{"id":200727,"date":"2025-05-06T11:43:20","date_gmt":"2025-05-06T03:43:20","guid":{"rendered":"https:\/\/server.hk\/cnblog\/200727\/"},"modified":"2025-05-06T11:43:20","modified_gmt":"2025-05-06T03:43:20","slug":"mysql-%e5%bf%ab%e7%85%a7%e8%af%bb%ef%bc%9a%e4%b8%ba%e4%bb%80%e4%b9%88-update-%e6%93%8d%e4%bd%9c%e5%90%8e-select-%e4%bc%9a%e8%bf%94%e5%9b%9e%e6%9c%80%e6%96%b0%e6%95%b0%e6%8d%ae%ef%bc%9f","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/200727\/","title":{"rendered":"MySQL \u5feb\u7167\u8bfb\uff1a\u4e3a\u4ec0\u4e48 UPDATE \u64cd\u4f5c\u540e SELECT \u4f1a\u8fd4\u56de\u6700\u65b0\u6570\u636e\uff1f"},"content":{"rendered":"

<\/b> <\/p>\n

MySQL \u5feb\u7167\u8bfb\uff1a\u4e3a\u4ec0\u4e48 UPDATE \u64cd\u4f5c\u540e SELECT \u4f1a\u8fd4\u56de\u6700\u65b0\u6570\u636e\uff1f<\/h1>\n

\u5c0f\u4f19\u4f34\u4eec\u6709\u6ca1\u6709\u89c9\u5f97\u5b66\u4e60\u5f88\u6709\u610f\u601d\uff1f\u6709\u610f\u601d\u5c31\u5bf9\u4e86\uff01\u4eca\u5929\u5c31\u7ed9\u5927\u5bb6\u5e26\u6765\uff0c\u4ee5\u4e0b\u5185\u5bb9\u5c06\u4f1a\u6d89\u53ca\u5230\uff0c\u82e5\u662f\u5728\u5b66\u4e60\u4e2d\u5bf9\u5176\u4e2d\u90e8\u5206\u77e5\u8bc6\u70b9\u6709\u7591\u95ee\uff0c\u6216\u8bb8\u770b\u4e86\u672c\u6587\u5c31\u80fd\u5e2e\u5230\u4f60\uff01<\/p>\n

<\/p>\n

MySQL\u7684\u5feb\u7167\u8bfb\u884c\u4e3a<\/strong><\/p>\n

\u5728MySQL\u4e2d\uff0c\u4e8b\u52a1\u9694\u79bb\u7684\u884c\u4e3a\u901a\u8fc7MVCC\uff08\u591a\u7248\u672c\u5e76\u53d1\u63a7\u5236\uff09\u673a\u5236\u5b9e\u73b0\uff0c\u8be5\u673a\u5236\u786e\u4fdd\u540c\u4e00\u6570\u636e\u4e0d\u4f1a\u88ab\u591a\u4e2a\u4e8b\u52a1\u540c\u65f6\u4fee\u6539\uff0c\u4ece\u800c\u5bfc\u81f4\u6570\u636e\u4e0d\u4e00\u81f4\u3002\u5728\u4e8b\u52a1\u9694\u79bb\u7ea7\u522b\u4e3aREPEATABLE READ\u7684\u60c5\u51b5\u4e0b\uff0c\u8bfb\u53d6\u64cd\u4f5c\u4f1a\u8fd4\u56de\u5f00\u59cb\u4e8b\u52a1\u65f6\u7684\u6570\u636e\u5feb\u7167\uff0c\u5373\u5176\u4ed6\u4e8b\u52a1\u7684\u4fee\u6539\u4e0d\u4f1a\u7acb\u5373\u88ab\u8bfb\u53d6\u5230\u3002<\/p>\n

\u5feb\u7167\u8bfb\u4e0eUPDATE\u7684\u5f71\u54cd<\/strong><\/p>\n

\u4f46\u6709\u4f8b\u5916\u60c5\u51b5\uff0c\u5f53\u4e00\u4e2a\u4e8b\u52a1\u6267\u884c\u4e86UPDATE\u64cd\u4f5c\u540e\uff0c\u540e\u7eed\u7684SELECT\u64cd\u4f5c\u53ef\u80fd\u4e0d\u4f1a\u518d\u8fd4\u56de\u5feb\u7167\u6570\u636e\u3002\u5728\u8fd9\u79cd\u60c5\u51b5\u4e0b\uff0cMySQL\u4f1a\u6839\u636e\u4ee5\u4e0b\u89c4\u5219\u51b3\u5b9a\u662f\u5426\u8fd4\u56de\u6700\u65b0\u6570\u636e\uff1a<\/p>\n

