{"id":7497,"date":"2020-04-09T11:24:39","date_gmt":"2020-04-09T03:24:39","guid":{"rendered":"https:\/\/kyle.ai\/blog\/?p=7497"},"modified":"2020-04-09T11:24:39","modified_gmt":"2020-04-09T03:24:39","slug":"%e6%88%96%e8%ae%b8%e4%bd%a0%e4%b8%8d%e7%9f%a5%e9%81%93%e7%9a%8412%e6%9d%a1sql%e6%8a%80%e5%b7%a7","status":"publish","type":"post","link":"https:\/\/kyle.ai\/blog\/7497.html","title":{"rendered":"\u6216\u8bb8\u4f60\u4e0d\u77e5\u9053\u768412\u6761SQL\u6280\u5de7"},"content":{"rendered":"<h3>\uff081\uff09\u8d1f\u5411\u6761\u4ef6\u67e5\u8be2\u4e0d\u80fd\u4f7f\u7528\u7d22\u5f15\u3002<\/h3>\n<pre><code class=\"language-sql \">select * from order where status!=0 and stauts!=1\n<\/code><\/pre>\n<p>not in\/not exists \u90fd\u4e0d\u662f\u597d\u4e60\u60ef\u3002<\/p>\n<p>\u53ef\u4ee5\u4f18\u5316\u4e3ain\u67e5\u8be2\uff1a<\/p>\n<pre><code class=\"language-sql \">select * from order where status in(2,3)\n<\/code><\/pre>\n<h3>\uff082\uff09\u524d\u5bfc\u6a21\u7cca\u67e5\u8be2\u4e0d\u80fd\u4f7f\u7528\u7d22\u5f15\u3002<\/h3>\n<pre><code class=\"language-sql \">select * from order where desc like '%XX'\n<\/code><\/pre>\n<p>\u800c\u975e\u524d\u5bfc\u6a21\u7cca\u67e5\u8be2\u5219\u53ef\u4ee5\uff1a<\/p>\n<pre><code class=\"language-sql \">select * from order where desc like 'XX%'\n<\/code><\/pre>\n<h3>\uff083\uff09\u6570\u636e\u533a\u5206\u5ea6\u4e0d\u5927\u7684\u5b57\u6bb5\u4e0d\u5b9c\u4f7f\u7528\u7d22\u5f15\u3002<\/h3>\n<pre><code class=\"language-sql \">select * from user where sex=1\n<\/code><\/pre>\n<p>\u539f\u56e0\uff1a\u6027\u522b\u53ea\u6709\u7537\uff0c\u5973\uff0c\u6bcf\u6b21\u8fc7\u6ee4\u6389\u7684\u6570\u636e\u5f88\u5c11\uff0c\u4e0d\u5b9c\u4f7f\u7528\u7d22\u5f15\u3002<\/p>\n<p>\u7ecf\u9a8c\u4e0a\uff0c\u80fd\u8fc7\u6ee480%\u6570\u636e\u65f6\u5c31\u53ef\u4ee5\u4f7f\u7528\u7d22\u5f15\u3002\u5bf9\u4e8e\u8ba2\u5355\u72b6\u6001\uff0c\u5982\u679c\u72b6\u6001\u503c\u5f88\u5c11\uff0c\u4e0d\u5b9c\u4f7f\u7528\u7d22\u5f15\uff0c\u5982\u679c\u72b6\u6001\u503c\u5f88\u591a\uff0c\u80fd\u591f\u8fc7\u6ee4\u5927\u91cf\u6570\u636e\uff0c\u5219\u5e94\u8be5\u5efa\u7acb\u7d22\u5f15\u3002<\/p>\n<h3>\uff084\uff09\u5728\u5c5e\u6027\u4e0a\u8fdb\u884c\u8ba1\u7b97\u4e0d\u80fd\u547d\u4e2d\u7d22\u5f15\u3002<\/h3>\n<pre><code class=\"language-sql \">select * from order where YEAR(date) &lt; = '2020'\n<\/code><\/pre>\n<p>\u5373\u4f7fdate\u4e0a\u5efa\u7acb\u4e86\u7d22\u5f15\uff0c\u4e5f\u4f1a\u5168\u8868\u626b\u63cf\uff0c\u53ef\u4f18\u5316\u4e3a\u503c\u8ba1\u7b97\uff1a<\/p>\n<pre><code class=\"language-sql \">select * from order where date &lt; = CURDATE()\n<\/code><\/pre>\n<p>\u6216\u8005\uff1a<\/p>\n<pre><code class=\"language-sql \">select * from order where date &lt; = '2020-01-01'\n<\/code><\/pre>\n<h3>\uff085\uff09\u5982\u679c\u4e1a\u52a1\u5927\u90e8\u5206\u662f\u5355\u6761\u67e5\u8be2\uff0c\u4f7f\u7528Hash\u7d22\u5f15\u6027\u80fd\u66f4\u597d\uff0c\u4f8b\u5982\u7528\u6237\u4e2d\u5fc3\u3002<\/h3>\n<pre><code class=\"language-sql \">select * from user where uid=?