RR \u7ea7\u522b\u5f15\u5165\u4e86\u95f4\u9699\u9501\uff0c\u89e3\u51b3\u4e86\u5e7b\u8bfb\u7684\u95ee\u9898\u3002<\/p>\n<\/blockquote>\n<p>\u4e3e\u4e00\u4e2a\u5b9e\u9645\u7684\u4f8b\u5b50\uff0c\u6765\u770b\u4e00\u4e0b\u8fd9\u56db\u79cd\u9694\u79bb\u7ea7\u522b\u5bf9\u5e94\u7684\u7ed3\u679c\uff0c\u5047\u8bbe\u8868\u7ed3\u6784\u5982\u4e0b\uff1a<\/p>\n<pre><code class=\"language-sql\">mysql&gt; create table T(c int) engine=InnoDB;\ninsert into T(c) values(1);<\/code><\/pre>\n<p>\u6b64\u65f6\u53d1\u751f\u7684\u4e8b\u52a1\u5982\u4e0b\uff1a<\/p>\n<table>\n<thead>\n<tr>\n<th style=\"text-align: left;\">\u4e8b\u52a1 A<\/th>\n<th style=\"text-align: left;\">\u4e8b\u52a1 B<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td style=\"text-align: left;\">begin;<\/td>\n<td style=\"text-align: left;\"><\/td>\n<\/tr>\n<tr>\n<td style=\"text-align: left;\">SELECT c FROM T; # c \u7b49\u4e8e 1<\/td>\n<td style=\"text-align: left;\">begin;<\/td>\n<\/tr>\n<tr>\n<td style=\"text-align: left;\"><\/td>\n<td style=\"text-align: left;\">UPDATE t SET c=c+1 where c=1; # c \u7b49\u4e8e2<\/td>\n<\/tr>\n<tr>\n<td style=\"text-align: left;\">SELECT c FROM T; # \u67e5\u51fa\u6765\u7684\u503c\u4e3a V1<\/td>\n<td style=\"text-align: left;\"><\/td>\n<\/tr>\n<tr>\n<td style=\"text-align: left;\"><\/td>\n<td style=\"text-align: left;\">commit;<\/td>\n<\/tr>\n<tr>\n<td style=\"text-align: left;\">SELECT c FROM T; # \u67e5\u51fa\u6765\u7684\u503c\u4e3a V2<\/td>\n<td style=\"text-align: left;\"><\/td>\n<\/tr>\n<tr>\n<td style=\"text-align: left;\">commit;<\/td>\n<td style=\"text-align: left;\"><\/td>\n<\/tr>\n<tr>\n<td style=\"text-align: left;\">SELECT c FROM T; # \u67e5\u51fa\u6765\u7684\u503c\u4e3a V3<\/td>\n<td style=\"text-align: left;\"><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<table>\n<thead>\n<tr>\n<th style=\"text-align: left;\">\u9694\u79bb\u7ea7\u522b<\/th>\n<th style=\"text-align: left;\">\u8fd4\u56de\u7ed3\u679c<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td style=\"text-align: left;\">\u8bfb\u672a\u63d0\u4ea4<\/td>\n<td style=\"text-align: left;\">V1 \u662f 2\u3002\u4e8b\u52a1 B \u867d\u7136\u8fd8\u6ca1\u6709\u63d0\u4ea4\uff0c\u4f46\u662f\u7ed3\u679c\u5df2\u7ecf\u88ab A \u770b\u5230\u4e86\u3002<br \/>\u56e0\u6b64\uff0cV2\u3001V3 \u4e5f\u90fd\u662f 2<\/td>\n<\/tr>\n<tr>\n<td style=\"text-align: left;\">\u8bfb\u63d0\u4ea4<\/td>\n<td style=\"text-align: left;\">V1 \u662f 1\uff0cV2 \u7684\u503c\u662f 2\u3002\u4e8b\u52a1 B \u7684\u66f4\u65b0\u5728\u63d0\u4ea4\u540e\u624d\u80fd\u88ab A \u770b\u5230\u3002<br \/>\u6240\u4ee5\uff0cV3 \u7684\u503c\u4e5f\u662f 2<\/td>\n<\/tr>\n<tr>\n<td style=\"text-align: left;\">\u53ef\u91cd\u590d\u8bfb<\/td>\n<td style=\"text-align: left;\">\u5219 V1\u3001V2 \u662f 1\uff0cV3 \u662f 2\u3002<br \/>V2 \u8fd8\u662f 1 \u7684\u539f\u56e0\uff0c\u9700\u8981\u9075\u5faa\uff1a\u4e8b\u52a1\u5728\u6267\u884c\u671f\u95f4\u770b\u5230\u7684\u6570\u636e\u524d\u540e\u5fc5\u987b\u662f\u4e00\u81f4\u7684<\/td>\n<\/tr>\n<tr>\n<td style=\"text-align: left;\">\u4e32\u884c\u5316<\/td>\n<td style=\"text-align: left;\">\u4e8b\u52a1 B \u6267\u884c\u201c\u5c06 1 \u6539\u6210 2\u201d\u65f6\uff0c\u4f1a\u88ab\u9501\u4f4f\u3002\u76f4\u5230\u4e8b\u52a1 A \u63d0\u4ea4\u540e\uff0c\u4e8b\u52a1 B \u624d\u53ef\u4ee5\u7ee7\u7eed\u6267\u884c\u3002<br \/>\u6240\u4ee5\u4ece A \u7684\u89d2\u5ea6\u770b\uff0c V1\u3001V2 \u503c\u662f 1\uff0cV3 \u7684\u503c\u662f 2<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>\u6267\u884c\u7684\u6548\u7387\u4f1a\u548c\u6267\u884c\u7684\u7ea7\u522b\u6709\u5173\uff0c\u9694\u79bb\u7684\u8d8a\u9ad8\uff0c\u6548\u7387\u8d8a\u4f4e\uff0c\u9700\u8981\u5728\u4e8c\u8005\u95f4\u5bfb\u627e\u5e73\u8861\u3002<\/p>\n<h3>\u4e8b\u52a1\u9694\u79bb\u7684\u5e94\u7528\u573a\u666f\uff1f<\/h3>\n<p>\uff081\uff09\u8bfb\u672a\u63d0\u4ea4\uff1a<\/p>\n<p>\u8fd9\u4e2a\u57fa\u672c\u6ca1\u4eba\u4f1a\u9009\u62e9\uff0c\u8fde\u4e8b\u52a1\u90fd\u6784\u4e0d\u6210\u3002<\/p>\n<p>\uff082\uff09\u8bfb\u63d0\u4ea4\uff1a<\/p>\n<p>\u4e00\u822c\u4e92\u8054\u7f51\u516c\u53f8\u7684\u9694\u79bb\u7ea7\u522b\u4f1a\u9009\u7528\u8fd9\u4e2a\uff0c\u539f\u56e0\u5728\uff1a<\/p>\n<ul>\n<li>RR \u7ea7\u522b\u4e0b\uff0c\u5b58\u5728\u95f4\u6b47\u9501\uff0c\u51fa\u73b0\u6b7b\u9501\u7684\u51e0\u7387\u6bd4 RC \u5927\u7684\u591a<\/li>\n<li>RR \u7ea7\u522b\u4e0b\uff0c\u6761\u4ef6\u5217\u672a\u547d\u4e2d\u7d22\u5f15\u4f1a\u9501\u8868\u3002\u5728 RC \u7ea7\u522b\u4e0b\u4f1a\u9501\u884c<\/li>\n<li>RC \u7ea7\u522b\u4e0b\uff0c\u534a\u4e00\u81f4\u6027\u7279\u6027\u589e\u52a0\u4e86 update \u64cd\u4f5c\u7684\u5e76\u53d1\u6027<\/li>\n<\/ul>\n<p>\uff083\uff09\u53ef\u91cd\u590d\u8bfb\uff1a<\/p>\n<p>\u6570\u636e\u6821\u9a8c\uff1a\u5047\u8bbe\u4f60\u5728\u7ba1\u7406\u4e00\u4e2a\u4e2a\u4eba\u94f6\u884c\u8d26\u6237\u8868\u3002\u4e00\u4e2a\u8868\u5b58\u4e86\u6bcf\u4e2a\u6708\u6708\u5e95\u7684\u4f59\u989d\uff0c\u4e00\u4e2a\u8868\u5b58\u4e86\u8d26\u5355\u660e\u7ec6\u3002\u8fd9\u65f6\u5019\u4f60\u8981\u505a\u6570\u636e\u6821\u5bf9\uff0c\u4e5f\u5c31\u662f\u5224\u65ad\u4e0a\u4e2a\u6708\u7684\u4f59\u989d\u548c\u5f53\u524d\u4f59\u989d\u7684\u5dee\u989d\uff0c\u662f\u5426\u4e0e\u672c\u6708\u7684\u8d26\u5355\u660e\u7ec6\u4e00\u81f4\u3002\u4f60\u4e00\u5b9a\u5e0c\u671b\u5728\u6821\u5bf9\u8fc7\u7a0b\u4e2d\uff0c\u5373\u4f7f\u6709\u7528\u6237\u53d1\u751f\u4e86\u4e00\u7b14\u65b0\u7684\u4ea4\u6613\uff0c\u4e5f\u4e0d\u5f71\u54cd\u4f60\u7684\u6821\u5bf9\u7ed3\u679c\u3002\u8fd9\u65f6\u4f7f\u7528\u201c\u53ef\u91cd\u590d\u8bfb\u201d\u9694\u79bb\u7ea7\u522b\u5c31\u5f88\u65b9\u4fbf\u3002\u4e8b\u52a1\u542f\u52a8\u65f6\u7684\u89c6\u56fe\u53ef\u4ee5\u8ba4\u4e3a\u662f\u9759\u6001\u7684\uff0c\u4e0d\u53d7\u5176\u4ed6\u4e8b\u52a1\u66f4\u65b0\u7684\u5f71\u54cd\u3002<\/p>\n<p>\uff084\uff09\u4e32\u884c\u5316\uff1a<\/p>\n<p>\u6bcf\u6b21\u8bfb\u64cd\u4f5c\u90fd\u4f1a\u52a0\u9501\uff0c\u6027\u80fd\u4e0d\u4f73\u3002<\/p>\n<h3>\u4e8b\u52a1\u9694\u79bb\u7684\u5b9e\u73b0\uff1f<\/h3>\n<p>\u5728\u5b9e\u73b0\u4e0a\uff0c\u6570\u636e\u5e93\u91cc\u9762\u4f1a\u521b\u5efa\u4e00\u4e2a\u89c6\u56fe\uff0c\u8bbf\u95ee\u7684\u65f6\u5019\u4ee5\u89c6\u56fe\u7684\u903b\u8f91\u7ed3\u679c\u4e3a\u51c6\u3002<\/p>\n<ul>\n<li>\u5728\u53ef\u91cd\u590d\u8bfb\u65f6\u7684\u9694\u79bb\u7ea7\u522b\u4e0b\uff0c\u89c6\u56fe\u662f\u5728\u4e8b\u52a1\u542f\u52a8\u65f6\u521b\u5efa\u7684\uff0c\u6574\u4e2a\u4e8b\u52a1\u5b58\u5728\u671f\u95f4\u90fd\u4f1a\u7528\u8fd9\u4e2a\u89c6\u56fe<\/li>\n<li>\u5728\u8bfb\u63d0\u4ea4\u7684\u9694\u79bb\u7ea7\u522b\u4e0b\uff0c\u8fd9\u4e2a\u89c6\u56fe\u662f\u5728\u6bcf\u4e2a SQL \u8bed\u53e5\u5f00\u59cb\u6267\u884c\u65f6\u521b\u5efa\u7684<\/li>\n<li>\u5728\u8bfb\u672a\u63d0\u4ea4\u7684\u9694\u79bb\u7ea7\u522b\u4e0b\uff0c\u4f1a\u76f4\u63a5\u8fd4\u56de\u8bb0\u5f55\u7684\u6700\u65b0\u503c\uff0c\u6ca1\u6709\u89c6\u56fe\u7684\u6982\u5ff5<\/li>\n<li>\u4e32\u884c\u5316\u662f\u76f4\u63a5\u901a\u8fc7\u52a0\u9501\u7684\u65b9\u5f0f\u6765\u907f\u514d\u5e76\u884c\u8bbf\u95ee<\/li>\n<\/ul>\n<blockquote>\n<p>\u6ce8\u610f\u8fd9\u4e2a\u89c6\u56fe\u4e0d\u662f\u7528\u4e8e\u67e5\u8be2\u5b9a\u4e49\u7684\u865a\u62df\u8868\uff0c\u800c\u662f\u5728 