{"id":4295,"date":"2019-06-06T15:55:17","date_gmt":"2019-06-06T07:55:17","guid":{"rendered":"http:\/\/www.xttblog.com\/?p=4295"},"modified":"2019-06-06T15:55:17","modified_gmt":"2019-06-06T07:55:17","slug":"%e9%98%bf%e9%87%8c%e7%9a%84%e5%87%a0%e4%b8%aa-mysql-%e9%9d%a2%e8%af%95%e9%a2%98%ef%bc%8c%e5%8f%8d%e6%ad%a3%e6%88%91%e6%98%af%e8%b7%aa%e4%ba%86%ef%bc%81","status":"publish","type":"post","link":"https:\/\/www.xttblog.com\/?p=4295","title":{"rendered":"\u963f\u91cc\u7684\u51e0\u4e2a MySQL \u9762\u8bd5\u9898\uff0c\u53cd\u6b63\u6211\u662f\u8dea\u4e86\uff01"},"content":{"rendered":"\n

\u6d4b\u8bd5\u662f\u6765\u8868\u660e bug \u7684\u5b58\u5728\u800c\u4e0d\u662f\u4e0d\u5b58\u5728\uff01\u540c\u6837\u7684\uff0c\u9762\u8bd5\u662f\u8bc1\u660e\u4f60\u6709\u7ecf\u9a8c\u800c\u4e0d\u662f\u4f60\u6ca1\u6709\u7ecf\u9a8c\uff01<\/p>\n\n\n\n

\u6628\u5929\uff0c\u5fae\u4fe1\u7fa4\u91cc\u6709\u4eba\u5728\u603b\u7ed3\u5b66\u4e60\u8fc7\u7a0b\uff0c\u5982\u679c\u8ba9\u5b66\u4e60\u66f4\u9ad8\u6548\u3002\u6709\u4eba\u8bf4\u505a\u7b14\u8bb0\uff0c\u6709\u4eba\u8bf4\u753b\u601d\u7ef4\u8111\u56fe\u3002\u3002\u3002\u800c\u6211\u5219\u559c\u6b22\u5237\u9762\u8bd5\u9898\u3002\u4e8e\u662f\u5728\u7fa4\u91cc\u6709\u4eba\u63d0\u95ee MySQL \u7684\u60c5\u51b5\u4e0b\uff0c\u6211\u627e\u4e86\u51e0\u9053\u5177\u8bf4\u662f\u963f\u91cc\u7684 MySQL \u9762\u8bd5\u9898\uff0c\u5927\u5bb6\u53ef\u4ee5\u501f\u52a9\u9ad8\u8003 + \u7aef\u5348\u7684\u7a7a\u95f2\u65f6\u95f4\u6765\u68c0\u9a8c\u4e00\u4e0b\u81ea\u5df1\uff01<\/p>\n\n\n\n

\"\"
\u6570\u636e\u5e93\u4f18\u5316\u6f0f\u6597\u6cd5\u5219<\/figcaption><\/figure><\/div>\n\n\n\n

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1\u3001\u7b80\u5355\u7684 select \u67e5\u8be2\uff0c\u5982\uff1aselect * from xttblog where id = 1; \u662f\u5c5e\u4e8e\u5feb\u7167\u8bfb\u5417\uff1f<\/p>\n\n\n\n

\u7b80\u5355\u7684 select \u64cd\u4f5c\uff0c\u5c5e\u4e8e\u5feb\u7167\u8bfb\uff0c\u4e0d\u52a0\u9501\u3002<\/p>\n\n\n\n

2\u3001\u5c5e\u4e8e\u5f53\u524d\u8bfb\u7684\u5e38\u89c1 SQL \u8bed\u53e5\u6709\u54ea\u4e9b\uff1f<\/p>\n\n\n\n