    \n
  1. \u88ab\u4fee\u6539\u7684\u884cID\u5fc5\u987b\u5927\u4e8e\u4e8b\u52a1\u7684m_up_limit_id\u3002<\/li>\n
  2. \u88ab\u4fee\u6539\u7684\u884cID\u5fc5\u987b\u5c0f\u4e8e\u6216\u7b49\u4e8e\u4e8b\u52a1\u7684m_low_limit_id\u3002<\/li>\n<\/ol>\n

    \u6848\u4f8b\u5206\u6790<\/strong><\/p>\n

    \u5728\u7ed9\u5b9a\u7684\u6848\u4f8b\u4e2d\uff0c\u4e8b\u52a1A\u6267\u884c\u4e86SELECT\u64cd\u4f5c\uff0c\u6ca1\u6709\u67e5\u5230ID\u4e3a5\u7684\u6570\u636e\uff0c\u56e0\u4e3a\u8be5\u6570\u636e\u88ab\u4e8b\u52a1B\u7684UPDATE\u64cd\u4f5c\u4fee\u6539\u4e86\u3002\u6309\u7167MVCC\u673a\u5236\uff0c\u4e8b\u52a1A\u7684\u540e\u7eedSELECT\u64cd\u4f5c\u5e94\u8be5\u4ecd\u7136\u65e0\u6cd5\u67e5\u5230\u8be5\u6570\u636e\uff0c\u56e0\u4e3a\u5b83\u4ecb\u4e8em_up_limit_id\uff08\u4e8b\u52a1A\u7684ID\uff09\u548cm_low_limit_id\uff08\u4e8b\u52a1B\u7684ID\u52a01\uff09\u4e4b\u95f4\u3002<\/p>\n

    \u5f02\u5e38\u884c\u4e3a\u7684\u539f\u56e0<\/strong><\/p>\n

    \u4f46\u5b9e\u9645\u4e0a\uff0c\u4e8b\u52a1A\u7684\u7b2c\u4e8c\u6b21SELECT\u64cd\u4f5c\u5374\u67e5\u5230\u4e86ID\u4e3a5\u7684\u6570\u636e\uff0c\u539f\u56e0\u662f\u6ee1\u8db3\u4e86\u4e0a\u8ff0\u89c4\u5219\u7684\u7b2c\u4e00\u6761\uff1a\u88ab\u4fee\u6539\u884c\u7684ID\uff085\uff09\u5927\u4e8e\u4e8b\u52a1A\u7684m_up_limit_id\uff08\u4e8b\u52a1A\u7684ID\uff09\uff0c\u56e0\u6b64MySQL\u8fd4\u56de\u4e86\u6700\u65b0\u6570\u636e\u3002<\/p>\n

    \u8fd9\u8868\u660e\u5728REPEATABLE READ\u9694\u79bb\u7ea7\u522b\u4e0b\uff0c\u5feb\u7167\u8bfb\u5e76\u975e\u5728\u4efb\u4f55\u60c5\u51b5\u4e0b\u90fd\u662f\u5b8c\u5168\u4e00\u81f4\u7684\uff0c\u5f53\u6ee1\u8db3\u7279\u5b9a\u89c4\u5219\u65f6\uff0cMySQL\u53ef\u80fd\u4f1a\u8fd4\u56de\u6700\u65b0\u6570\u636e\uff0c\u4ee5\u4fdd\u8bc1\u6570\u636e\u66f4\u53ca\u65f6\u5730\u53ef\u89c1\u3002<\/p>\n

    \u5230\u8fd9\u91cc\uff0c\u6211\u4eec\u4e5f\u5c31\u8bb2\u5b8c\u4e86\u300aMySQL \u5feb\u7167\u8bfb\uff1a\u4e3a\u4ec0\u4e48 UPDATE \u64cd\u4f5c\u540e SELECT \u4f1a\u8fd4\u56de\u6700\u65b0\u6570\u636e\uff1f\u300b\u7684\u5185\u5bb9\u4e86\u3002\u4e2a\u4eba\u8ba4\u4e3a\uff0c\u57fa\u7840\u77e5\u8bc6\u7684\u5b66\u4e60\u548c\u5de9\u56fa\uff0c\u662f\u4e3a\u4e86\u66f4\u597d\u7684\u5c06\u5176\u8fd0\u7528\u5230\u9879\u76ee\u4e2d\uff0c\u6b22\u8fce\u5173\u6ce8\u4e3b\u673a\u5b9d\u8d1d\u516c\u4f17\u53f7\uff0c\u5e26\u4f60\u4e86\u89e3\u66f4\u591a\u5173\u4e8e\u7684\u77e5\u8bc6\u70b9\uff01<\/p>\n

    \n
    \n <\/dt>\n<\/dl>\n","protected":false},"excerpt":{"rendered":"

    MySQL \u5feb\u7167\u8bfb\uff1a\u4e3a\u4ec0\u4e48 UP...<\/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-200727","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/200727","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=200727"}],"version-history":[{"count":0,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/200727\/revisions"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=200727"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=200727"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=200727"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}