InnoDB \u4e2d\u5b9e\u73b0 MVCC \u7528\u5230\u7684\u4e00\u81f4\u6027\u8bfb\u89c6\u56fe\uff08<code>consistent read view<\/code>\uff09\uff0c\u7528\u4e8e\u652f\u6301 RC \u548c RR \u9694\u79bb\u7ea7\u522b\u7684\u5b9e\u73b0\u3002<\/p>\n<\/blockquote>\n<p>\u53ef\u91cd\u590d\u8bfb\u7684\u5177\u4f53\u5b9e\u73b0\uff1a<\/p>\n<p>\u5728 MySQL \u4e2d\uff0c\u5b9e\u9645\u4e0a\u6bcf\u6761\u8bb0\u5f55\u5728\u66f4\u65b0\u65f6\u90fd\u4f1a\u540c\u65f6\u8bb0\u5f55\u4e00\u6761\u56de\u6eda\u64cd\u4f5c\u3002\u8bb0\u5f55\u4e0a\u4e00\u6b21\u7684\u6700\u65b0\u503c\uff0c\u901a\u8fc7\u56de\u6eda\u90fd\u53ef\u4ee5\u5f97\u5230\u524d\u4e00\u4e2a\u72b6\u6001\u7684\u503c\u3002\u6bd4\u5982\u4e00\u4e2a\u503c \u4ece 1 \u6309\u7167\u987a\u5e8f\uff0c\u88ab\u4fee\u6539\u6210 2\u30013\u30014 \uff0c\u5c31\u4f1a\u5728\u56de\u6eda\u65e5\u5fd7\u4e2d\u6709\u5982\u4e0b\u7684\u8bb0\u5f55\u3002<\/p>\n<p><img decoding=\"async\" src=\"http:\/\/www.yezhou.me\/AppBlog\/images\/\u6570\u636e\u5e93\/MySQL\u4e8b\u52a1-\u56de\u6eda\u8bb0\u5f55.png\" alt=\"MySQL\u4e8b\u52a1-\u56de\u6eda\u8bb0\u5f55\" \/><\/p>\n<p>\u5f53\u524d\u6700\u65b0\u662f 4\uff0c\u5728\u67e5\u8be2\u8fd9\u6761\u8bb0\u5f55\u65f6\uff0c\u4e0d\u540c\u65f6\u523b\u542f\u52a8\u7684\u4e8b\u52a1\u4f1a\u6709\u4e0d\u540c\u7684<code>read-view<\/code>\u3002\u5728\u89c6\u56fe A B C \u4e2d\uff0c\u8bb0\u5f55\u503c\u4e3a 1, 2, 4\u3002\u540c\u4e00\u6761\u8bb0\u5f55\u53ef\u4ee5\u5b58\u5728\u591a\u4e2a\u7248\u672c\uff0c\u8fd9\u5c31\u662f\u6570\u636e\u5e93\u591a\u7248\u672c\u5e76\u53d1\u63a7\u5236\uff08MVCC\uff09\u3002\u5bf9\u4e8e<code>read-view A<\/code>\u6765\u8bf4\uff0c\u8981\u5f97\u5230 1\uff0c\u5c31\u5fc5\u987b\u5c06\u5f53\u524d\u503c\u4f9d\u6b21\u6267\u884c\u56fe\u4e2d\u6240\u6709\u7684\u56de\u6eda\u64cd\u4f5c\u5f97\u5230\u3002\u5047\u5982\uff0c\u6709\u53e6\u5916\u4e00\u4e2a\u4e8b\u52a1\u5c06 4 \u6539\u6210 5\uff0c\u4f46\u5bf9\u4e8e\u89c6\u56fe A B C \u6765\u8bf4\uff0c\u4e8b\u52a1\u662f\u4e0d\u51b2\u7a81\u7684\u3002<\/p>\n<h2>\u56de\u6eda\u6bb5\u7684\u5220\u9664\uff0c\u4e3a\u4ec0\u4e48\u8981\u907f\u514d\u4f7f\u7528\u957f\u4e8b\u52a1\uff1f<\/h2>\n<p>\u65e2\u7136\u6bcf\u4e00\u6761\u8bb0\u5f55\u90fd\u4f1a\u66f4\u65b0\u662f\u90fd\u4f1a\u4ea7\u751f\u4e00\u6761\u56de\u6eda\u64cd\u4f5c\u8bb0\u5f55\uff0c\u65f6\u95f4\u4e00\u957f\uff0c\u80af\u5b9a\u4f1a\u5360\u7528\u5927\u91cf\u7684\u5b58\u50a8\u7a7a\u95f4\u3002\u90a3\u4e48\u7cfb\u7edf\u4f1a\u5728\u4ec0\u4e48\u65f6\u5019\u5220\u9664\u8fd9\u4e9b\u56de\u6eda\u65e5\u5fd7\u5462\uff0c\u5c31\u662f\u5728\u5f53\u524d\u7cfb\u7edf\u91cc\u4e0d\u5b58\u5728\u6bd4\u8be5\u56de\u6eda\u65e5\u5fd7\u66f4\u65e9\u7684<code>read-view<\/code>\u65f6\u3002<\/p>\n<p>\u4f46\u5982\u679c\u7cfb\u7edf\u91cc\u5b58\u5728\u7740\u5f88\u8001\u7684\u4e8b\u52a1\u89c6\u56fe\u3002\u7531\u4e8e\u8fd9\u4e9b\u4e8b\u52a1\u53ef\u80fd\u4f1a\u8bbf\u95ee\u6570\u636e\u5e93\u91cc\u7684\u4efb\u4f55\u6570\u636e\uff0c\u6240\u4ee5\u5728\u4e8b\u52a1\u63d0\u4ea4\u4e4b\u524d\uff0c\u6240\u6709\u53ef\u80fd\u7528\u5230\u7684\u56de\u6eda\u8bb0\u5f55\u90fd\u5fc5\u987b\u4fdd\u7559\uff0c\u8fd9\u5c31\u53ef\u80fd\u51fa\u73b0\u5360\u7528\u5927\u91cf\u5b58\u50a8\u7a7a\u95f4\u7684\u60c5\u51b5\u3002<\/p>\n<p>\u5728 MySQL 5.5 \u4e4b\u524d\uff0c\u56de\u6eda\u65e5\u5fd7\u548c\u6570\u636e\u5b57\u5178\u4e00\u8d77\u653e\u5728<code>ibdata<\/code>\u6587\u4ef6\u91cc\uff0c\u5373\u4f7f\u957f\u4e8b\u52a1\u88ab\u63d0\u4ea4\uff0c\u56de\u6eda\u6bb5\u88ab\u6e05\u7406\uff0c\u6587\u4ef6\u4e5f\u4e0d\u4f1a\u53d8\u5c0f\u3002<\/p>\n<p>\u5e76\u4e14\u957f\u4e8b\u52a1\u8fd8\u5360\u7528\u9501\u8d44\u6e90\uff0c\u4e5f\u53ef\u80fd\u62d6\u57ae\u6574\u4e2a\u5e93\u3002<\/p>\n<h2>MySQL \u4e2d\u4e8b\u52a1\u7684\u542f\u52a8\u65b9\u5f0f\uff1f<\/h2>\n<p>\u663e\u5f0f\u542f\u52a8\u4e8b\u52a1\uff1a<\/p>\n<pre><code class=\"language-sql\"># \u4f7f\u7528 START TRANSACTION \u6216\u8005 BEGIN \u5f00\u542f\u4e8b\u52a1\uff1a\nSTART TRANSACTION\n    [transaction_characteristic [, transaction_characteristic] ...]\n\ntransaction_characteristic: {\n    WITH CONSISTENT SNAPSHOT\n  | READ WRITE\n  | READ ONLY\n}\n\nBEGIN [WORK]\n\n# \u4f7f\u7528 COMMIT \u6765\u63d0\u4ea4\u4e8b\u52a1\nCOMMIT [WORK] [AND [NO] CHAIN] [[NO] RELEASE]\n\n# \u4f7f\u7528 ROLLBACK \u6765\u56de\u6eda\u4e8b\u52a1\nROLLBACK [WORK] [AND [NO] CHAIN] [[NO] RELEASE]<\/code><\/pre>\n<p>\u9690\u5f0f\u542f\u52a8\u4e8b\u52a1\uff1a<\/p>\n<pre><code