{"id":17814,"date":"2025-04-06T10:18:55","date_gmt":"2025-04-06T02:18:55","guid":{"rendered":"https:\/\/www.orczhou.com\/?p=17814"},"modified":"2025-04-07T08:18:57","modified_gmt":"2025-04-07T00:18:57","slug":"innodb-integer-sign-bit-mysql","status":"publish","type":"post","link":"https:\/\/www.orczhou.com\/index.php\/2025\/04\/innodb-integer-sign-bit-mysql\/","title":{"rendered":"InnoDB \u6574\u6570\u7c7b\u578b\u5b58\u50a8\u7684sign bit\u7684\u8bbe\u7f6e"},"content":{"rendered":"<div id=\"tocer-1\" class=\"tocer tocer-pos-flt-e\"><div class=\"tocer-toc\"><header class=\"tocer-header\"><h2 class=\"tocer-title\">\u76ee\u5f55<\/h2>\n<\/header>\n<ul class=\"tocer-list tocer-adv tocer-sp-os-bf tocer-st-ctrs-dec tocer-lvl1\"><li><div><a href=\"#tocer-heading-1\">InnoDB \u7684\u6574\u6570\u5b58\u50a8<\/a><\/div><\/li>\n<li><div><a href=\"#tocer-heading-2\">\u8003\u8651 8-bit \u573a\u666f\u4e0b\u7684<\/a><\/div><\/li>\n<li><div><a href=\"#tocer-heading-3\">\u9a8c\u8bc1\u5b58\u50a8\u65b9\u5f0f<\/a><\/div><\/li>\n<li><div><a href=\"#tocer-heading-4\">\u4ec0\u4e48\u8981\u8fd9\u4e48\u5b58\u50a8<\/a><\/div><\/li>\n<li><div><a href=\"#tocer-heading-5\">\u5173\u4e8e\u8865\u7801<\/a><\/div><\/li>\n<li><div><a href=\"#tocer-heading-6\">\u8865\u5145\u8bf4\u660e<\/a><\/div><\/li>\n<li><div><a href=\"#tocer-heading-7\">\u53c2\u8003\u6587\u6863<\/a><\/div><\/li>\n<\/ul>\n<\/div><\/div>\n\n\n\n<p>\u5b58\u50a8\u5f15\u64ce\u5728\u5b58\u50a8\u6574\u6570\u65f6\uff0c\u4e00\u822c\u4f1a\u4f7f\u7528\u6700\u9ad8\u4f4d\u4f5c\u4e3a\u6807\u5fd7\u4f4d\uff0c\u6807\u8bb0\u5b58\u50a8\u7684\u6574\u6570\u662f\u6b63\u6570\u8fd8\u662f\u8d1f\u6570\uff08<a href=\"https:\/\/en.wikipedia.org\/wiki\/Bit_numbering\">\u53c2\u8003<\/a>\uff09\uff0c\u6700\u9ad8\u4f4d\u4e5f\u88ab\u79f0\u4e3a\u201cmost significant bit (MSb)\u201d\u3002\u901a\u5e38\uff0c\u6700\u9ad8\u4f4d\u4e3a<code>1<\/code>\u5219\u8868\u793a\u6b63\u6570\uff0c\u6700\u9ad8\u4f4d\u4e3a<code>0<\/code>\uff0c\u5219\u8868\u793a\u8d1f\u6570\u3002\u66f4\u8fdb\u4e00\u6b65\u7684\uff0c\u8d1f\u6570\u5219\u4f1a\u901a\u8fc7\u8865\u7801\uff08\u53c2\u8003\uff1a<a href=\"https:\/\/en.wikipedia.org\/wiki\/Two%27s_complement\">two&#8217;s complement<\/a>\uff09\u7684\u65b9\u5f0f\u8868\u793a\u3002\u4f46\u662f\uff0cInnoDB\u6ca1\u6709\u4f7f\u7528\u8fd9\u79cd\u65b9\u6cd5\u3002<\/p>\n\n\n\n<h4 class=\"wp-block-heading\">InnoDB \u7684\u6574\u6570\u5b58\u50a8<\/h4>\n\n\n\n<div class=\"wp-block-columns is-layout-flex wp-container-core-columns-is-layout-28f84493 wp-block-columns-is-layout-flex\">\n<div class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\">\n<p>\u5728\u6b7b\u9501\u8bca\u65ad\u65f6\uff0c\u5076\u7136\u6ce8\u610f\u5230\uff0cInnoDB \u5728\u5b58\u50a8\u6574\u6570\u65f6\uff0c\u4e0e\u4e00\u822c\u7684\u7cfb\u7edf\u662f\u4e0d\u540c\u7684\u3002\u4f8b\u5982\uff0cint \u7c7b\u578b\u5b58\u50a8 1 \u7684\u65f6\u5019\uff0c\u4f7f\u7528\u7684\u8868\u793a\u662f\uff1a<code>0x80000001<\/code>\u3002\u66f4\u591a\u7684\u793a\u4f8b\u53ef\u4ee5\u53c2\u8003\u53f3\u56fe\uff1a<\/p>\n<\/div>\n\n\n\n<div class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\">\n<figure class=\"wp-block-table is-style-regular\"><table class=\"has-fixed-layout\"><thead><tr><th class=\"has-text-align-center\" data-align=\"center\">\u6574\u6570\u503c<\/th><th class=\"has-text-align-center\" data-align=\"center\">InnoDB \u8868\u793a<\/th><\/tr><\/thead><tbody><tr><td class=\"has-text-align-center\" data-align=\"center\"><code>1<\/code><\/td><td class=\"has-text-align-center\" data-align=\"center\"><code>0x80000001<\/code><\/td><\/tr><tr><td class=\"has-text-align-center\" data-align=\"center\"><code>-1<\/code><\/td><td class=\"has-text-align-center\" data-align=\"center\"><code>0x7fffffff<\/code><\/td><\/tr><tr><td class=\"has-text-align-center\" data-align=\"center\"><code>7<\/code><\/td><td class=\"has-text-align-center\" data-align=\"center\"><code>0x80000007<\/code><\/td><\/tr><tr><td class=\"has-text-align-center\" data-align=\"center\"><code>-7<\/code><\/td><td class=\"has-text-align-center\" data-align=\"center\"><code>0x7ffffff9<\/code><\/td><\/tr><\/tbody><\/table><\/figure>\n<\/div>\n<\/div>\n\n\n\n<p>\u53ef\u4ee5\u770b\u5230\uff0c\u8fd9\u4e0e\u4e00\u822c\u7684\u6709\u7b26\u53f7\u578b\u7684\u6574\u6570\u5b58\u50a8\u662f\u76f8\u53cd\u7684\u3002\u5373\uff1a<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u6b63\u6570\u8868\u793a\u65f6\uff0c\u6700\u9ad8\u4f4d\uff08MSb\uff09\u4e3a<code>1<\/code><\/li>\n\n\n\n<li>\u8d1f\u6570\u8868\u793a\u65f6\uff0c\u6700\u9ad8\u4f4d\uff08MSb\uff09\u4e3a<code>0<\/code><\/li>\n<\/ul>\n\n\n\n<p>\u5173\u4e8e\u8fd9\u4e2a\u95ee\u9898\uff0c\u5728 <code>Stackoverflow<\/code>\u4e0a\u4e5f\u6709\u770b\u5230\u6709\u90e8\u5206\u7528\u6237\u6709\u7c7b\u4f3c\u7684\u7591\u95ee\uff1a<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><a href=\"https:\/\/stackoverflow.com\/questions\/66940648\/mysql-highest-bit-whether-is-1-or-0-when-column-is-designed-signed-int\">mysql highest bit Whether is 1 or 0 , when column is designed signed int<\/a> <\/li>\n\n\n\n<li><a href=\"https:\/\/stackoverflow.com\/questions\/62494775\/how-mysql-represent-twos-complement\">how mysql represent two&#8217;s complement<\/a><\/li>\n<\/ul>\n\n\n\n<p>\u672c\u6587\u5c06\u8ba8\u8bba\u4e3a\u4ec0\u4e48\u4f1a\u8fd9\u6837\u3002<\/p>\n\n\n\n<h4 class=\"wp-block-heading\">\u8003\u8651 8-bit \u573a\u666f\u4e0b\u7684<\/h4>\n\n\n\n<p>\u8fd9\u91cc\u6765\u56de\u987e\u4e00\u4e0b\u201c\u4f53\u7cfb\u7ed3\u6784\u201d\u4e2d\u7684\u6700\u4e3a\u57fa\u7840\u7684\u4e00\u4e9b\u77e5\u8bc6\u5427\u3002<\/p>\n\n\n\n<figure class=\"wp-block-table is-style-regular\"><table><thead><tr><th class=\"has-text-align-center\" data-align=\"center\">\u6574\u6570\u503c<\/th><th class=\"has-text-align-center\" data-align=\"center\">\u7edd\u5bf9\u503c<\/th><th class=\"has-text-align-center\" data-align=\"center\">\u7edd\u5bf9\u503c\u7684\u4e8c\u8fdb\u5236<\/th><th class=\"has-text-align-center\" data-align=\"center\">\u539f\u7801<\/th><th>2-\u8865\u7801<\/th><th class=\"has-text-align-center\" data-align=\"center\">Offset binary\uff08\u201c\u79fb\u7801\u201d\uff09<\/th><\/tr><\/thead><tbody><tr><td class=\"has-text-align-center\" data-align=\"center\"><code>1<\/code><\/td><td class=\"has-text-align-center\" data-align=\"center\"><code>1<\/code><\/td><td class=\"has-text-align-center\" data-align=\"center\"><code>0000-0001<\/code><\/td><td class=\"has-text-align-center\" data-align=\"center\"><code>0000-0001<\/code><\/td><td><code>0000-0001<\/code><\/td><td class=\"has-text-align-center\" data-align=\"center\"><code>1000-0001<\/code><\/td><\/tr><tr><td class=\"has-text-align-center\" data-align=\"center\"><code>-1<\/code><\/td><td class=\"has-text-align-center\" data-align=\"center\"><code>1<\/code><\/td><td class=\"has-text-align-center\" data-align=\"center\"><code>0000-0001<\/code><\/td><td class=\"has-text-align-center\" data-align=\"center\"><code>1000-0001<\/code><\/td><td><code>1111-1111<\/code><\/td><td class=\"has-text-align-center\" data-align=\"center\"><code>0111-1111<\/code><\/td><\/tr><tr><td class=\"has-text-align-center\" data-align=\"center\"><code>7<\/code><\/td><td class=\"has-text-align-center\" data-align=\"center\"><code>7<\/code><\/td><td class=\"has-text-align-center\" data-align=\"center\"><code>0000-0111<\/code><\/td><td class=\"has-text-align-center\" data-align=\"center\"><code>0000-0111<\/code><\/td><td><code>0000-0111<\/code><\/td><td class=\"has-text-align-center\" data-align=\"center\"><code>1000-0111<\/code><\/td><\/tr><tr><td class=\"has-text-align-center\" data-align=\"center\"><code>-7<\/code><\/td><td class=\"has-text-align-center\" data-align=\"center\"><code>7<\/code><\/td><td class=\"has-text-align-center\" data-align=\"center\"><code>0000-0111<\/code><\/td><td class=\"has-text-align-center\" data-align=\"center\"><code>1000-0111<\/code><\/td><td><code>1111-1001<\/code><\/td><td