\nselect * from user where login_name=?\n<\/code><\/pre>\n<p>\u539f\u56e0\uff1a<\/p>\n<ul>\n<li>B-Tree\u7d22\u5f15\u7684\u65f6\u95f4\u590d\u6742\u5ea6\u662fO(log(n))\uff1b<\/li>\n<li>Hash\u7d22\u5f15\u7684\u65f6\u95f4\u590d\u6742\u5ea6\u662fO(1)\u3002<\/li>\n<\/ul>\n<h3>\uff086\uff09\u5141\u8bb8\u4e3anull\u7684\u5217\uff0c\u67e5\u8be2\u6709\u6f5c\u5728\u5927\u5751\u3002<\/h3>\n<p>\u5355\u5217\u7d22\u5f15\u4e0d\u5b58null\u503c\uff0c\u590d\u5408\u7d22\u5f15\u4e0d\u5b58\u5168\u4e3anull\u7684\u503c\uff0c\u5982\u679c\u5217\u5141\u8bb8\u4e3anull\uff0c\u53ef\u80fd\u4f1a\u5f97\u5230\u201c\u4e0d\u7b26\u5408\u9884\u671f\u201d\u7684\u7ed3\u679c\u96c6\u3002<\/p>\n<pre><code class=\"language-sql \">select * from user where name != 'shenjian'\n<\/code><\/pre>\n<p>\u5982\u679cname\u5141\u8bb8\u4e3anull\uff0c\u7d22\u5f15\u4e0d\u5b58\u50a8null\u503c\uff0c\u7ed3\u679c\u96c6\u4e2d\u4e0d\u4f1a\u5305\u542b\u8fd9\u4e9b\u8bb0\u5f55\u3002<\/p>\n<p>\u6240\u4ee5\uff0c\u8bf7\u4f7f\u7528not null\u7ea6\u675f\u4ee5\u53ca\u9ed8\u8ba4\u503c\u3002<\/p>\n<h3>\uff087\uff09\u590d\u5408\u7d22\u5f15\u6700\u5de6\u524d\u7f00\uff0c\u5e76\u4e0d\u662f\u6307SQL\u8bed\u53e5\u7684where\u987a\u5e8f\u8981\u548c\u590d\u5408\u7d22\u5f15\u4e00\u81f4\u3002<\/h3>\n<p>\u7528\u6237\u4e2d\u5fc3\u5efa\u7acb\u4e86(login_name, passwd)\u7684\u590d\u5408\u7d22\u5f15<\/p>\n<pre><code class=\"language-sql \">select * from user where login_name=? and passwd=?\nselect * from user where passwd=? and login_name=?\n<\/code><\/pre>\n<p>\u90fd\u80fd\u591f\u547d\u4e2d\u7d22\u5f15\u3002<\/p>\n<pre><code class=\"language-sql \">select * from user where login_name=?\n<\/code><\/pre>\n<p>\u4e5f\u80fd\u547d\u4e2d\u7d22\u5f15\uff0c\u6ee1\u8db3\u590d\u5408\u7d22\u5f15\u6700\u5de6\u524d\u7f00\u3002<\/p>\n<pre><code class=\"language-sql \">select * from user where passwd=?\n<\/code><\/pre>\n<p>\u4e0d\u80fd\u547d\u4e2d\u7d22\u5f15\uff0c\u4e0d\u6ee1\u8db3\u590d\u5408\u7d22\u5f15\u6700\u5de6\u524d\u7f00\u3002<\/p>\n<h3>\uff088\uff09\u4f7f\u7528ENUM\u800c\u4e0d\u662f\u5b57\u7b26\u4e32\u3002<\/h3>\n<p>ENUM\u4fdd\u5b58\u7684\u662fTINYINT\uff0c\u522b\u5728\u679a\u4e3e\u4e2d\u641e\u4e00\u4e9b\u201c\u4e2d\u56fd\u201d\u201c\u5317\u4eac\u201d\u201c\u6280\u672f\u90e8\u201d\u8fd9\u6837\u7684\u5b57\u7b26\u4e32\uff0c\u5b57\u7b26\u4e32\u7a7a\u95f4\u53c8\u5927\uff0c\u6548\u7387\u53c8\u4f4e\u3002<\/p>\n<h3>\uff089\uff09\u5982\u679c\u660e\u786e\u77e5\u9053\u53ea\u6709\u4e00\u6761\u7ed3\u679c\u8fd4\u56de\uff0climit 1\u80fd\u591f\u63d0\u9ad8\u6548\u7387\u3002<\/h3>\n<pre><code class=\"language-sql \">select * from user where login_name=?