{"id":2323,"date":"2022-03-13T23:52:43","date_gmt":"2022-03-13T15:52:43","guid":{"rendered":"https:\/\/www.zeroheart.xyz\/wordpress\/?p=2323"},"modified":"2022-03-13T23:56:48","modified_gmt":"2022-03-13T15:56:48","slug":"%e6%82%b2%e8%a7%82%e9%94%81","status":"publish","type":"post","link":"https:\/\/www.zeroheart.xyz\/wordpress\/?p=2323","title":{"rendered":"\u60b2\u89c2\u9501"},"content":{"rendered":"\n<p><a href=\"https:\/\/www.cnblogs.com\/Alandre\/p\/4357190.html\">JavaWeb \u5e76\u53d1\uff1aFOR UPDATE \u5b9e\u6218\uff0c\u76d1\u6d4b\u5e76\u89e3\u51b3\u3002 &#8211; \u7a0b\u5e8f\u5458\u6ce5\u74e6\u5320 &#8211; \u535a\u5ba2\u56ed (cnblogs.com)<\/a><\/p>\n\n\n\n<p>\u4ee5\u4e0a\u6587\u7ae0\u662f\u4e00\u4e2a\u5177\u4f53\u7684\u4f8b\u5b50 <\/p>\n\n\n\n<p>\u5047\u8bbe\u6709\u4e2a\u8868table\uff0cf1\uff0cf2\uff0cf3\u4e09\u4e2a\u5b57\u6bb5\uff0c\u6211\u4eec\u8981\u505a\u7684\u4e8b<\/p>\n\n\n\n<p>1.select * from a where id = x;<\/p>\n\n\n\n<p>2.update a set f1=f1+10, f2=f2-20, f3=f3+30 where id = xx;<\/p>\n\n\n\n<p>3.\u63d0\u9ad8\u5e76\u53d1\u6570\u91cf<\/p>\n\n\n\n<p>\u4ee5\u4e0a\u5904\u7406\uff0c\u5728\u5e76\u53d1\u5927\u7684\u65f6\u5019\uff0c\u53ef\u4ee5\u62a5\u6570\u636e\u5e93\u7684\u8fde\u63a5\u9519\u8bef\uff0c\u4e5f\u53ef\u80fd\u51fa\u73b0\u6570\u636ef1,f2,f3\u4e0d\u7b26\u5408\u6211\u4eec\u9884\u60f3\u7684\u60c5\u51b5<\/p>\n\n\n\n<p>\u53ef\u4ee5\u4f7f\u7528for update\u6765\u5904\u7406\uff0c\u4f7f\u7528\u60b2\u89c2\u9501\u4e4b\u540e\uff0c\u5728\u89e3\u9501\u4e4b\u524d\uff0c\u5176\u4ed6\u4e8b\u52a1\u4e0d\u80fd\u4fee\u6539\u9501\u4f4f\u7684\u6570\u636e\u3002<\/p>\n\n\n\n<pre class=\"wp-block-preformatted\">https:\/\/zhuanlan.zhihu.com\/p\/74875550\n\nfor update \u7684\u4f5c\u7528\u548c\u76ee\u7684\uff1a\nselect for update \u662f\u4e3a\u4e86\u5728\u67e5\u8be2\u65f6,\u5bf9\u8fd9\u6761\u6570\u636e\u8fdb\u884c\u52a0\u9501,\u907f\u514d\u5176\u4ed6\u7528\u6237\u4ee5\u8be5\u8868\u8fdb\u884c\u63d2\u5165,\u4fee\u6539\u6216\u5220\u9664\u7b49\u64cd\u4f5c,\u9020\u6210\u8868\u7684\u4e0d\u4e00\u81f4\u6027.\n\n\u51e0\u4e2a\u7c7b\u4f3c\u7684\u573a\u666f\uff1a\n\nselect * from t for update \u4f1a\u7b49\u5f85\u884c\u9501\u91ca\u653e\u4e4b\u540e\uff0c\u8fd4\u56de\u67e5\u8be2\u7ed3\u679c\u3002\nselect * from t for update nowait \u4e0d\u7b49\u5f85\u884c\u9501\u91ca\u653e\uff0c\u63d0\u793a\u9501\u51b2\u7a81\uff0c\u4e0d\u8fd4\u56de\u7ed3\u679c\nselect * from t for update wait 5 \u7b49\u5f855\u79d2\uff0c\u82e5\u884c\u9501\u4ecd\u672a\u91ca\u653e\uff0c\u5219\u63d0\u793a\u9501\u51b2\u7a81\uff0c\u4e0d\u8fd4\u56de\u7ed3\u679c\nselect * from t for update skip locked \u67e5\u8be2\u8fd4\u56de\u67e5\u8be2\u7ed3\u679c\uff0c\u4f46\u5ffd\u7565\u6709\u884c\u9501\u7684\u8bb0\u5f55\nSELECT...FOR UPDATE \u8bed\u53e5\u7684\u8bed\u6cd5\u5982\u4e0b\uff1a\n\u3000\u3000SELECT ... FOR UPDATE [OF column_list][WAIT n|NOWAIT][SKIP LOCKED];\n\u5176\u4e2d\uff1a\n\u3000\u3000OF \u5b50\u53e5\u7528\u4e8e\u6307\u5b9a\u5373\u5c06\u66f4\u65b0\u7684\u5217\uff0c\u5373\u9501\u5b9a\u884c\u4e0a\u7684\u7279\u5b9a\u5217\u3002\n\u3000\u3000WAIT \u5b50\u53e5\u6307\u5b9a\u7b49\u5f85\u5176\u4ed6\u7528\u6237\u91ca\u653e\u9501\u7684\u79d2\u6570\uff0c\u9632\u6b62\u65e0\u9650\u671f\u7684\u7b49\u5f85\u3002\n\n\u201c\u4f7f\u7528FOR UPDATE WAIT\u201d\u5b50\u53e5\u7684\u4f18\u70b9\u5982\u4e0b\uff1a\n\u3000\u30001\u9632\u6b62\u65e0\u9650\u671f\u5730\u7b49\u5f85\u88ab\u9501\u5b9a\u7684\u884c\uff1b\n\u3000\u30002\u5141\u8bb8\u5e94\u7528\u7a0b\u5e8f\u4e2d\u5bf9\u9501\u7684\u7b49\u5f85\u65f6\u95f4\u8fdb\u884c\u66f4\u591a\u7684\u63a7\u5236\u3002\n\u3000\u30003\u5bf9\u4e8e\u4ea4\u4e92\u5f0f\u5e94\u7528\u7a0b\u5e8f\u975e\u5e38\u6709\u7528\uff0c\u56e0\u4e3a\u8fd9\u4e9b\u7528\u6237\u4e0d\u80fd\u7b49\u5f85\u4e0d\u786e\u5b9a\n\u3000\u30004 \u82e5\u4f7f\u7528\u4e86skip locked\uff0c\u5219\u53ef\u4ee5\u8d8a\u8fc7\u9501\u5b9a\u7684\u884c\uff0c\u4e0d\u4f1a\u62a5\u544a\u7531wait n \u5f15\u53d1\u7684\u2018\u8d44\u6e90\u5fd9\u2019\u5f02\u5e38\u62a5\u544a<\/pre>\n\n\n\n<p>\u5f53\u7136\uff0c\u5f88\u591a\u65f6\u5019\u6211\u4eec\u6570\u636e\u662f<strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-bright-red-color\">\u591a\u8bfb\u5c11\u5199<\/mark><\/strong>\u7684\uff0c\u5982svn\u3001git\u7b49\u6a21\u5f0f\uff0c\u76f4\u63a5\u4f7f\u7528\u4e50\u89c2\u9501\uff0c\u65e2\u589e\u52a0\u7248\u672c\u6216\u8005\u6bd4\u8f83\u5f53\u524d\u503c\u7b49\u65b9\u5f0f\u6765\u66f4\u65b0\u6570\u636e\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>JavaWeb \u5e76\u53d1\uff1aFOR UPDATE \u5b9e\u6218\uff0c\u76d1\u6d4b\u5e76\u89e3\u51b3\u3002 &#8211; \u7a0b\u5e8f\u5458\u6ce5\u74e6\u5320 &#8211;  [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[12],"tags":[],"_links":{"self":[{"href":"https:\/\/www.zeroheart.xyz\/wordpress\/index.php?rest_route=\/wp\/v2\/posts\/2323"}],"collection":[{"href":"https:\/\/www.zeroheart.xyz\/wordpress\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.zeroheart.xyz\/wordpress\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.zeroheart.xyz\/wordpress\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.zeroheart.xyz\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=2323"}],"version-history":[{"count":6,"href":"https:\/\/www.zeroheart.xyz\/wordpress\/index.php?rest_route=\/wp\/v2\/posts\/2323\/revisions"}],"predecessor-version":[{"id":2330,"href":"https:\/\/www.zeroheart.xyz\/wordpress\/index.php?rest_route=\/wp\/v2\/posts\/2323\/revisions\/2330"}],"wp:attachment":[{"href":"https:\/\/www.zeroheart.xyz\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=2323"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.zeroheart.xyz\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=2323"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.zeroheart.xyz\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=2323"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}