class=\"has-text-align-center\" data-align=\"center\"><code>01111001<\/code><\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<p>\u8bf4\u660e\uff1a<\/p>\n\n\n\n<p>\u79fb\u7801\u6709\u4e24\u79cd\u8ba1\u7b97\u65b9\u5f0f\uff0c\u7ed3\u679c\u662f\u7b49\u4ef7\u7684\uff0c\u5373\uff1a<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u76f4\u63a5\u5c06\u539f\u59cb\u6570\u636e\u52a0\u4e0a<code>2<sup>(n-1)<\/sup><\/code>\uff0c\u7136\u540e\u8f6c\u5316\u4e3a\u4e8c\u8fdb\u5236\u5373\u53ef\u4ee5<\/li>\n\n\n\n<li>\u5c06\u5176\u8865\u7801\uff0c\u6700\u9ad8\u4f4d\u8fdb\u884c\u4e00\u6b21\u7ffb\u8f6c\uff0c\u5373 <code>\u201c\u8865\u7801 XOR <code>2<sup>(n-1)<\/sup><\/code> \u201c<\/code><\/li>\n<\/ul>\n\n\n\n<h4 class=\"wp-block-heading\">\u9a8c\u8bc1\u5b58\u50a8\u65b9\u5f0f<\/h4>\n\n\n\n<p>\u4e3a\u4e86\u786e\u8ba4 InnoDB \u7684\u6574\u6570\u5904\u7406\uff0c\u518dMySQL 8.4.4\u7684\u6e90\u7801\u4e2d\u627e\u5230\u5982\u4e0b InnoDB \u5904\u7406\u6574\u578b\u6570\u636e\u7684\u4ee3\u7801\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code lang=\"c\" class=\"language-c\">  if (type == DATA_INT) {\n    \/* Store integer data in Innobase in a big-endian format,\n    sign bit negated if the data is a signed integer. In MySQL,\n    integers are stored in a little-endian format. *\/\n\n    byte *p = buf + col_len;\n\n    for (;;) {\n      p--;\n      *p = *mysql_data;\n      if (p == buf) {\n        break;\n      }\n      mysql_data++;\n    }\n\n    if (!(dtype-&gt;prtype &amp; DATA_UNSIGNED)) {\n      *buf ^= 128;\n    }\n\n    ptr = buf;\n    buf += col_len;<\/code><\/pre>\n\n\n\n<p>\u8fd9\u6bb5\u4ee3\u7801\u4e2d\uff0c\u5148\u5c06\u5b57\u8282\u5e8f\u505a\u4e86\u98a0\u5012\uff08\u4ece\u6700\u9ad8\u5b57\u8282\u4f4d\u5f00\u59cb\uff0c\u9010\u4e2a\u5b57\u8282\u8fdb\u884c\u62f7\u8d1d\u5b58\u50a8\uff09\uff0c\u5373\u5c06 MySQL \u5c42\u9762\u7684\u5c0f\u7aef\uff08little-endian\uff09\u8f6c\u5316\u4e3a\u4e86InnoDB\u5c42\u9762\u7684\uff08big-endian\uff09\u5b58\u50a8\u3002\u800c\u540e\uff0c\u518d\u5bf9\u6700\u9ad8\u4f4d\u8fdb\u884c\u4e86\u4e00\u6b21\u7ffb\u8f6c\uff0c\u5373\u8fd9\u91cc\u7684\uff1a<code>*buf ^= 128<\/code>\u64cd\u4f5c\u3002<\/p>\n\n\n\n<p>\u5373\uff1a\u5148\u5c06\u6570\u636e\u5728MySQL\u5c42\u9762\u7684\u8868\u793a\u505a\u4e86\u5927\u5c0f\u7aef\u7684\u8f6c\u5316\u5e76\u62f7\u8d1d\u8fc7\u6765\uff0c\u7136\u540e\uff0c\u5c06\u6700\u9ad8\u4f4d\u8fdb\u884c\u7ffb\u8f6c\u3002\u5373\uff0c\u5148\u5c062\u8865\u7801\u7684\u8868\u793a\u6a21\u5f0f\u62f7\u8d1d\u8fc7\u6765\uff0c\u518d\u5c06\u6700\u9ad8\u4f4d\u8fdb\u884c\u7ffb\u8f6c\u3002<\/p>\n\n\n\n<h4 class=\"wp-block-heading\">\u4ec0\u4e48\u8981\u8fd9\u4e48\u5b58\u50a8<\/h4>\n\n\n\n<p>\u5728 MySQL\/InnoDB \u5b98\u65b9\u6587\u6863\u6216\u8005\u4ee3\u7801\u4e2d\uff0c\u5e76\u6ca1\u6709\u5173\u4e8e\u8be5\u5b9e\u73b0\u7684\u8bf4\u660e\u3002\u4e0d\u8fc7\u8fd9\u4e48\u505a\uff0c\u6709\u4e00\u4e2a\u975e\u5e38\u660e\u663e\u7684\u597d\u5904\uff0c\u5373\u6240\u6709\u7684\u6574\u6570\u8868\u793a\u7684\u5927\u5c0f\u5173\u7cfb\uff0c\u4e0e\u5b9e\u9645\u5b58\u50a8\u7684\u6570\u636e\uff08\u5f53\u4e2d\u65e0\u7b26\u53f7\u578b\u5bf9\u5f85\uff09\u7684\u5927\u5c0f\u5173\u7cfb\u662f\u4e00\u81f4\u7684\u3002<\/p>\n\n\n\n<p>\u5373\uff0c\u5728\u4e0a\u8ff0\u7684\u4f8b\u5b50\u4e2d\uff1a<code>7 &gt; 1 &gt; -1 &gt; -7<\/code>\uff0c\u800c\u5bf9\u5e94\u7684\u7f16\u7801\u8868\u793a\uff0c\u4e5f\u6709\u5bf9\u5e94\u7684\u5927\u5c0f\u5173\u7cfb\uff1a<\/p>\n\n\n\n<p><code>0x80000007 &gt; 0x80000001 &gt;<code>0x7fffffff<\/code> &gt; <code>0x7ffffff9<\/code><\/code><\/p>\n\n\n\n<p>\u8fd9\u91cc\u5bf9\u8fd9\u4e2a\u95ee\u9898\u505a\u4e00\u4e2a\u7b80\u5355\u63a2\u8ba8\u3002\u5148\u8bf4\u7ed3\u8bba\u5427\uff0c\u8fd9\u662f\u4e00\u79cd\u8f83\u4e3a\u5178\u578b\u7684\u6574\u6570\u7f16\u7801\u65b9\u5f0f\uff1a<a href=\"https:\/\/en.wikipedia.org\/wiki\/Offset_binary\">Offset binary\uff08\u201c\u79fb\u7801\u201d\uff09<\/a>\u3002\u5373\uff0c\u5c06\u9700\u8981\u8868\u793a\u7684\u6574\u6570\uff0c\u52a0\u4e0a\u4e00\u4e2a\u6570\u503c\uff0c\u8ba9\u6240\u6709\u7684\u6574\u6570\u6620\u5c04\u5230\u81ea\u7136\u6570\u7a7a\u95f4\u3002\u4f8b\u5982\uff0c\u5728MySQL\u4e2d\u4f7f\u752832\u4f4d\u7684<code>int<\/code>\u7c7b\u578b\uff0c\u9700\u8981\u8868\u793a\u7684\u6574\u6570\u8303\u56f4\u4e3a<code>[-2<sup>31<\/sup>,<code>2<sup>31<\/sup><\/code>]<\/code>\u3002\u90a3\u4e48\uff0c\u5b9e\u9645\u8868\u793a\u65f6\uff0c\u5219\u52a0\u4e0a<code><code>2<sup>31<\/sup><\/code><\/code>\u3002\u66f4\u4e3a\u4e00\u822c\u7684\uff0c\u5bf9\u4e8e<code>[-2<sup>(n-1)<\/sup>, 2<sup>(n-1)<\/sup>]<\/code>\u4e4b\u95f4\u7684\u6240\u6709\u6574\u6570\u5728\u8868\u793a\u65f6\uff0c\u90fd\u52a0\u4e0a\u4e86<code>2<sup>(n-1)<\/sup><\/code>\u3002\u5373\uff0c\u5efa\u7acb\u7684\u6620\u5c04\u5173\u7cfb\u662f\uff1a<\/p>\n\n\n\n<p class=\"has-text-align-center\"> <code><code>f(i) = i + 2<sup>(n-1)<\/sup><\/code><\/code><\/p>\n\n\n\n<p>\u5373\u5bf9\u4e8e\u4efb\u4f55\u8981\u5b58\u50a8\u7684\u6574\u6570<code>i<\/code>\uff0c\u5b9e\u9645\u5b58\u50a8\u65f6\u90fd\u5b58\u50a8\u4e0a\u8ff0\u7684<code>f(i)<\/code>\u3002\u800c\u5728\u5b9e\u9645\u8fd0\u7b97\u65f6\uff0c\u5219\u662f\uff0c\u5c06\u8865\u7801\u7684\u6700\u9ad8\u4f4d\u8fdb\u884c\u4e00\u6b21\u7ffb\u8f6c\u5373\u53ef\u3002<\/p>\n\n\n\n<h4 class=\"wp-block-heading\">\u5173\u4e8e\u8865\u7801<\/h4>\n\n\n\n<p>\u4f8b\u5982\uff0c\u5728 8 \u4f4d\u4e8c\u8fdb\u5236\u4e2d\uff0c<code>00000001<\/code> \u8868\u793a <code>+1<\/code>\uff0c\u800c <code>11111111<\/code> \u4ee3\u8868 <code>-1<\/code>\u3002\u5177\u4f53\u7684\uff0c\u5728\u8868\u793a<code>-3<\/code> \u65f6\uff0c\u5148\u53d6 <code>3<\/code> \u7684\u4e8c\u8fdb\u5236 <code>00000011<\/code>\uff0c\u518d\u9010\u4f4d\u53d6\u53cd <code>11111100<\/code>\uff0c\u6700\u540e\u52a0 <code>1<\/code> \u5f97\u5230 <code>11111101<\/code>\uff0c\u5373 <code>-3<\/code> \u7684\u8865\u7801\u8868\u793a\u3002\u8fd9\u79cd\u65b9\u5f0f\u8ba9\u8ba1\u7b97\u673a\u80fd\u591f\u9ad8\u6548\u5730\u8fdb\u884c\u6574\u6570\u8fd0\u7b97\uff0c\u662f\u5178\u578b\u7684\u6b63\u8d1f\u6570\u7684\u65b9\u6cd5\uff0c\u8be5\u65b9\u6cd5\u7684\u66f4\u591a\u4f18\u52bf\u53ef\u4ee5\u53c2\u8003\uff1a<a href=\"https:\/\/en.wikipedia.org\/wiki\/Two%27s_complement\">two&#8217;s complement<\/a>\u3002<\/p>\n\n\n\n<h4 class=\"wp-block-heading\">\u8865\u5145\u8bf4\u660e<\/h4>\n\n\n\n<p>MySQL \u5c42\u9762\u7684\u6574\u6570\u8868\u793a\u548c InnoDB \u7684\u6574\u6570\u5b58\u50a8\u662f\u4e0d\u540c\u7684\u3002\u5728\u201c\u9a8c\u8bc1\u5b58\u50a8\u65b9\u5f0f\u201d\u5c0f\u7ed3\u4e2d\u7684\u4ee3\u7801\u4e2d\u53ef\u4ee5\u770b\u5230\uff1a<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>MySQL\u4f7f\u7528\u4e86\u5c0f\u7aef\uff08little-endian\uff09\uff0cInnoDB\u5c42\u9762\u4f7f\u7528\u4e86\u5927\u7aef\uff08big-endian\uff09\u5b58\u50a8<\/li>\n\n\n\n<li>\u5728 MySQL \u5c42\u9762\u4f7f\u75282-\u8865\u7801\u505a\u6709\u7b26\u53f7\u6574\u6570\u7c7b\u578b\u5b58\u50a8\uff1b\u800cInnoDB\u5c42\u9762\u4f7f\u7528\u4e86\u201c\u79fb\u7801\u201d\u5b58\u50a8<\/li>\n<\/ul>\n\n\n\n<h4 class=\"wp-block-heading\">\u53c2\u8003\u6587\u6863<\/h4>\n\n\n\n<ul class=\"wp-block-list\">\n<li><a href=\"https:\/\/en.wikipedia.org\/wiki\/Offset_binary\">Offset binary\uff08\u201c\u79fb\u7801\u201d\uff09<\/a><\/li>\n\n\n\n<li><a href=\"https:\/\/en.wikipedia.org\/wiki\/Two%27s_complement\">two&#8217;s complement<\/a><\/li>\n<\/ul>\n","protected":false},"excerpt":{"rendered":"<p>\u5b58\u50a8\u5f15\u64ce\u5728\u5b58\u50a8\u6574\u6570\u65f6\uff0c\u4e00\u822c\u4f1a\u4f7f\u7528\u6700\u9ad8\u4f4d\u4f5c\u4e3a\u6807\u5fd7\u4f4d\uff0c\u6807\u8bb0\u5b58\u50a8\u7684\u6574\u6570\u662f\u6b63\u6570\u8fd8\u662f\u8d1f\u6570\uff08\u53c2\u8003\uff09\uff0c\u6700\u9ad8\u4f4d\u4e5f\u88ab\u79f0\u4e3a\u201cmost significant bit (MSb)\u201d\u3002\u901a\u5e38\uff0c\u6700\u9ad8\u4f4d\u4e3a1\u5219\u8868\u793a\u6b63\u6570\uff0c\u6700\u9ad8\u4f4d\u4e3a0\uff0c\u5219\u8868\u793a\u8d1f\u6570\u3002\u66f4\u8fdb\u4e00\u6b65\u7684\uff0c\u8d1f\u6570\u5219\u4f1a\u901a\u8fc7\u8865\u7801\uff08\u53c2\u8003\uff1atwo&#8217;s complement\uff09\u7684\u65b9\u5f0f\u8868\u793a\u3002\u4f46\u662f\uff0cInnoDB\u6ca1\u6709\u4f7f\u7528\u8fd9\u79cd\u65b9\u6cd5\u3002 InnoDB \u7684\u6574\u6570\u5b58\u50a8 \u5728\u6b7b\u9501\u8bca\u65ad\u65f6\uff0c\u5076\u7136\u6ce8\u610f\u5230\uff0cInnoDB \u5728\u5b58\u50a8\u6574\u6570\u65f6\uff0c\u4e0e\u4e00\u822c\u7684\u7cfb\u7edf\u662f\u4e0d\u540c\u7684\u3002\u4f8b\u5982\uff0cint \u7c7b\u578b\u5b58\u50a8 1 \u7684\u65f6\u5019\uff0c\u4f7f\u7528\u7684\u8868\u793a\u662f\uff1a0x80000001\u3002\u66f4\u591a\u7684\u793a\u4f8b\u53ef\u4ee5\u53c2\u8003\u53f3\u56fe\uff1a \u6574\u6570\u503c InnoDB \u8868\u793a 1 0x80000001 -1 0x7fffffff 7 0x80000007 -7 0x7ffffff9 \u53ef\u4ee5\u770b\u5230\uff0c\u8fd9\u4e0e\u4e00\u822c\u7684\u6709\u7b26\u53f7\u578b\u7684\u6574\u6570\u5b58\u50a8\u662f\u76f8\u53cd\u7684\u3002\u5373\uff1a \u5173\u4e8e\u8fd9\u4e2a\u95ee\u9898\uff0c\u5728 Stackoverflow\u4e0a\u4e5f\u6709\u770b\u5230\u6709\u90e8\u5206\u7528\u6237\u6709\u7c7b\u4f3c\u7684\u7591\u95ee\uff1a \u672c\u6587\u5c06\u8ba8\u8bba\u4e3a\u4ec0\u4e48\u4f1a\u8fd9\u6837\u3002 \u8003\u8651 8-bit \u573a\u666f\u4e0b\u7684 \u8fd9\u91cc\u6765\u56de\u987e\u4e00\u4e0b\u201c\u4f53\u7cfb\u7ed3\u6784\u201d\u4e2d\u7684\u6700\u4e3a\u57fa\u7840\u7684\u4e00\u4e9b\u77e5\u8bc6\u5427\u3002 \u6574\u6570\u503c \u7edd\u5bf9\u503c \u7edd\u5bf9\u503c\u7684\u4e8c\u8fdb\u5236 \u539f\u7801 2-\u8865\u7801 Offset binary\uff08\u201c\u79fb\u7801\u201d\uff09 1 1 0000-0001 0000-0001 0000-0001 1000-0001 -1 1 0000-0001 1000-0001 1111-1111 0111-1111 7 7 0000-0111 0000-0111 0000-0111 [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"wp-custom-template-a-1440-px-width-template","format":"standard","meta":{"_eb_attr":"","inline_featured_image":false,"_tocer_settings":[],"footnotes":""},"categories":[6,4,137],"tags":[],"class_list":["post-17814","post","type-post","status-publish","format-standard","hentry","category-mysql","category-code-detail","category-learning-more"],"_links":{"self":[{"href":"https:\/\/www.orczhou.com\/index.php\/wp-json\/wp\/v2\/posts\/17814","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.orczhou.com\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.orczhou.com\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.orczhou.com\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.orczhou.com\/index.php\/wp-json\/wp\/v2\/comments?post=17814"}],"version-history":[{"count":20,"href":"https:\/\/www.orczhou.com\/index.php\/wp-json\/wp\/v2\/posts\/17814\/revisions"}],"predecessor-version":[{"id":17915,"href":"https:\/\/www.orczhou.com\/index.php\/wp-json\/wp\/v2\/posts\/17814\/revisions\/17915"}],"wp:attachment":[{"href":"https:\/\/www.orczhou.com\/index.php\/wp-json\/wp\/v2\/media?parent=17814"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.orczhou.com\/index.php\/wp-json\/wp\/v2\/categories?post=17814"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.orczhou.com\/index.php\/wp-json\/wp\/v2\/tags?post=17814"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}