class=\"language-sql\"># \u8bbe\u7f6e\u5f53\u524d\u4e8b\u52a1\u7684\u662f\u5426\u81ea\u52a8\u63d0\u4ea4\nSET autocommit = {0 | 1}<\/code><\/pre>\n<p>autocommit \u7684\u8ba8\u8bba\uff1a<\/p>\n<p>\uff081\uff09\u5f53<code>autocommit=0<\/code>\u65f6\uff0c\u4e8b\u52a1\u542f\u52a8\u540e\uff0c\u4e0d\u4f1a\u81ea\u52a8\u5173\u95ed\u76f4\u5230\u4e3b\u52a8\u7684\u8f93\u5165<code>COMMIT<\/code>\u6216\u8005<code>ROLLBACK<\/code>\u8bed\u53e5\uff0c\u6216\u8005\u65ad\u5f00\u8fde\u63a5\u65f6\uff0c\u5f53\u524d\u4e8b\u52a1\u624d\u7ed3\u675f<\/p>\n<p>\u4e00\u4e9b\u5ba2\u6237\u7aef\u8fde\u63a5\u6846\u67b6\u4f1a\u9ed8\u8ba4\u8fde\u63a5\u6210\u529f\u540e\u5148\u6267\u884c\u4e00\u4e2a<code>set autocommit=0<\/code>\u7684\u547d\u4ee4\u3002\u8fd9\u5c31\u5bfc\u81f4\u63a5\u4e0b\u6765\u7684\u67e5\u8be2\u90fd\u5728\u4e8b\u52a1\u4e2d\uff0c\u5982\u679c\u662f\u957f\u8fde\u63a5\uff0c\u5c31\u5bfc\u81f4\u4e86\u610f\u5916\u7684\u957f\u4e8b\u52a1\u3002<\/p>\n<p>\uff082\uff09\u5f53<code>autocommit=1<\/code>\u65f6\uff0c\u5efa\u8bae\u603b\u662f\u4ee5\u8fd9\u79cd\u65b9\u5f0f\u542f\u52a8\u4e8b\u52a1<\/p>\n<p>\u5982\u679c\u62c5\u5fc3\u591a\u4e00\u6b21\u4ea4\u4e92\u7684\u95ee\u9898\uff0c\u53ef\u4ee5\u4f7f\u7528<code>commit work and chain<\/code>\u8bed\u6cd5\u3002<\/p>\n<blockquote>\n<p>\u591a\u4e00\u6b21\u4ea4\u4e92\u7684\u95ee\u9898\uff0c\u5982\u679c\u91c7\u7528<code>autocommit=0<\/code>\u7684\u8fd9\u79cd\u65b9\u5f0f\uff0c\u4e0d\u9700\u8981\u6bcf\u6b21\u8f93\u5165<code>begin<\/code>\uff0c\u51cf\u5c11\u4e86\u8bed\u53e5\u7684\u4ea4\u4e92\u6b21\u6570\u3002<\/p>\n<\/blockquote>\n<p>\u67e5\u8be2\u957f\u4e8b\u52a1\uff1a<\/p>\n<pre><code class=\"language-sql\">select * from information_schema.innodb_trx where TIME_TO_SEC(timediff(now(),trx_started))&gt;60<\/code><\/pre>\n<p>\u907f\u514d\u957f\u4e8b\u52a1\u7684\u65b9\u6848\uff1a<\/p>\n<ul>\n<li>\u5728\u5f00\u53d1\u8fc7\u7a0b\u4e2d\uff0c\u51cf\u5c11\u4e8b\u52a1\u8303\u56f4\uff0c\u5c11\u7528\u957f\u4e8b\u52a1\u3002\u5982\u679c\u65e0\u6cd5\u907f\u514d\uff0c\u4fdd\u8bc1\u903b\u8f91\u65e5\u5fd7\u7a7a\u95f4\u591f\u7528\uff0c\u5e76\u4e14\u652f\u6301\u52a8\u6001\u65e5\u5fd7\u7a7a\u95f4\u7684\u589e\u957f<\/li>\n<li>\u76d1\u63a7<code>Innodb_trx<\/code>\u8868\uff0c\u53d1\u73b0\u957f\u4e8b\u52a1\u62a5\u8b66<\/li>\n<\/ul>\n<h2>\u603b\u7ed3<\/h2>\n<p>\u5728\u5f00\u59cb\u90e8\u5206\uff0c\u4ecb\u7ecd\u4e86 