select * from xttblog where ? lock in share mode;\nselect * from xttblog where ? for update;\ninsert into xttblog values (\u2026);\nupdate xttblog set ? where ?;\ndelete from xttblog where ?;<\/code><\/pre>\n\n\n\n
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3\u3001\u5982\u679c id \u662f\u4e3b\u952e\uff0c\u4e14\u662f RC \u9694\u79bb\u7ea7\u522b\uff0cSQL\uff1adelete from xttblog where id = 10 \u4f1a\u52a0\u9501\u5417\uff1f<\/p>\n\n\n\n
\u4f1a\u52a0 X \u9501\uff0c\u6392\u5b83\u9501\u3002\u53ea\u9700\u8981\u5c06\u4e3b\u952e\u4e0a\uff0cid = 10 \u7684\u8bb0\u5f55\u52a0\u4e0a X \u9501\u5373\u53ef\u3002<\/p>\n\n\n\n
4\u3001\u95ee\u9898 3 \u79cd\u7684 id \u4e3b\u952e\u6539\u4e3a\u552f\u4e00\u7d22\u5f15\u540e\uff0cSQL\uff1adelete from xttblog where id = 10 \u4f1a\u52a0\u9501\u5417\uff1f<\/p>\n\n\n\n
\u82e5 id \u5217\u662f unique \u5217\uff0c\u5176\u4e0a\u6709 unique \u7d22\u5f15\u3002\u90a3\u4e48 SQL \u9700\u8981\u52a0\u4e24\u4e2a X \u9501\uff0c\u4e00\u4e2a\u5bf9\u5e94\u4e8e id unique \u7d22\u5f15\u4e0a\u7684 id = 10 \u7684\u8bb0\u5f55\uff0c\u53e6\u4e00\u628a\u9501\u5bf9\u5e94\u4e8e\u805a\u7c07\u7d22\u5f15\u4e0a\u7684\u76f8\u5bf9\u4e8e id unique \u5bf9\u5e94\u7684\u8bb0\u5f55\u3002<\/p>\n\n\n\n
5\u3001\u4e3b\u952e\u7d22\u5f15\u548c\u552f\u4e00\u7d22\u5f15\u7684\u533a\u522b\uff1f<\/p>\n\n\n\n
\u4e3b\u8981\u533a\u522b\u603b\u7ed3\u5982\u4e0b\uff1a\u4e3b\u952e\u662f\u4e00\u79cd\u7ea6\u675f\uff0c\u552f\u4e00\u7d22\u5f15\u662f\u4e00\u79cd\u7d22\u5f15\uff0c\u4e24\u8005\u5728\u672c\u8d28\u4e0a\u662f\u4e0d\u540c\u7684\u3002\u4e3b\u952e\u521b\u5efa\u540e\u4e00\u5b9a\u5305\u542b\u4e00\u4e2a\u552f\u4e00\u6027\u7d22\u5f15\uff0c\u552f\u4e00\u6027\u7d22\u5f15\u5e76\u4e0d\u4e00\u5b9a\u5c31\u662f\u4e3b\u952e\u3002\u552f\u4e00\u6027\u7d22\u5f15\u5217\u5141\u8bb8\u7a7a\u503c\uff0c\u800c\u4e3b\u952e\u5217\u4e0d\u5141\u8bb8\u4e3a\u7a7a\u503c\u3002\u4e3b\u952e\u5217\u5728\u521b\u5efa\u65f6\uff0c\u5df2\u7ecf\u9ed8\u8ba4\u4e3a\u7a7a\u503c + \u552f\u4e00\u7d22\u5f15\u4e86\u3002\u4e3b\u952e\u53ef\u4ee5\u88ab\u5176\u4ed6\u8868\u5f15\u7528\u4e3a\u5916\u952e\uff0c\u800c\u552f\u4e00\u7d22\u5f15\u4e0d\u80fd\u3002\u4e00\u4e2a\u8868\u6700\u591a\u53ea\u80fd\u521b\u5efa\u4e00\u4e2a\u4e3b\u952e\uff0c\u4f46\u53ef\u4ee5\u521b\u5efa\u591a\u4e2a\u552f\u4e00\u7d22\u5f15\u3002\u4e3b\u952e\u66f4\u9002\u5408\u90a3\u4e9b\u4e0d\u5bb9\u6613\u66f4\u6539\u7684\u552f\u4e00\u6807\u8bc6\uff0c\u5982\u81ea\u52a8\u9012\u589e\u5217\u3001\u8eab\u4efd\u8bc1\u53f7\u7b49\u3002\u5728 RBO \u6a21\u5f0f\u4e0b\uff0c\u4e3b\u952e\u7684\u6267\u884c\u8ba1\u5212\u4f18\u5148\u7ea7\u8981\u9ad8\u4e8e\u552f\u4e00\u7d22\u5f15\u3002 \u4e24\u8005\u53ef\u4ee5\u63d0\u9ad8\u67e5\u8be2\u7684\u901f\u5ea6\u3002<\/p>\n\n\n\n
6\u3001\u552f\u4e00\u6027\u592a\u5dee\u7684\u5b57\u6bb5\u4e0d\u5b9c\u5efa\u7acb\u7d22\u5f15\u7684\u539f\u56e0\u662f\u4ec0\u4e48\uff1f<\/p>\n\n\n\n