\n<\/code><\/pre>\n<p>\u53ef\u4ee5\u4f18\u5316\u4e3a\uff1a<\/p>\n<pre><code class=\"language-sql \">select * from user where login_name=? limit 1\n<\/code><\/pre>\n<p>\u539f\u56e0\uff1a\u4f60\u77e5\u9053\u53ea\u6709\u4e00\u6761\u7ed3\u679c\uff0c\u4f46\u6570\u636e\u5e93\u5e76\u4e0d\u77e5\u9053\uff0c\u660e\u786e\u544a\u8bc9\u5b83\uff0c\u8ba9\u5b83\u4e3b\u52a8\u505c\u6b62\u6e38\u6807\u79fb\u52a8\u3002<\/p>\n<h3>\uff0810\uff09\u628a\u8ba1\u7b97\u653e\u5230\u4e1a\u52a1\u5c42\u800c\u4e0d\u662f\u6570\u636e\u5e93\u5c42\uff0c\u9664\u4e86\u8282\u7701\u6570\u636e\u7684CPU\uff0c\u8fd8\u6709\u610f\u60f3\u4e0d\u5230\u7684\u67e5\u8be2\u7f13\u5b58\u4f18\u5316\u6548\u679c\u3002<\/h3>\n<pre><code class=\"language-sql \">select * from order where date &lt; = CURDATE()\n<\/code><\/pre>\n<p>\u8fd9\u4e0d\u662f\u4e00\u4e2a\u597d\u7684SQL\u5b9e\u8df5\uff0c\u5e94\u8be5\u4f18\u5316\u4e3a\uff1a<\/p>\n<pre><code class=\"language-php \">$curDate = date('Y-m-d');\n$res = mysql_query(\n    'select * from order where date &lt; = $curDate'\n);\n<\/code><\/pre>\n<p>\u539f\u56e0\uff1a\u91ca\u653e\u4e86\u6570\u636e\u5e93\u7684CPU\u3002\u591a\u6b21\u8c03\u7528\uff0c\u4f20\u5165\u7684SQL\u76f8\u540c\uff0c\u624d\u53ef\u4ee5\u5229\u7528\u67e5\u8be2\u7f13\u5b58\u3002<\/p>\n<h3>\uff0811\uff09\u5f3a\u5236\u7c7b\u578b\u8f6c\u6362\u4f1a\u5168\u8868\u626b\u63cf<\/h3>\n<pre><code class=\"language-sql \">select * from user where phone=13800001234\n<\/code><\/pre>\n<p>\u4f60\u4ee5\u4e3a\u4f1a\u547d\u4e2dphone\u7d22\u5f15\u4e48\uff1f\u5927\u9519\u7279\u9519\u4e86\uff01\uff01\uff01<\/p>\n<p>\u672b\u4e86\uff0c\u518d\u52a0\u4e00\u6761\uff0c\u4e0d\u8981\u4f7f\u7528select &#42;\uff08\u6f5c\u53f0\u8bcd\uff0c\u6587\u7ae0\u7684SQL\u90fd\u4e0d\u5408\u683c =&#95;=\uff09\uff0c\u53ea\u8fd4\u56de\u9700\u8981\u7684\u5217\uff0c\u80fd\u591f\u5927\u5927\u7684\u8282\u7701\u6570\u636e\u4f20\u8f93\u91cf\uff0c\u4e0e\u6570\u636e\u5e93\u7684\u5185\u5b58\u4f7f\u7528\u91cf\u54df\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\uff081\uff09\u8d1f\u5411\u6761\u4ef6\u67e5\u8be2\u4e0d\u80fd\u4f7f\u7528\u7d22\u5f15\u3002 select * from order where status!=0 an [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[4],"tags":[],"class_list":["post-7497","post","type-post","status-publish","format-standard","hentry","category-skill"],"_links":{"self":[{"href":"https:\/\/kyle.ai\/blog\/wp-json\/wp\/v2\/posts\/7497","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/kyle.ai\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/kyle.ai\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/kyle.ai\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/kyle.ai\/blog\/wp-json\/wp\/v2\/comments?post=7497"}],"version-history":[{"count":1,"href":"https:\/\/kyle.ai\/blog\/wp-json\/wp\/v2\/posts\/7497\/revisions"}],"predecessor-version":[{"id":7498,"href":"https:\/\/kyle.ai\/blog\/wp-json\/wp\/v2\/posts\/7497\/revisions\/7498"}],"wp:attachment":[{"href":"https:\/\/kyle.ai\/blog\/wp-json\/wp\/v2\/media?parent=7497"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/kyle.ai\/blog\/wp-json\/wp\/v2\/categories?post=7497"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/kyle.ai\/blog\/wp-json\/wp\/v2\/tags?post=7497"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}