MySQL \u4e2d\u4e8b\u52a1\u7684\u6982\u5ff5\uff0c\u5e76\u56de\u987e\u4e86\u4e8b\u52a1\u7684 ACID \u7684\u7279\u6027\u3002\u63a5\u7740\u63a2\u8ba8\u4e86\u4e8b\u52a1\u9694\u79bb\u7684\u53ef\u80fd\u51fa\u73b0\u7684\u810f\u8bfb\uff0c\u4e0d\u53ef\u91cd\u590d\u8bfb\u4ee5\u53ca\u5e7b\u8bfb\u7684\u95ee\u9898\uff0c\u5e76\u7ed9\u51fa\u4e86\u76f8\u5e94\u7684\u89e3\u51b3\u65b9\u6848-\u9694\u79bb\u7ea7\u522b\u3002\u5e76\u5206\u6790\u4e86\u5e38\u89c1\u4e8b\u52a1\u9694\u79bb\u7684\u5e94\u7528\u573a\u666f\u4ee5\u53ca\u4e8b\u52a1\u9694\u79bb\u7684\u5b9e\u73b0\u65b9\u5f0f\u3002<\/p>\n<p>\u5e76\u5728\u6700\u540e\u5f15\u51fa\u4e86\u56de\u6eda\u6bb5\u7684\u6982\u5ff5\uff0c\u4ee5\u53ca\u4e3a\u4ec0\u4e48\u8981\u907f\u514d\u4f7f\u7528\u957f\u4e8b\u52a1\u3002\u5e76\u7ed9\u51fa\u4e86\u5f00\u542f\u4e8b\u52a1\u7684\u65b9\u6cd5\u3002<\/p>\n<blockquote>\n<p>\u8f6c\u8f7d\u81f3\uff1a<a target=\"_blank\" rel=\"noopener\" href=\"https:\/\/www.cnblogs.com\/michael9\/p\/11958199.html\">https:\/\/www.cnblogs.com\/michael9\/p\/11958199.html<\/a><\/p>\n<\/blockquote>\n","protected":false},"excerpt":{"rendered":"<p>MySQL \u4e2d\u7684\u4e8b\u52a1\uff1f \u5bf9 MySQL \u6765\u8bf4\uff0c\u4e8b\u52a1\u901a\u5e38\u662f\u4e00\u7ec4\u5305\u542b\u5bf9\u6570\u636e\u5e93\u64cd\u4f5c\u7684\u96c6\u5408\u3002\u5728\u6267\u884c\u65f6\uff0c\u53ea\u6709\u5728\u8be5\u7ec4\u5185\u7684\u4e8b [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[13],"tags":[87],"class_list":["post-2081","post","type-post","status-publish","format-standard","hentry","category-mysql","tag-87"],"_links":{"self":[{"href":"https:\/\/www.appblog.cn\/index.php\/wp-json\/wp\/v2\/posts\/2081","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=2081"}],"version-history":[{"count":0,"href":"https:\/\/www.appblog.cn\/index.php\/wp-json\/wp\/v2\/posts\/2081\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.appblog.cn\/index.php\/wp-json\/wp\/v2\/media?parent=2081"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.appblog.cn\/index.php\/wp-json\/wp\/v2\/categories?post=2081"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.appblog.cn\/index.php\/wp-json\/wp\/v2\/tags?post=2081"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}