\u56e0\u4e3amysql\u9996\u5148\u4f1a\u5c06\u7d22\u5f15\u4e2d\u7684\u952e\u503c\u53d6\u51fa\u6765\u4e0e\u5185\u5b58\u4e2d\u5b58\u50a8\u8868\u6570\u636e\u7684\u9875\u4e2d\u7684\u6570\u636e\u76f8\u6bd4\u8f83\uff0c\u4f46\u662f\u6570\u636e\u9875\u4e2d\u7684\u6570\u636e\u7684\u987a\u5e8f\u548c\u7d22\u5f15\u961f\u5217\u4e2d\u952e\u503c\u7684\u987a\u5e8f\u5e76\u4e0d\u662f\u4e00\u81f4\u7684\u3002\u5047\u5982\u7d22\u5f15\u4e2d\u7684\u952e\u503c a \u5148\u5728\u6570\u636e\u9875x\u4e2d\u627e\u5230\u4e86\u7b26\u5408\u7684\u6570\u636e\uff0c\u7136\u540e\u53c8\u5728\u6570\u636e\u9875 y \u4e2d\u627e\u5230\u4e86\u7b26\u5408\u6761\u4ef6\u7684\u6570\u636e\uff0c\u8fd9\u65f6 mysql \u4fbf\u4f1a\u628a\u6570\u636e\u9875 x \u9500\u6bc1\u6389\uff0c\u628a\u6570\u636e\u9875 Y \u8bfb\u5230\u5185\u5b58\u4e2d\u3002\u5982\u679c\u8fd9\u65f6\u5019\u8fd8\u6709\u952e\u503c b\uff0c\u7136\u540e\u952e\u503c b \u627e\u7684\u6570\u636e\u53c8\u5728\u6570\u636e\u9875 x \u4e0a\uff0c\u5219 mysql \u53c8\u8981\u628a\u6570\u636e\u9875 x \u8bfb\u5230\u5185\u5b58\u4e2d\u3002\u4e5f\u5c31\u662f\u8bf4\u4ece\u7d22\u5f15\u53bb\u5bfb\u627e\u5bf9\u5e94\u7684\u8868\u6570\u636e\u7684\u65f6\u5019\u662f\u968f\u673a\u8bbf\u95ee\u7684\u3002\uff08\u5b9e\u9645\u60c5\u51b5\u5e94\u8be5\u662f\u5185\u5b58\u4e2d\u7f13\u5b58\u4e86\u597d\u51e0\u9875\u7684\u6570\u636e\uff0c\u5e94\u8be5\u4e0d\u53ea\u4e00\u9875\uff0c\u4f46\u662f\u8fd9\u91cc\u5047\u5b9a\u7ebf\u7a0b\u5185\u5b58\u4e2d\u53ea\u5b58\u5728\u4e00\u5f20\u9875\u8868\uff09\u3002\u8fd9\u6837\u7684\u968f\u673a\u8bbf\u95ee\u6240\u9020\u6210\u7684 io \u6d88\u8017\u662f\u6bd4\u5168\u8868\u626b\u63cf\u7684 io \u6d88\u8017\u6765\u5f97\u5927\u7684\uff0c\u8fd8\u4e0d\u5982\u904d\u5386\u6574\u5f20\u8868\u3002<\/p>\n\n\n\n
\u4e3e\u4e2a\u6781\u7aef\u7684\u4f8b\u5b50\u3002\u8868 xttblog(ID,col1,col2,col3,col4,..col100) \u5171 100 \u4e2a\u5b57\u6bb5\uff0c\u73b0\u5728 COL4 \u4e0a\u521b\u5efa\u7d22\u5f15\uff0c\u800c COL4 \u4e2d\u6240\u6709\u7684\u503c\u90fd\u4e3a 1\uff0cupdate a set col4 = 1\uff0c10000 \u6761\u8bb0\u5f55\uff0cCOL4 \u90fd\u662f 1\u3002\u5982\u679c\u4f60\u67e5\u8be2 select * from xttblog where col4 = 1; MYSQL \u5c31\u4e0d\u4f1a\u518d\u53bb\u8d70\u7d22\u5f15\u3002 \u56e0\u4e3a\u5982\u679c\u8d70\u7d22\u5f15\u53cd\u800c\u901f\u5ea6\u6162\u3002 MYSQL \u4f1a\u81ea\u884c\u5224\u65ad\u662f\u5426\u9700\u8981\u4f7f\u7528\u7d22\u5f15\u3002\u8fd9\u4e5f\u662f\u4e3a\u4ec0\u4e48\u7ecf\u5e38\u4f1a\u770b\u5230 EXPLAIN \u4e2d\u660e\u660e\u6709\u7d22\u5f15\uff0c\u4f46\u5e76\u672a\u88ab\u4f7f\u7528\u3002\u540c\u6837\uff0c\u5373\u4f7f update xttblog set col4 = 0 where id = 10\uff0c\u8fd9\u6837\uff0c \u4ec5 ID = 10\u7684\u8bb0\u5f55 COL4 = 0\uff0c\u800c\u5176\u4f59 9999 \u6761\u8bb0\u5f55\u4ecd\u662f COL4 = 1\u3002 \u540c\u6837 select * from A where col4=1; \u5982\u679c\u6b64\u65f6\u53bb\u8d70\u7d22\u5f15\u5f00\u9500\u540c\u6837 \u6bd4\u4e0d\u8d70\u7d22\u5f15\u8981\u5927\u3002<\/p>\n\n\n\n
\u7efc\u4e0a\uff0c\u552f\u4e00\u6027\u592a\u5dee\u7684\u5b57\u6bb5\u4e0d\u5b9c\u5efa\u7acb\u7d22\u5f15\u3002<\/p>\n
\"\u4e1a\u4f59\u8349\u516c\u4f17\u53f7\"\/<\/p>
\u6700\u540e\uff0c\u6b22\u8fce\u5173\u6ce8\u6211\u7684\u4e2a\u4eba\u5fae\u4fe1\u516c\u4f17\u53f7\uff1a\u4e1a\u4f59\u8349\uff08yyucao\uff09\uff01\u53ef\u52a0\u4f5c\u8005\u5fae\u4fe1\u53f7\uff1axttblog2<\/font>\u3002\u5907\u6ce8\uff1a\u201c1\u201d\uff0c\u6dfb\u52a0\u535a\u4e3b\u5fae\u4fe1\u62c9\u4f60\u8fdb\u5fae\u4fe1\u7fa4\u3002\u5907\u6ce8\u9519\u8bef\u4e0d\u4f1a\u540c\u610f\u597d\u53cb\u7533\u8bf7\u3002<\/b>\u518d\u6b21\u611f\u8c22\u60a8\u7684\u5173\u6ce8\uff01\u540e\u7eed\u6709\u7cbe\u5f69\u5185\u5bb9\u4f1a\u7b2c\u4e00\u65f6\u95f4\u53d1\u7ed9\u60a8\uff01\u539f\u521b\u6587\u7ae0\u6295\u7a3f\u8bf7\u53d1\u9001\u81f3532009913@qq.com\u90ae\u7bb1\u3002\u5546\u52a1\u5408\u4f5c\u4e5f\u53ef\u6dfb\u52a0\u4f5c\u8005\u5fae\u4fe1\u8fdb\u884c\u8054\u7cfb\uff01<\/p>
\u672c\u6587\u539f\u6587\u51fa\u5904\uff1a\u4e1a\u4f59\u8349<\/a>\uff1a » \u963f\u91cc\u7684\u51e0\u4e2a MySQL \u9762\u8bd5\u9898\uff0c\u53cd\u6b63\u6211\u662f\u8dea\u4e86\uff01<\/a><\/p>","protected":false},"excerpt":{"rendered":"
\u6d4b\u8bd5\u662f\u6765\u8868\u660e bug \u7684\u5b58\u5728\u800c\u4e0d\u662f\u4e0d\u5b58\u5728\uff01\u540c\u6837\u7684\uff0c\u9762\u8bd5\u662f\u8bc1\u660e\u4f60\u6709\u7ecf\u9a8c\u800c\u4e0d\u662f\u4f60\u6ca1\u6709\u7ecf\u9a8c\uff01 \u6628\u5929\uff0c\u5fae\u4fe1\u7fa4\u91cc\u6709\u4eba\u5728\u603b […]<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[12],"tags":[386,83,106,410,723],"class_list":["post-4295","post","type-post","status-publish","format-standard","hentry","category-sql","tag-java","tag-mysql","tag-106","tag-410","tag-723"],"_links":{"self":[{"href":"https:\/\/www.xttblog.com\/index.php?rest_route=\/wp\/v2\/posts\/4295","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.xttblog.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.xttblog.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.xttblog.com\/index.php?rest_route=\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.xttblog.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=4295"}],"version-history":[{"count":1,"href":"https:\/\/www.xttblog.com\/index.php?rest_route=\/wp\/v2\/posts\/4295\/revisions"}],"predecessor-version":[{"id":4296,"href":"https:\/\/www.xttblog.com\/index.php?rest_route=\/wp\/v2\/posts\/4295\/revisions\/4296"}],"wp:attachment":[{"href":"https:\/\/www.xttblog.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=4295"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.xttblog.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=4295"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.xttblog.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=4295"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}